Nuclear waste management of the Olkiluoto and Loviisa power plants

Summary of the activities during 2009

Images in the cover demonstrate the welding of the copper canister lid,inspection station for canister sealing weld,

the substation of the canister lift and backfilling of deposition tunnel.Images are from the Final disposal and encapsulation -animation

that was completed in 2009.

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Abstract

This report is a summary of nuclear waste management activities during 2009 for the Olkiluoto and Loviisa power plants. The summary includes a report of the status and actions of nu-clear waste management by the power companies in 2009, as prescribed by the Nuclear Energy Act and Decree.

In 2000, the Government made a decision-in-principle regarding Posiva’s application for final disposal of spent fuel in Olkiluoto, Eurajoki. In 2003, the Ministry of Trade and Industry decided that the preliminary reports and plans required for the construction licence of the final disposal facility must be sub-mitted during 2009. The construction licence must be applied for by the end of 2012.

Preparations for the disposal of spent fuel are progressing in line with the long-term programme of research, tech-nical design and development (abbre-viated TKS in Finnish). The year 2009 was still part of the three-year period described in the TKS-2006 programme. The new TKS-2009 programme was published in the autumn of 2009. It contains an account of the planned actions and their preparations during 2010–2012.

At the end of 2009, the quantity of spent fuel in storage at the Olkiluoto power plant amounted to a total of 7,212 bundles containing an approximate to-tal of 1,220 tonnes of uranium. At the same time, the quantity of spent fuel in storage at the Loviisa power plant amounted to a total of 3,961 bundles corresponding to an approximate quan-tity of 477 tonnes of fresh uranium.

The layout of ONKALO was revised during 2009 to better correspond to the needs of vertical and horizontal disposal. In addition, the plans further specified the extent of ONKALO to be implemented

before submitting the construction licence application in 2012. During the year, the access tunnel was excavated up to chainage 4059. The bedrock has been of relatively good quality.

The EDZ 09 programme was estab-lished as a continuation of the EDZ 300 programme reported in the spring 2009 because the open questions out-standing from the previous programme required further investigations. In con-junction with the new programme, an investigation niche was also quarried at chainage 3620. The project report will be completed in early 2010.

In canister design, a number of sup-plementary analyses were conducted during 2009 in order to verify that the technical requirements are met. The analyses will continue during 2010. Po-siva produced a report on the current status of development work concern-ing the canister manufacturing process. It contains a summary of the develop-ment work for canister components and their associated manufacturing tests, a comparison of different manufacturing methods as well as an account of the current situation regarding manufac-turing capabilities of canister compo-nents. Canister lid weld tests were con-ducted in 2009 in compliance with the preliminary welding instructions devel-oped earlier.

The development work for bentonite buffer has continued in line with the development programme produced by Posiva. The work has consisted of the bentonite buffer design work and study-ing its associated parameters as well as development of the manufacturing and installation processes for bentonite blocks.

The most substantial operation dur-ing 2009 was that of preparing the back-fill plan for deposition tunnels and re-

porting the work carried out during the TKS period approaching its completion. The plan is based on pre-compacted blocks surrounded by pellet backfill as well as a floor levelling layer, and the quantities of different components in-volved have been revised from the pre-vious plan. The requirements have also been worked on with a view to develop-ing the deposition tunnel excavation process.

Three new boreholes were drilled in the eastern part of the Olkiluoto site in 2009. They were utilised for continu-ing the general characterisation work of the eastern area with respect to the geological, hydrogeological and hydro-geochemical properties of the bedrock as well as for studying the eastern line-ament bounding the island of Olkiluoto. An investigation trench was made near borehole OL-KR51, and a geological mapping survey was carried out for it. The sampling of water from deep bore-holes concentrated on holes drilled in 2008.

Research was carried out in ONKA-LO during 2009 in order to establish the excavation induced changes and the properties of the bedrock surround-ing ONKALO. The research activities in ONKALO included mapping, probing hole measurements, drilling studies, groundwater sampling, flow measure-ments and rock-mechanical measure-ments. Pilot holes were drilled in the access tunnel of ONKALO at chainag-es 3459 and 3922. The drilling of pilot holes and the associated hole surveys interrupted the excavation operations.

As in previous years, the modelling of the Olkiluoto site is coordinated by the Olkiluoto Modelling Task Force whose work involves interpretation and mod-elling work of the different research disciplines (geology, hydrogeology,

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geochemistry and rock mechanics), aimed at complementing the under-standing of the site. The Olkiluoto Site Description 2008, the third successive description of the disposal site, was published in 2009. It includes updated models from all lines of research.

The outline design phases of both the encapsulation plant and the reposi-tory ended at the end of 2009 with a report on the status of planning at that stage. The primary alternative is still an encapsulation plant connected to the repository by a canister shaft. The de-sign and planning work for the dispos-al facility has been carried out in close co-operation with the implementation planning work for ONKALO in order to ensure the compatibility of facilities. The layout of repository facilities was updated in the plan on the basis of the latest bedrock data.

The major tasks in 2009 aimed at producing the safety principles includ-ed in the work for compiling a report on Models and data. This report will be completed in 2010. Preparations were also made in 2009 for a summary report concerning the Safety Case, and it will also be completed in 2010.

Biosphere-related work took place during 2009 according to the TKS-2006 programme, a separate biosphere work plan and the revised Safety Case plan. The goal of this work was to produce an updated description of the biosphere, forecasts for the future terrain and ec-osystems, as well as radionuclide mi-gration simulations and a dose assess-ment. Reports concerning these will be completed in early 2010.

In parallel with the vertical disposal solution now constituting Posiva’s

reference solution, the horizontal dis-posal solution has been developed joint-ly with Svensk Kärnbränslehantering AB (SKB). The decision to continue the de-velopment work for the horizontal dis-posal solution was taken in the spring 2008. The main goal of planning during the current project phase is to resolve the questions identified as important during the previous phase of the study. Many of these questions are related to the buffer and its behavior.

The long-term changes possibly caused by the construction of ONKA-LO are monitored using a special pro-gramme established for the purpose. The results of monitoring studies are published separately for each field of re-search as part of the series of Posiva’s working reports.

Posiva has produced a nuclear non-proliferation control manual that de-scribes the nuclear non-proliferation control during the construction phase of ONKALO until 2012. The nuclear non-proliferation control manual was updated in 2009.

The EIA procedure regarding the ex-pansion of the repository, started in 2008, was completed when the Ministry of Employment and the Economy issued its statement in March 2009 regarding the EIA Report. Immediately after that, Posiva submitted its decision-in-prin-ciple application for depositing spent nuclear fuel from Loviisa 3.

In September 2009, TVO and Fortum submitted a status report to the Minis-try of Employment and the Economy regarding the state of preparations for the documents required for the con-struction licence application for the en-capsulation plant and the repository. In

the same connection, Posiva submitted draft attachments to the construction li-cence application. At the end of 2009, Posiva submitted to STUK (the Radia-tion and Nuclear Safety Authority) pre-liminary versions of the licensing doc-uments referred to in section 32 of the Nuclear Energy Decree.

The well-established practical meas-ures regarding operating waste from Olkiluoto and Loviisa were continued, as were the research and study projects on this subject. The total amount of operating waste accumulated at the Olkiluoto power plant by the end of 2009 was 6,407 m3. Of the waste orig-inating from Olkiluoto, 5,244 m3 has been disposed of in the VLJ repository in Olkiluoto. In Loviisa, trial operation runs of the liquid waste solidification plant using cementing/concrete tech-niques took place during 2008–2009. The studies during operation of the Loviisa repository facilities continued in 2009 in line with the monitoring plan. Of the waste originating from Loviisa, 1,610 m3 has been disposed of in the VLJ repository in Hästholmen.

A report was produced during 2009 in Olkiluoto regarding the decommis-sioning costs of the OL3 plant unit. The results will be presented in the pre-liminary decommissioning plan for the OL3 plant unit. The studies carried out in Loviisa included one on the licens-ing process for decommissioning and the project comparing the separation of storage pool no. 2 for spent fuel as an independent unit to the dry storage of spent fuel in containers at the Loviisa power plant.

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Table of contents

ABSTRACT .............................................................................................................................. 3

INTRODUCTION ................................................................................................................... 7

SPENT FUEL MANAGEMENT ............................................................................................... 8

Operating principle and time schedule ............................................................................ 8

Present status of storage operations ................................................................................ 8

ONKALO ............................................................................................................................... 10

Planning/design of ONKALO .......................................................................................... 10

The construction of ONKALO ......................................................................................... 10

Development of construction methods .......................................................................... 10

DEVELOPMENT OF THE DISPOSAL SOLUTION .............................................................. 12

Spent fuel .......................................................................................................................... 12

Disposal canister .............................................................................................................. 12

Bentonite buffer ............................................................................................................... 16

Backfilling of deposition tunnels and closure of the facilities ........................................ 17

Bedrock characteristics at the disposal site .................................................................... 17

DESIGN AND PLANNING OF THE ENCAPSULATION PLANT AND REPOSITORY ....... 22

Encapsulation plant ......................................................................................................... 22

Repository ........................................................................................................................ 23

PRODUCTION OF EVIDENCE IN SUPPORT OF THE SAFETY CASE ............................... 24

Plan for the production of evidence in support of the Safety Case ............................... 24

Performance of release barriers ...................................................................................... 24

Bedrock as a release barrier ............................................................................................. 25

Biosphere ......................................................................................................................... 26

General research .............................................................................................................. 26

DEVELOPMENT OF THE HORIZONTAL DISPOSAL SOLUTION .................................... 28

OLKILUOTO MONITORING PROGRAMME ...................................................................... 30

Rock mechanics ............................................................................................................... 30

Hydrological features ...................................................................................................... 30

Hydrogeochemistry .......................................................................................................... 31

The environment .............................................................................................................. 31

Foreign materials ............................................................................................................. 32

CONTROL OF NUCLEAR MATERIALS AND NUCLEAR NON-PROLIFERATION

CONTROL .............................................................................................................................. 33

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OPERATING WASTE MANAGEMENT ................................................................................ 34

The Olkiluoto power plant ............................................................................................... 34

The Loviisa power plant .................................................................................................. 36

DECOMMISSIONING REPORTS ......................................................................................... 41

The Olkiluoto power plant ................................................................................................ 41

The Loviisa power plant ................................................................................................... 41

OTHER ACTIVITIES .............................................................................................................. 43

Management of quality and the environment ................................................................ 43

Licences and permits ....................................................................................................... 43

Management of research data ........................................................................................ 43

PROVISIONS FOR THE COST OF NUCLEAR WASTE MANAGEMENT ........................... 45

LIST OF REPORTS ................................................................................................................ 46

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There are two companies using nuclear power to generate electricity in Finland, Teollisuuden Voima Oyj (hereinafter ”TVO”) and Fortum Power and Heat Oy (hereinafter ”Fortum”). According to the Nuclear Energy Act, TVO and For-tum are responsible for all procedures related to the management of the waste they have produced, and their appropri-ate preparation and related expenses.

According to the Nuclear Energy Act, the Ministry of Employment and the Economy (abbreviated TEM in Finnish) decides on the principles to be followed in nuclear waste management. These principles were presented by the Min-istry of Trade and Industry (abbreviated

KTM in Finnish; its duties are now looked after by TEM) in its decisions of 19 March 1991, 26 September 1995 and 23 October 2003, and these decisions form the basis for both the practical implementation of nuclear waste man-agement and the R&D work concerning future operations.

Posiva Oy (hereinafter ”Posiva”) is a company jointly owned by the above companies. It is in charge of R&D work aimed at the final disposal of spent nu-clear fuel as well as the construction and operation of the encapsulating plant and repository at a later stage. TVO and Fortum will separately take care of all operations related to the handling and

final disposal of low- and intermediate-level operating waste and to the decom-missioning of power plants.

Posiva is responsible for producing the annual report on nuclear waste man-agement operations at the Olkiluoto and Loviisa nuclear power plants. This is the report on operations in 2009; it contains the report required by the Nu-clear Energy Act and Decree on the sta-tus of nuclear waste management at the said power companies in 2009, as well as a report of the preparations made for the future costs of nuclear waste management.

Introduction

Teollisuuden Voima Oyj has two boiling water reactors in Olkiluoto, Eurajoki, each with a rated electrical output of 860 MWe. Olkiluoto 1 (OL1) was first con-nected to the national grid in September 1978, followed by Olkiluoto 2 (OL2) in February 1980. In 2009, the utilisation rate of OL1 was 97,0 % while that of OL2 was 95,1 %. The operating licences for the OL1 and OL2 power plant units and the low-level waste (MAJ storage), intermediate-level waste (KAJ storage) and interim spent fuel storage (KPA storage) are valid until the end of 2018. The operating licence for the Olkiluoto repository for operating waste (VLJ re-pository) is valid until the end of 2051. A third NPP unit is also under construc-tion in Olkiluoto, i.e. the Olkiluoto 3 (OL3) unit.

The Loviisa power plant of Fortum Power and Heat Oy has two pressurized water reactors, both with a rated electrical output of 488 MWe. The commercial operation of Loviisa 1 (LO1) began in May 1997, and that of Loviisa 2 (LO2) in January 1981. in 2009, the utilisation rate of LO1 was 96,0 % while that of LO2 was 95,4 %. The operating licences for the LO1 and LO2 plant units and for their nuclear fuel and nuclear waste management facilities are valid until the end of 2027 for LO1 and until the end of 2030 for LO2. The operating licence for the reactor waste repository (VLJ repository) is valid until the end of 2055.

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Spent fuel management

Overall time schedule for nuclear waste management.

Operating principle and time schedule

In compliance with the Nuclear Energy Act and decisions of the KTM, prepa-rations are made for disposing of all spent fuel currently held at the Olkiluo-to and Loviisa plants inside the Finnish bedrock. In its decision of 23 October 2003, the KTM changed the schedule of preparations for the disposal of spent fuel so that the preliminary reports and plans required for the construction li-cence for the encapsulation plant and the repository must be submitted in 2009. The final reports and plans must be available by the end of 2012. The fi-nal disposal operations are scheduled to commence in 2020. Before that, the temporary storage of spent fuel takes place on the power plant sites.

In December 2000, the Government made a decision-in-principle regarding

Posiva’s application for final disposal of spent fuel in Olkiluoto, Eurajoki. Parlia-ment ratified the decision almost unan-imously in May 2001. The decision-in-principle remains valid until 17 May 2016.

A decision-in-principle concerning a new nuclear power plant unit (OL3) to be built in Finland was made in 2002. At the same time, a decision-in-principle concerning the construction of the re-pository for spent nuclear fuel as an ex-panded facility was made so that spent fuel from OL3 can also be disposed of in the repository. The nuclear waste management obligation of the OL3 plant unit only begins when the plant is operational.

Preparations for the disposal of spent fuel are progressing in line with the long-term (TKS) programme of re-search, technical design and develop-ment published in 2000 (Posiva 2000-14). The three-year period including

2009 (2007–2009) was described in the TKS-2006 programme published in 2006. The TKS-2009 programme, describing the activities planned for 2010–2012 and their preparations, was published in September 2009.

Present status of storage operations

The fuel spent in Olkiluoto is tempo-rarily stored in the power plant units and in the interim spent fuel storage (KPA storage) at the power plant site. In 2009, the available storage capacity in the KPA storage amounted to 7,146 storage positions. The KPA storage fa-cility can accommodate the spent fuel of approximately 30 years worth of pro-duction at the OL1 and OL2 units.

The KPA storage expansion project began in 2009. The site and construc-tion work is scheduled for 2010–2013

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so that the extension could be commis-sioned in early 2014. The premises of the expansion work are the exhaustion of storage capacity at the OL1 and OL2 plant units as well as the future needs of OL3. Three pools will be constructed in the expansion project. A new pool must be in operation for the OL1 and OL2 plant units in 2014, while the OL3 unit is expected to need its first pool in 2018. The expansion project is imple-mented as a structural alteration project of a nuclear facility. The OL1/OL2 ope-rating licence has ample capacity for storing the fuel from these units. The permission for expanding the capacity and for storing fuel to accommodate for the needs of OL3 will be applied for in connection with the operating licence application for OL3.

During the year being reported, the 30th refuelling operation took place at OL1 and the 28th at OL2. At the end of the year, the quantity of spent fuel in storage amounted to a total of 7,212 bundles containing an approximate to-tal of 1,220 tonnes of uranium. Of all the bundles in storage, 6,150 were placed in the KPA storage, 502 in the water pools of OL1 and 560 at OL2. Additionally, 500 assemblies were in use in the OL1 reac-tor, with another 500 in use in the OL2 reactor. The figures include fuel placed in fuel rod racks (one per plant) used for the storage of damaged fuel rods.

Spent fuel produced in Loviisa is also stored at the power plant and in the in-terim spent fuel storage. New spent fuel storage pools were last constructed at the Loviisa site in 2000. A decision has

been made to equip the current pools with high-density racks. This will provide additional capacity until 2020 when the transportation of spent fuel for disposal is expected to start. Two new racks were procured in both 2007 and 2009. Two more racks will be procured in each of the years 2011, 2015 and 2017.

At the end of 2009, the quantity of spent fuel in storage at the Loviisa pow-er plant amounted to a total of 3,961 bundles corresponding to an approxi-mate quantity of 477 tonnes of fresh uranium. Of that number, 294 assem-blies were stored at LO1 and 336 at LO2. Spent fuel storages 1 and 2 held 480 and 2,851 bundles, respectively. Addition-ally, 313 assemblies were in use in the LO1 reactor, with another 313 in use in the LO2 reactor.

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ONKALO

ONKALO, the underground research fa-cility, provides accurate information for the detailed design of repository facilities and for assessing the safety and construction engineering solutions. ONKALO allows for the testing of disposal techniques in actual conditions. The building permit application for ONKALO was submitted to the Mu-nicipality of Eurajoki in May 2003, and the construction work began in June 2004. The construction phase now in progress will ad-vance to level -420 m. The technical facili-ties required for disposal operations will be located at level -437 m. Research activities have taken place in ONKALO ever since the construction work began.

Planning/design of ONKALO

The layout design work for ONKALO has been carried out in parallel with the design work for the repository. The layout of ONKALO was revised during 2009 to better accommodate the needs of the KBS-3H and KBS-3V solutions. The extent to which ONKALO will be im-plemented before submitting the con-struction licence application was also further specified in the plans.

The preliminary plans for tunnel con-tract TU5 were produced during the summer 2009. The section of access tunnel included in tunnel contract TU4 ends at the approximate level of -420 m from where the access tunnel will con-tinue to the technical facilities located at level -437 m. The TU5 plans include architectural, construction engineer-ing and rock engineering design work. These plans will be submitted to the Radiation and Nuclear Safety Authority (STUK) for inspection in compliance with the preliminary inspection pro-cedure at the beginning of 2010, two months before the subject contract is

scheduled to start. This preliminary in-spection procedure was introduced at the TU4 phase.

Planning during the on-going work on TU4 and inspection of plans to the extent required by the work took place in 2009. Planning during the on-going work on TU4, the contract that began in August 2008, will continue in early 2010.

The planning of HPAC work and elec-trical work has continued for the on-go-ing contracts (HPAC4 and E4) during the whole year as planning carried out during production.

The construction of ONKALO

During the year, the excavation of the access tunnel advanced to chainage 4059. The chainage number corre-sponds to the length of the access tun-nel in metres. The personnel and venti-lation shafts had already been drilled to level -290 m, and preparations for raise boring were made during 2009 up to the level of -437 m.

The bedrock quality has been relatively good, and there has been little need for

grouting. During the year, the tunnels were systematically reinforced using both bolts and fibre-reinforced shot-crete. This was, among other things, done in order to ensure appropriate safety at work in spite of increased stresses in the bedrock.

The HPAC and electrical work for the access tunnel progressed as planned and reached chainage 3700 at the end of the year. There were no significant qual-ity deviations or environmental damage during the year. The communication of construction work progress to public authorities has continued in compliance with what has been agreed.

Development of construction methods

GROUTING OPERATIONSBedrock sealing in compliance with the grouting method developed in the R20 programme was tried out in the autumn 2009. The utilisation of this method will be further developed over the course of the normal production process. The purpose of the method developed is

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to grout the bedrock using low-pH cement, smaller volumes of cement and fewer metres of holes remaining outside the tunnel profile. In addition, colloidal silica was added to the materials to be used for sealing, and it was tested in pilot grouting operations.

MANAGEMENT OF EXCAVATION DAMAGED ZONESExcavation reduces the ability of bed-rock to constrict the flow of ground-water. Part of this change is caused by the dynamic, immediate load exerted by the explosion. This is evidenced by so-called Excavation Damaged Zone, or EDZ. EDZ and their management is one area determined by Posiva as hav-ing a significant impact on the long-term safety of disposal. This is why EDZ management has a central role in Posiva’s development activities imple-mented through different programmes and R&D projects.

The EDZ 300 programme was imple-mented during 2007–2008 and report-ed in Posiva’s Working Report 2008-66 in the spring 2009. The production and verification methods tested during the programme proved to be feasible, although in need of certain further ac-tions. That is why a new R&D project (EDZ 09) was established. Its goals included:– development of the management of excavation operations,– taking geological conditions and the deployed excavation parameters into account in the modelling of fracture formation,– further studies regarding the use of ground penetrating radar,– conduct of parallel comparison studies,– improving the usefulness of ground penetrating radar as a verification tool, and– testing of other geophysical methods providing comparison values.

The EDZ 09 programme was estab-lished, among other reasons, because the open questions outstanding from the previous programme required fur-ther investigations. The purpose of the

project is to further develop the meth-ods and produce new information for determining the significance of EDZs. However, assessing the implications of EDZ on long-term safety is not included within the scope of this project.

The functional objective of the project is to produce information that can be utilised for setting the require-ments for taking EDZ into account in planning and implementation when the excavation of ONKALO continues. The fact that assessing the impact of EDZ on long-term safety may include con-siderable uncertainties will be taken into account when producing the material.

The work in the project is aimed at introducing the EDZ verification and assessment methods and zone con-trolling procedures to excavation work before tunnel excavation work contin-ues after TU4.

The project was initiated in late 2008, and the excavation of the investigation niche (PL3620) began in the spring 2009. The location and cross-section of the tunnel were chosen to correspond, as closely as possible, to the disposal conditions. The excavation work was completed in the autumn, after which the measurements for verifying excava-tion damage and the associated com-parison tests could commence. The field work was completed in early No-vember 2009 and the processing of the results and their reporting could begin.

The results required by the goals set were achieved by comparing the im-pact of different excavation methods and by developing the excavation proc-ess. It was shown that the excavation parameters affecting the degree of ex-cavation damage can be identified and managed, although some suggestions for improvement were also made. The partial report regarding excavation will be completed in February 2010. The prediction of excavation damage using the calculation methods has, so far, not produced results useful for the project. This is because the geological condi-tions in the studied subject vary exten-sively, and testing them is very difficult and time-consuming.

Measurements before and after exca-vation concentrated on the applied use of ground penetrating radar for observ-ing excavation damage. This practice was started in the previous programme. It was found during the previous pro-gramme that the ground penetrating radar can be used to evidence that the excavation damage caused by well-con-trolled excavation can be detected with sufficient reliability. Observations made with the ground penetrating radar were compared with other results that were obtained from microseismic tests, hy-drological measurements and geologi-cal mapping carried out at the same spots. The method proved to be even more suitable for a verification tool than was previously thought. This opinion is supported by both the ground pene-trating radar observations and seismic measurements and other geophysical measurements made for comparison purposes. The measurement results material is extensive and requires plenty of cross-comparisons. The work will be completed in March 2010.

The results of the project will be uti-lised for requirements management of future demonstration operations and for guiding the planning work. The develop-ment of excavation methods will con-tinue by verification of drilling accuracy and the application of the methods on the construction of repository facilities. The utilisation of ground penetrating ra-dar for verifying excavation damage will be further developed.

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Development of the disposal solution

The disposal solution foreseen for the spent fuel produced by TVO and Fortum is originally based on the KBS-3 solution developed SKB. The spent fuel bundles are in-serted into copper-cast iron canisters and placed several hundred metres deep inside the bedrock. Compacted ben-tonite blocks are placed in the deposition holes between the rock and the canister. When the disposal operations are finished, all quarried facilities and access routes to the repository are backfilled and sealed off.

The canister, bentonite and bedrock form a multi-barrier against the release of radioactive substances. The copper shell of the canister has excellent resistance against ground-water-induced corrosion, and the cast iron insert ensures mechanical durability. Bentonite restricts the access of groundwater to the canister surface and protects the can-

ister from minor bedrock movements. The conditions sur-rounding the canister deep inside the bedrock will remain stable for long periods of time. The bedrock also protects the deposited fuel from external interference.

Spent fuel

It is important for the safety of disposal that it is known how quickly radioactive substances may be released from spent fuel and how quickly the fuel may dis-solve when it comes into contact with water after disposal. Spent fuel mainly consists of uranium dioxide (UO2, about 96%). UO2 represents a reduced state of uranium where the oxidation state of uranium is U(IV). UO2 has low solubility and it is stable in reducing groundwater conditions. If water penetrates a dam-aged canister, the solubility of the UO2 matrix is a critical parameter when as-sessing the stability of spent fuel under disposal conditions. In oxidising condi-tions, oxidation of U(IV) to a considera-bly more soluble state U(VI) may occur.

The tests regarding the reduction of U(VI) by Fe(II) in NaCl and NaHCO3 solutions (WR 2008-74) were complet-ed in 2009. The tests were carried out under oxygen-free conditions in a ni-trogen atmosphere. The purpose of the tests was to study the effect of Fe(II) in the solution on the oxidation state of uranium and observe any signs of the

reduction of U(VI). The tests showed that Fe(II) will reduce oxidation state U(VI) to U(IV). The results of solubility tests on uranium under high pH condi-tions and in saline water under reduc-ing conditions (WR 2008-75) were also reported in 2009. The solubility tests indicated that the solubility of uranium increased with increased pH in a 0,01 M NaCl solution.

During 2009, Posiva initiated investi-gations regarding studies related to high fuel burn-up that may be required and will be carried out jointly with its own-ers and the Swedish and Swiss nuclear waste organisations (SKB and Nagra).

Disposal canister

CANISTER DESIGN WORK A number of complementary analyses regarding canister design were conduct-ed during 2009 in order to verify that the technical requirements are met. In these analyses, the initial data used, be-sides the geometric measurement data for the canister, are the physical, me-chanical, metallurgic, thermomechani-cal, chemical and fracture-mechanical

properties of the manufacturing mate-rials. Some of these properties depend on the manufacturing process of the components and, for this reason, the measurement results from manufac-turing tests have been included in the initial data for design analyses. On the other hand, the analyses on crack re-sistance and other technical analyses also set requirements for manufactur-ing, and the fulfilment of the respective specifications must again be verified with measurements and verifications. Requirements, manufacture and the ver-ification of properties with demonstra-tions constitute a chain through which canister performance, qualitative and functional validation and the likely ini-tial state can all be established.

A rock displacement has been shown to be a critical load case for the durabil-ity of the canister insert. Therefore, this constitutes the load case determining the dimensions of the canister insert. The combination of magnitude, veloc-ity and direction of the load determines the maximum crack corresponding to the lowest operating temperature of the canister material allowable in the

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Copper tube manufacture using the pierce and draw method.

design parameters that will not grow to a harmful extent during loading. A safety factor is then determined for the maxi-mum crack size thus determined, taking into account any inaccuracies in calcu-lations, manufacture and crack size as-sessment. The resulting computation-al maximum size of fault is included in the manufacturing specification. NDT methods must be used for material in-tegrity checks after manufacture to as-certain with sufficient reliability that no cracks exceeding this limit are present. Analyses and material studies aimed at establishing the durability of the insert of the canister were conducted in co-operation with SKB during 2009. These analyses and studies are expected to be completed and reported during 2010.

Copper has proved to be such a duc-tile material that excessive crack growth will not occur with any realistically pos-sible size of initial crack. Therefore, the critical factor for this material regard-ing its integrity requirements is cor-rosion resistance. However, the size of existing initial cracks is the design basis for dimensioning the cast iron insert, and rock displacement is the design load case for the canister struc-ture. The breaking resistance of cast iron has been determined in mechanical breaking tests at different temperatures. These durability and crack resistance

analyses will be continued and further revised during 2010.

CANISTER MANUFACTUREPosiva produced a report (POSIVA 2009-03) regarding the current status of development work for the canister manufacturing process. It contains a summary of the development work for canister components and their associ-ated manufacturing tests, a comparison of different manufacturing methods as well as an account of the current situa-tion regarding manufacturing capabili-ties of canister components.

In 2009, Posiva and SKB co-operat-ed in a project for developing the can-ister manufacturing techniques, both with respect to the copper exterior and the interior made of nodular graphite cast iron.

Three different methods are being developed for manufacturing the cop-per exterior of the canister: pierce and draw, extrusion and forging. The pierce and draw method allows the manufac-ture of a copper canister with a bottom, whereas the extrusion and forging meth-ods will produce a copper tube. The copper blanks for canister manufacture are cast in Finland. Two copper blanks were cast by Posiva in 2009 as part of the canister manufacturing method de-velopment work.

In 2009, two copper canisters with bottoms were manufactured in Germany using the pierce and draw method. Three rings and the bottom were cut off from both canisters to analyse their me-chanical properties and microstructure. One canister complied with the manu-facturing requirements, but the other had a larger-than-permitted grain size at the bottom and tube wall sections. The results obtained from the manu-facturing tests will be further analysed in early 2010, and the knowledge thus obtained will be utilised in preparations for the next manufacturing tests.

No tubes were extruded in 2009, but the development work for the method continued as further tests were car-ried out using an earlier extruded tube. The extrusion process was also mod-elled, and laboratory-scale extrusion tests were carried out on the basis of this modelling work. The objective was to find, with the help of modelling and extrusion tests, such parameters for the extrusion process that would produce tubes with a more homogenous micro-structure. The results of the modelling and extrusion tests will be utilised in the next full-scale extrusion tests.

One copper tube was forged in Swe-den at the end of 2009. The tube will be examined and some results from this manufacturing test will be availa-

ble in 2010. The grain growth in tubes manufactured us-ing both the extrusion meth-od and the pierce and draw method was studied by vary-ing the temperature and du-ration of heat treatment in the annealing furnace. The results obtained from the studies will be utilised for de-veloping the respective man-ufacturing methods.

The development work for cast iron inserts of disposal canisters continued in Fin-land, Sweden and Germany. Two BWR canister inserts were cast in Finland, while one PWR canister insert was cast in Sweden and five in Germany. The BWR canis-ter inserts are required for

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nuclear waste produced in the plants now in operation in Olkiluoto, while the PWR canister is similar to the EPR can-ister that will be required for disposal of spent fuel produced at the OL3 plant. Of the two BWR canister inserts cast in Finland, one complied with the manu-facturing requirements regarding mate-rial properties, mechanical properties and the degree of formation of graph-ite nodules, but the channels for spent fuel, formed in the casting process, were twisted and molten iron had en-tered the fuel channels in both castings. Therefore, neither insert complied with the manufacturing requirements in all respects. One PWR canister insert was cast in Sweden. The examination of the insert has not been completed yet, but the preliminary results indicate that the material properties and geometry seem to be compliant with the requirements. Five PWR canister inserts were cast in Germany. The first one failed. The oth-ers complied with the requirements re-garding the straightness of fuel chan-nels. Three inserts had good mechani-cal properties and microstructures. The examination of the last cast insert has not yet been completed.

CANISTER SEALINGThe development work for the canister sealing method concentrated in 2009 on the final reporting of results from the series of test welds made in the previ-ous year and on the development work planned on the basis of these results. The demonstration series and its results are discussed in closer detail below in the section entitled Canister demonstra-tion project EB-DEMO.

The preliminary quality requirements for welds have been produced, and they will be reported in the summary report for welding development work in early 2010. The studies on Electron Beam Welding (EBW) have continued at the Department of Materials Science of the Tampere University of Technology. These studies concentrate on producing welds free of defects and their proper-ties. The results will primarily be used for optimising the welding process. The preliminary results indicate that the quality of cover sealing welds is

reasonably good; the smallest dimen-sion of solid material in individual welds has been at least 43 mm and the mini-mum material thickness is 35 mm in all canister welds. The minimum material thickness must be at least 40 mm in 90 % of canister welds. However, the weld penetration is unnecessarily deep, causing deformation and thus also re-sidual stresses.

Two canister lid sealing weld tests were conducted in early 2009 in com-pliance with the preliminary welding in-structions developed earlier. These tests were a continuation of the welding pa-rameters optimization process initiated in 2007, and they were also made for the purpose of establishing a suitable win-dow for these parameters. The process of analysing the non-destructive tests carried out on these test welds is in progress. The destructive tests of these lid welds will being in 2010.

The report of the residual stress test measurements initiated in 2006 was completed in 2009. The stresses meas-ured in EBW welds were higher than expected. However, the measurement methods used provide too conservative results compared with reality. There-fore, the measurement results will be re-analysed using more accurate mate-rial models. In order to establish these material models, a study was initiated at the Tampere University of Technol-ogy with the objective of establishing the elastic-plastic behaviour of the cop-per and EBW weld used for the disposal canister for the purpose of determining the correction for elasticity. The em-pirical part of the study has been com-pleted, and the report will be produced during 2010.

The welding tests associated with studying the residual stresses in EBW welds began in the spring 2009. During the latter part of the year, the tests were supplemented by welding covers on 890 mm and 450 mm long tubes. The pur-pose of the tests was to establish wheth-er residual stresses can be sufficiently influenced by varying welding param-eters. The temperatures and welding-induced deformations during the weld-ing process were measured. These re-sults will be used for verification of the

numerical modelling of the welds. The numerical modelling of welding-induced deformations and residual stress will continue in 2010. The welded lids can later be used for the possible tests on the stress-releasing annealing process.

The earlier tested preliminary welding instructions were deployed in all weld-ing tests. The instructions have been found to be functioning well and easy to apply. Tests on radius measuring instru-ments have been carried out with the objective of adjusting the EBW equip-ment. The measuring instruments allow for documenting the properties of the electron beam and verifying the quality of radius. As a result, the reproducibility of the system can be further improved. The work for producing instructions and their inclusion in the preliminary weld-ing instructions began in 2009 in prep-aration for introducing the measuring instrument to production use.

Another focus area in the canister sealing process was that of increasing the depth of knowledge in the Friction Stir Welding (FSW) method patented by SKB and accumulation of related ex-perience by carrying out FSW lid welds at SKB’s canister welding laboratory in Oskarshamn. One lid was welded to a 250 mm long tube in the spring 2009. After that, the weld was subjected to NDT by SKB. The destructive tests in the project will continue in early 2010 when the final report on these tests will also be produced. The tests have allowed Posiva to gain experience concerning the feasibility of the FSW method and equipment while the Finnish level of ex-pertise in weld research has also been considerably improved.

CANISTER INSPECTIONSA co-operation agreement on inspection activities was signed in 2009 between SKB and Posiva. Within the framework of the agreement, the reliability of in-spection procedures will be assessed in the NDT Reliability IV/V project that mainly concentrates on studying the reliability of inspections carried out by automatic mechanisms, as well as on the influence of human factors on in-spections. It was found in the earlier NDT Reliability II/III project that faults

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Installation of the canister tube on the rotary table of the welding chamber for a welding test.

can be readily detected using US tech-niques but the inspection system has to be evaluated in cases where the orienta-tion of the fault is unfavourable for de-tection. A qualification procedure com-pliant with the recommendations of the ENIQ (European Network for Inspection Qualification) was also analysed in the project. On the basis of these results, the NDT reliability IV/V project will con-centrate on the assessment of certain parameters (such as those associated with inspection instructions and faults to be detected).

The work of compiling lists of faults found in all canister components and welds has been initiated for the purpose of developing the inspection proce-dures. This work will be supplemented by metallographic tests on the detected fault indications. The reliability of the NDT methods applied will be assessed, in part, on the basis of these results. This work will continue in 2010.

Four copper tubes were inspected in 2009 using US and eddy current testing methods and visual inspections. The inspections revealed a few surface de-fects, mainly in the eddy current tests and visual inspections. The depths of these faults are still being analysed, and the work will continue in 2010. The eddy current testing technique for cop-per tubes has been developed to detect any faults on or close to the surface. The process of visual inspection of copper components has been further devel-oped, and the detection capabilities of the method will be assessed in 2010.

The technique for analysing weld in-spection results has been developed with the main objective of detecting faults, but also for the purpose of deter-mining the size of faults using mainly the US, eddy current and X-ray meth-ods. A Probability of Detection (POD) curve was calculated for the X-ray meth-od used on the basis of measurements. The POD curve allows for the assess-ment of the smallest radial defect de-tectable with a dimension of about 1 mm. This work will continue in future years, and the goal is to develop simi-lar assessment methods for different methods (US, eddy current and visual inspection). The work in 2010 and 2011

will concentrate on assessing the proc-ess of determining the fault dimensions.

Welds produced with the friction stir welding method were also inspected during 2009 using US and eddy current methods. The inspections produced certain fault indications in areas where welding parameters had been adjust-ed well outside the optimal parameter range. Fault indications were received both at the root of the weld and close to its surface.

Preliminary instructions for US in-spection of the cast-iron insert were pro-duced. The feasibility of the instructions was tested by inspecting two full-size inserts, and the principle of continual improvement will be applied to rectify

any defects as experience is accumulat-ed. The inspections of inserts revealed certain types of faults, primarily close to the outer surface. The measurement results of faults present close to the surface will be studied using metallo-graphic methods, and their origin will be determined. In addition, one clear fault indication was received close to the bot-tom of one insert, and the defect could be identified as an air bubble of about 20 x 20 x 30 mm in size. A report has been produced regarding the inspection techniques for welds and components, and it will be published during the first half of 2010. The report will discuss the methods used for inspecting the welds and the components.

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CANISTER DEMONSTRATION PROJECT EB-DEMODuring 2007–2008, Posiva imple-mented the EB-DEMO project aimed at demonstrating the actual standard of canister sealing and seal inspection technology prevailing in the company at that time.

The parameters for the welding proc-ess were chosen on the basis of results obtained from earlier welding tests, and they were not altered during the series of tests conducted even though the tests involved welding three sets of four lid welds each. All welds in the first set had plenty of defects bad enough to cause rejection; the second only had a few, while all welds in the third set were acceptable. It is obvious that the defects causing rejection were not caused by minor disturbances to the welding proc-ess. Instead, the impurities deposited on the test pieces to be welded caused a number of welding faults, and the number of these faults decreased when the quality and cleanliness of the pieces was brought up to the standard required for EB welding. Metal sheets were also welded in conjunction with the dem-onstration. These welds confirmed the opinion that the quality flaws detected in the cover welds during the demonstra-tion were to do with the surface quality of components, not with the actual EB welding process.

The final report was produced in 2009. It states that acceptable welds can be produced on the copper shells of canisters using the current competence

in EB welding and NDT techniques, and that their acceptable quality can be reli-ably verified.

Bentonite buffer

The development work for bentonite buffer has continued in line with the development programme produced by Posiva. The work has consisted of the bentonite buffer design work and stud-ying its associated parameters as well as development of the manufacturing and installation processes for bentonite blocks.

The requirements concerning the buffer have been compiled as a design basis. They have been used as the ba-sis for assessing and updating the ref-erence plan produced earlier for the buffer. Development work for the buff-er has been initiated. It involves study-ing alternative solutions for parts of the buffer structure.

Studies have been initiated for ob-taining the input values for the plan-ning. They involve studies on how the buffer blocks start swelling when wet-ted with water in conjunction with their installation, as well as studies on fill-ing the space between the bedrock and buffer blocks using different materials.

The development work for buffer block manufacture has included studies on the suitability of isostatic compres-sion methods for the manufacture of large bentonite blocks. The feasibility of manufacturing parameters has been studied and development work for the

mould structure has been continued by the small-scale manufacture of test blocks. The results obtained have re-sulted in the decision to manufacture medium-sized (35 % of full-scale blocks) and large (70 %) bentonite blocks. The isostatic compression method can be used to manufacture several blocks at time. Pressing plants of sufficient size have been sought in this connection to enable the manufacture of full-scale blocks.

The development work for bentonite buffer installation techniques has in-volved testing the impact that the size of blocks has on their ease of installa-tion. The test results have also been used as the basis for investigating the functionality of installation equipment and the effect of deviations in the dep-osition hole on the installation clear-ances required. The installation tests were carried out using full-scale objects. Both small and large blocks were used. The small blocks weighed 35 kg and they were laid out to form ring-shaped and cylindrical blocks of full size which were then installed in one package. The large blocks were tubular and cylindrical blocks with a maximum weight of 5,000 kg. The material used for the blocks was a concrete mix with the same weight and surface quality as bentonite blocks. A full-scale deposition hole of modular construction was manufactured of steel. Its parameters can be adjusted to corre-spond to the dimensions and tolerances of holes drilled in the bedrock.

Method developed by Posiva for determining the location of the close corner of the channel in the insert using phased US techniques.

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Bentonite blocksproduced by theisostatic compression method at the VTTresearch laboratory.

Backfilling of deposition tunnels and closure of the facilities

The most substantial operation during 2009 was that of preparing the backfill plan for deposition tunnels and report-ing the work carried out during the TKS period approaching its completion. The plan is based on pre-compacted blocks and side pellets as well as a floor level-ling layer, and the quantities of differ-ent components involved have been revised from the previous plan. The re-quirements have also been worked on with a view to developing the deposition tunnel excavation process. The final re-port of the Baclo programme, produced jointly with SKB and published during 2009, was used as the basis for report-ing. A three-year programme is under preparation for the purpose of verifying the backfilling material plan; part of this work will be implemented jointly with SKB.

During the year, tests were carried out at the Äspö bentonite laboratory that form the basis for studying the contribution of tunnel seepage waters to the behaviour of backfill materials. Background information will also be obtained in this connection regarding the need to restrict the flow of seepage waters in the tunnels.

Regarding the production of backfill material, preliminary tests for the serial production use of the uniaxial compres-sion method have been initiated. The details studied in these tests include the impacts of pressure, water content and temperature on the end result and block quality.

Regarding the installation of backfill material, preliminary tests have been carried out for the 40:60 mix of ben-tonite and crushed rock to be used for floor levelling. The results will help plan the actual floor installation tests. The installation of blocks using the modular installation method has been planned, and the results of this work were uti-lised when producing the plan for back-fill material. The preliminary testing of the backfill material plan regarding its different components will take place in 2010, after which the actual implemen-tation planning for different prototypes will commence.

Tests have been carried out to study the chemical composition of different backfill materials, particularly that of alternative materials. Laboratory-scale results have been obtained of the self-healing capability of the backfill mate-rial, and these results will be utilised for, among other things, the assess-

ment of alternative materials. The small-scale concrete tunnel tests have been reported and the erosion properties of different materials (Blocks of Friedland clay and blocks of 40:60 bentonite and crushed rock mixture) compared in a situation where the tunnel has been filled as full of blocks as possible. The tests will continue in 2010.

The principal plan for the plugs to be inserted at tunnel mouths was pub-lished in early 2009. The preliminary plan for the closure of other facilities will not be completed before 2010 because all the basic information for the proc-ess has not been obtained yet. Posiva is also monitoring the closure-related project of URL, the research laboratory of AECL of Canada where two combina-tion plugs (concrete structure combined with a mixture of bentonite and rock ag-gregate) are constructed at a depth of several hundred metres down the shaft.

Bedrock characteristics at the disposal site

INVESTIGATIONS CARRIED OUT FROM GROUND SURFACE Three new boreholes, OL-KR51, OL-KR52 and OL-KR53, were drilled in the eastern part of the Olkiluoto site in 2009. The

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Locations of boreholes OL-KR1–OL-KR53.

borehole depths were 650 m, 427 m and 300 m, respectively. Boreholes OL-KR51 and OL-KR52 were utilised for continu-ing the general characterisation work of the eastern area with respect to the geological, hydrogeological and hydro- geochemical properties of the bedrock. Borehole OL-KR53 was primarily drilled for the purpose of studying the eastern lineament bounding the island of Olkiluoto. The research data obtained from the boreholes is required for de-signing the repository facilities. Of the borehole studies, flow measurements and geophysical standard measure-ments were already completed during 2009. The chemical analyses of ground-water samples will be carried out in 2010.

One investigation trench, OL-TK17, was excavated in the eastern part of the site during 2009. The trench runs almost parallel to borehole OL-KR51 in the northern part of its ground level projection. Geological mapping of the exposed rock surface was produced. Soil samples were also taken from the trench at 25-metre intervals. The results

obtained from the trench will be used for updating the geological model. The da-ta obtained from soil samples will also be utilised for the soil thickness model.

In 2009, the borehole studies con-centrated on the eastern part of the site. Geophysical measurements in the bore-holes continued as in previous years. In addition to geophysical standard measurements, all boreholes drilled in 2008 and 2009 were investigated using a video camera. In addition, measure-ments were carried out for establishing the electrical conductivity of the bed-rock. The geophysical results are used as complementary information when updating both the geological and hydr-ogeological site model.

Hydrogeological studies in the survey site continued by measurements of flow characteristics in the bedrock from holes drilled in the eastern survey area. The measurements were taken using both the Posiva Flow Log and a HTU (Hydraulic Testing Unit). The HTU measurements concentrated on the depth range of 300–600 metres. Transverse

flow measurements continued as part of the recharge test monitoring meas-urements in short bedrock holes OL-PP66–OL-PP69 drilled in the vicinity of boreholes OL-KR14–OL-KR18. The measurements were taken to establish the effect of pumping on the natural state of flow prevailing in the boreholes. The results will be reported in 2010, and they will be used for producing ground-water flow models and as basic informa-tion for planning other studies, such as water sampling programmes.

The sampling of groundwater from deep boreholes concentrated on bore-holes drilled in 2008. The work concen-trated in particular on trying to obtain samples of saline groundwater below a depth of 400 m and from fractures of low water conductivity. Sampling has been continued to establish the locations where saline groundwater is present. Microbes and gases dissolved in groundwater were another area of in-terest. Water sampling from the bore-hole drilled under the seabed (OL-KR47) was completed. The recharge test start-

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ed in 2008 is continuing. The chemical changes possibly occurring in ground-water have been monitored through sampling campaigns. The results for the first year of testing will be report-ed during the spring 2010. The results will be used for updating the hydrogeo-chemical model.

STUDIES CONDUCTED IN ONKALO Research was carried out in ONKALO during 2009 in order to establish the excavation-induced changes and the properties of the bedrock surrounding ONKALO. Research data was produced during the year on the quality and pro- perties of the bedrock as well as on its hydrogeological and hydrochemi-cal properties. The research data was used inter alia for planning grouting and reinforcement operations and for further specification of different mod-els describing the properties of the bed-rock. Most of the studies were conduct-ed while excavation operations were in progress; excavation was only suspended when pilot boreholes were being drilled.

The research activities carried out during excavation operations included mapping, probing hole measurements, drilling studies, groundwater sampling, flow measurements and rock-mechan-ical measurements. The work for map-ping geological characteristics and seep-age water continued as the excavation work progressed. During the early phases of geological mapping, information is collected for the immediate needs of the excavation and planning opera-tions, and later when excavation has progressed further, mapping is done for documenting the types of rock, bedrock quality, detailed geological characteris-tics and seepage water volumes. By the end of 2009, systematic geological map-ping had progressed to chainage 3960.

Measuring weirs were utilised for seepage water measurements; they are used for metering the volumes of accu-mulated water as well as its chemical properties (pH, EC).

Probe holes are drilled in the tun-nel profile at approximately 20-metre intervals. Measurements related to in-gress of groundwater, water loss and flow rates are regularly performed in the

holes. The total exit flow rate of the hole is also measured in connection with wa-ter loss. The flow rates of probe holes will be measured if the hole output ex-ceeds 30 ml/min. All flow measurement results obtained from ONKALO will be utilised when producing a more detailed hydrogeological model of the Olkiluoto bedrock.

During 2009, pilot boreholes ONK-PH10 and ONK-PH11 were drilled in the access tunnel at chainages 3459 and 3922. The boreholes were about 180 m and 130 m long. The excavation work was suspended for the duration of drilling the pilot holes and carrying out the associated hole studies. Nor-mally, the pilot boreholes are subjected to geophysical measurements included in the standard regime, optical imaging, flow logging, water loss tests and water sampling. For borehole ONK-PH11, the tests were supplemented with acoustic imaging, and the water loss measure-ments were taken using Posiva’s own equipment.

In 2009, the pilot and probing hole measurements were supplemented by flow logging in new groundwater sta-tions drilled in ONKALO, in shaft grout-ing holes (mainly for the purpose of planning grouting work) and at chain-age 3620 in connection with EDZ studies.

The measurements of state of rock stress continued as in previous years. The measurements began with new pre-liminary tests for checking the opera-tion of the measurement instrument in the conditions prevailing in the shaft at a depth of 265 metres. The purpose of the method is to measure the second-ary stress field surrounding the quarried space. This allows for computing the in situ state of stress prevailing in the area. The tests were carried out by first drill-ing out strain gauges installed in the bedrock and the LVDT sensor cells later installed in the same locations. The rock samples with strain gauges were also tested in the biaxial cell. The method was utilised in late 2009 for determin-ing the state of stress in research facility 3 (EDZ investigation niche).

In addition to the above, the work for determining the state of rock stress continued with convergence measure-

ments at the lower ends of shafts. They were carried out at inlet air shaft levels -180 m and -290 m. The purpose of the measurements is to monitor the rock deformation caused by raise boring. Several factors, including the shape of the tunnel and the penetration point of the shaft, cause interference to the measurements. An optical fibre meas-urement system was installed around the theoretical profile of the shaft at the end of the inlet air shaft at level -180 m to supplement the conventional con-vergence measurements. The purpose of this instrumentation was to moni-tor the deformation of the shaft during raise boring. Temperature variations and deposition of airborne dust on the optical fibres proved problematic for the instrumentation. The measurement re-sults did not allow the determination of the degree of deformation.

The monitoring of bedrock tempera-ture changes continued in the first re-search facility (PL1475). The tempera-ture monitoring system installed in the autumn 2008 has now operated sys-tematically after the malfunctions ob-served in the spring 2009. The purpose of these measurements is to monitor the transfer of heat into the bedrock as the temperature of the quarried rock changes.

The planning of investigation niche studies continued in 2009, and some of the studies were initiated. The niche studies carried out in ONKALO include: rock spalling studies (POSE), hydroge-ological interaction test (HYDCO), sul-phate reduction test (SURE), and the test for establishing the retention prop-erties of the bedrock (REPRO). Of these, the HYDCO and REPRO tests are at the planning stage, and work in the tunnel will commence during 2010. The first research holes for the SURE test were drilled, and the basic studies regarding them were completed. The study plan for POSE is also ready and work in the tunnel has began.

MODELLING WORKThe Olkiluoto Modelling Task Force (OMTF) coordinates the modelling work of the Olkiluoto. The work of the OMTF involves interpretation and

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modelling work of the different research disciplines (geology, hydrogeology, geo-chemistry and rock mechanics), aimed at complementing the understanding of the site. The output of this work, the description of the disposal site, will be used as basic information for both the designers of the repository and the ana-lyses of long-term safety. The Olkiluoto Site Description 2008, the third succes-sive description of the disposal site, was published in 2009. It includes updated models from all lines of research. The sections below present the key results of each field of research for the round of updating models.

The results of modelling gave no reason to change the opinions regard-ing the suitability the bedrock for geo-logic disposal.

Geological and geophysical modelling The Site Description 2008 published in early 2009 presented version 1.1 of the geological model. The model was up-dated to version 2.0 during 2009. This model will be presented as a working report in early 2010 and used as the ba-sis for the following round of site mod-elling work. The statistical model (the so-called DFN model) of bedrock frac-tures in Olkiluoto was also reported in 2009. Work for updating it on the basis of new mapping material also started during the year.

Geological modelling comprises four parts: the ductile deformation model, rock type model, alteration model and brittle deformation model. The ductile deformation model describes the plas-tic deformations taking place in the bedrock. The properties of throughout orientation of the bedrock was analysed as the most important of these. The ori-entation data, together with mapping re-sults of exposed bedrock and drill core surveys, is utilised when modelling the rock type distribution in the Olkiluoto bedrock. The purpose of the metamor-phosis model is to use borehole data to produce a three-dimensional model of the hydrothermal alteration observed in the bedrock. The current understand-ing is that this phenomenon that has, among other things, produced clay min-erals in the bedrock, was mainly created

about 1.6 billion years ago as a result of penetration of rapakivi granite into the bedrock of the nearby areas. The brittle deformation model, in turn, tries to pro-duce a very detailed description of the brittle fault and fracture zones present in the bedrock. According to current knowledge, the faults in the Olkiluoto area were originally so-called overthrow faults that were re-activated by later oc-currences in the bedrock hundreds of millions of years ago.

The results of modelling will be as-sessed using the prognosis and mate-rialisation analyses introduced earlier where the predicted characteristics are compared with the geological charac-teristics actually observed in ONKALO. The results from this comparison work will help better target the research and modelling methods when assessing the suitability of the disposal bedrock. As in the geological site model published early in the year (version 1.1), the up-date now carried out is also based on detailed data obtained from drill cores regarding ductile characteristics, types of rock, degree of alteration and brittle zones. The focus of the new drill core material is in the eastern part of the is-land, which allows the production of a more reliable geological description of this area as well.

In addition to geological data, the modelling also extensively utilised geo-physical data. Many geophysical meth-ods are particularly suitable for model-ling fragmented bedrock zones. Geo-physical methods were used to obtain information about the distribution of zones between boreholes and outside the survey site. New data has also been used to further specify the geometry of the zones. Other partial models of the geological model were also developed during 2009 on the basis of new in-formation. The geological model will continue to form the basis for other models.

An updated model (version 1.1) of the ONKALO area was published in 2009. In this model, the geological and geophysical modelling work was integrated and the updated models were supplemented with hydrogeo-logical data.

Hydrogeological modelling The focal areas of surface hydrogeo-logical modelling in Olkiluoto for 2009 were the assessment of the impact of seepage waters in ONKALO and the modelling of the basic state of the re-charge test. The main objective of the calculations made using the surface hydrogeological model of Olkiluoto was to assess the impact of seepage water volumes in ONKALO on the level of groundwater in the soil layers and on pressure heads in short boreholes in particular, as well as to assess how wa-ters seeping into ONKALO affect the water balance of the entire island and what the origin of these seepage wa-ters is. The model calculations were carried out using several different val-ues for seepage water flows and by allo-cating the seepage waters separately to the tunnel and shafts of ONKALO. The modelling results were used as back-ground data when updating the limit values for seepage water in ONKALO.

The results of modelling indicate that the seepage waters in ONKALO lower the groundwater levels, particu-larly during years of less rainfall. The results show that the groundwater table in the surroundings of ONKALO may, for short periods, be below the seawa-ter level if the seepage water flows to ONKALO at a rate of 180 litres/minute or more. When the total seepage wa-ter flow rates are below this value, the groundwater table stays above sea lev-el. The calculated maximum drop in groundwater table is about 5.5 m when the total flow of seepage water is 140 li-tres/min or less. The calculations show that the impact of ONKALO on both the thickness of the unsaturated layer and the extent of the affected area clearly in-creases when the seepage water volume is 180 litres/min or more.

A version of the surface hydrological model was produced in 2009 and it can be used for analysing the results of the recharge test. The first version of the model only described the main zones conducting water. The measure-ments and the model both show that local zones of high water conductivity are very important in the recharge test scale, which is why the model will be

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further specified regarding the descrip-tion of zones during 2010.

The updated hydrogeological struc-tural and flow model was reported in Site Description 2008. After that, hydr-ogeological modelling work has been done in connection with analyses of long-term safety and in particular as support for the development work of rock suitability criteria.

For the rock suitability criteria devel-opment work, a modelling-based esti-mate was produced in 2009 on how the seepage waters entering the repository will be distributed between different deposition tunnels. In the basic scenar-io, the average distance between bed-rock fractures with a water conductivity in excess of 10-11 m2/s is 23 metres. How-ever, the distances between these bed-rock fractures with very low water con-ductivity vary a great deal. The results of the estimation work are based on analyses that do not take into account the possibility of placing the deposition holes in bedrock sections with minimal fragmentation, chosen on the basis of pilot borehole data and later verified in the actual deposition holes. On the oth-er hand, the model assessment shows that the long fractures intersecting the repository facilities have little impact on the distribution of seepage waters.

In connection with the bedrock suit-ability criteria, the rise or upconing of saline water present much deeper in-side the bedrock than the repository was also assessed in 2009. In the basic sce-nario, the salinity of groundwater at the disposal depth would increase from its original value (16 g/l) to approximately 40 g/l during one hundred years of rock construction work.

Hydrogeochemical modelling The updated hydrogeological ground-water model was reported in Site De-scription 2008. Much more is known about the chemical composition of groundwaters in fractures of low water conductivity now than during the previ-ous version of the model. The increase in knowledge on microbes and isotopes has also improved the understanding of factors controlling the composition of infiltrating groundwater. On the basis

of observations made in connection with updating the model, the research activities of future years will be directed at studying the processes significant to long-term safety. These include the studies on the processes affecting the sulphide quantities, the origin of meth-ane dissolved in the groundwater as well as the relationship between groundwa-ters and matrix waters.

During the autumn 2009, the hydro-geochemical modelling and interpreta-tion work focused on preparing back-ground material for the next round of modelling. An extensive process of as-sessing the representativeness of data on the electrical conductivity of ground-water began in the autumn. The objec-tive of this work is to select representa-tive measurement data for the update of the groundwater salinity model sched-uled for the summer 2010. The work for interpreting the isotope results obtained from the entire groundwater material al-so began. This work will be completed in the spring 2010. The first trial mod-els for establishing the origin of meth-ane have already been produced, and this work will be reported early in 2010. Reactive transport modelling work has also been carried out for the recharge test. The results of modelling are in the process of being reported.

Rock-mechanical modelling The rock-mechanical block model was reported in the autumn 2009. At the same time, modelling work continued using new data and structural interpre-tations. The input data used for model-ling included that obtained from rock-mechanical studies carried out in bore-holes and ONKALO, geological map-ping and geophysical measurements. The end results of modelling include a description of the bedrock quality and the mechanical parameters of brittle structures and bedrock with few frac-tures as well as the spatial distribution of rock strength and its state of rock stress. Rock-mechanical analyses were carried out during 2009 for the purpose of predicting the degree of rock damage in the demo facilities and technical fa-cilities of ONKALO. The analyses were carried out using a 3D edge element

program (Examine 3D), taking into ac-count the measured deviations of bed-rock stress and rock strength values. The result was a forecast of the proba-bility of bedrock damage and its depth. The forecasts will be reported in 2010.

In addition to the above, phenomena occurring and possibly observed in the vicinity of the rock-mechanical research facility were simulated. Due to moving the research facility to another location, the simulation will be repeated during 2010 when the latest interpretation of stress data from the research depth will be available. The material and the simu-lation will be reported in 2010.

Rock Suitability Criteria The Rock Suitability Criteria (RSC) pro-gramme defines the suitability criteria for the bedrock and the suitable volu-mes of bedrock for the needs of lay-out design and disposal operations. The preliminary, or RSC-I, criteria were published as a Posiva Working Report in the spring 2009 (TR 2009-29). The testing of RSC-I criteria began with pi-lot borehole ONK-PH10 drilled in the access tunnel of ONKALO. The tests will be reported in early 2010. In order to verify the test results, geochemical samples and samples related to stud-ies of structural geology were taken from ONKALO for analysis. A Master’s Thesis on local phenomena associated with rock faults was also produced. The development work for RSC-II criteria be-gan in late autumn 2009 on the basis of test results obtained for RSC-I criteria. The development work will, in part, take place in co-operation with SKB.

The plan for the RSC programme was updated towards the end of the year, particularly with respect to the coordi-nation of planning and construction work. The update also emphasised the importance of developing the quality management system of the entire pro-gramme. The demonstration of criteria of the RSC programme begins in ONKA-LO at the disposal depth in the so-called demonstration tunnel in late 2010. The planning work for the RSC programme demonstration has begun.

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The facility complex consists of an encapsulation plant to be constructed at ground level, other auxiliary buildings and structures at ground level and the underground repository. The construction work for the encapsulation plant and re-pository will begin when the construction licence has been granted. The operations of the facility are scheduled to start in 2020 after the operating licence has been granted.

The spent fuel brought from the interim storage is pack-aged into canisters in the encapsulation plant and trans-ferred to the repository in a lift. The current plans involve

excavation the repository facilities on one level at -420 m. Access to the underground facilities is through the access tunnel and shafts. Deposition holes will be drilled in the floors of the deposition tunnels for inserting the canisters. The canisters will be completely surrounded by bentonite blocks that will swell considerably when becoming wet. The facilities will be expanded as the disposal operations progress by excavation more deposition and central tunnels. The planning and design work for the encapsulation plant and repository progresses in three-year periods.

Design and planning of the encapsulation plant and repository

Encapsulation plant

The draft design phase of the encapsu-lation plant ended at the end of 2009 with a report on the status of planning at that stage. The primary alternative is still an encapsulation plant connected to the repository by a canister shaft.

The equipment design work for the encapsulation plant has produced plans for the canister weld inspection station, the fuel transport container transfer trol-ley and the docking station. Equipment for X-ray, US, eddy current and visual

inspection of the weld are foreseen for the inspection station. The different methods will complement each other and help ensure that the weld complies with the prescribed requirements. The fuel transport container transfer trol-ley operates in the transport container transfer corridor and is capable of mov-ing transport containers of different sizes to the docking station of the fuel processing chamber.

The equipment plans now completed supplement the equipment plans for the encapsulation plant so that equipment

plans of at least a preliminary level are available for all main equipment in the fuel encapsulation process. These pre-liminary plans form a comprehensive basis for further equipment design work aimed at designing and producing pro-totype equipment.

Draft system descriptions were pro-duced for certain encapsulation plant systems as part of the preliminary li-censing documentation submitted to the authorities for their perusal. The results of their assessment will be tak-en into account when the final system

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Computer image of the disposal canister weld inspection station.

2009 layout plan for the repository.

descriptions are submitted in connec-tion with the construction licence app-lication.

Repository

The outline design phase of the reposi-tory ended at the end of 2009 with a report on the status of planning. The layout of repository facilities was up-dated in the plan on the basis of the latest bedrock data. In addition, the lay-out determining features of the bedrock

structure, determined as part of the RSC programme, were now used for layout design for the first time. The design and planning work for the repository has been carried out in close co-opera-tion with the implementation planning work for ONKALO in order to ensure the compatibility of facilities.

The repository design is based on an alternative where the canisters are trans-ported via the canister shafts in a can-ister lift from the encapsulation plant to the disposal level. The plan involves

a total of five shafts, three of which will be implemented as part of ONKALO and two later.

The updated plan is for an approx-imate fuel quantity of 5,500 tU. This quantity will cover the spent fuel pro-duced by the plants currently in opera-tion or under construction during their planned operating life. The repository facilities are laid out on one level at a depth of 400�420 metres. The plan also includes an updated description of the implementation, from its phasing to different expansion phases.

The repository also includes the buildings at ground level assisting in its operations. Of these, the ventilation building and lift building are among the most important. The ventilation build-ing feeds fresh intake air to the entire repository and removes the exhaust air from underground facilities. The ventila-tion building is connected to all ventila-tion shafts. The lifting equipment build-ing is located above the personnel shaft, and it houses the machinery of the lift intended for all personnel transports in the facility. The implementation plan-ning for the buildings has already be-gun, and the buildings will be, in part, built already in connection with the construction of ONKALO.

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Production of evidence in support of the safety case

Plan for the production of evidence in support of the Safety Case

In keeping with the schedule confirmed by the Ministry of Trade and Industry in 2003, Posiva is making preparations for submitting its application for the con-struction licence for an encapsulation plant and repository for spent nuclear fuel towards the end of 2012. In the li-cence application, the long-term safety of disposal is discussed in the so-called safety case. According to an internation-ally adopted definition, “safety case” refers to all the technical-scientific docu-mentation, analyses, observations, tests and other evidence that are used to sub-stantiate the safety of disposal and the reliability of the assessments thereof. The main reports included in the safety case and their foreseen schedule until 2012 are shown in the Safety Case Plan 2008 (POSIVA 2008-05).

The major tasks in 2009 included the work for compiling the Models and Da-ta report. The report will be completed in 2010. In addition, work was done in 2009 for producing the Interim Sum-mary Report of the Safety Case – 2009 that will also be completed in 2010. This Interim Summary Report outlines the current status of Posiva’s safety case regarding the disposal of spent fuel in the Olkiluoto bedrock using a disposal method based on the KBS-3 principle.

The work for producing the FEP (Features, Events and Processes) da-tabase report, process report and sce-nario formation report began in 2009. The process report presents a descrip-tion of significant features, events and processes (FEP) and the interactions be-tween them. The scenario formation re-port presents the systematic selection of

sequences of events in the disposal site and the repository for scenario analysis.

Performance of release barriers

The technical release barriers are the primary factor ensuring long-term safety in Posiva’s safety concept. The safety of the KBS-3 solution is primarily based on the long-term isolation of radionuclides in disposal canisters, and on techni-cal release barriers ensuring the leak-tightness of these canisters, as well as on natural conditions and processes. The performance studies have concen-trated on establishing the behaviour of the copper canister and the bentonite protecting it, as well as on studying the harmful processes. The studies have been carried out both in interna-tional co-operation – for example, in EU framework programmes and in the Äspö rock laboratory – and also using exclusively Finnish resources. The stud-ies produce input data for future safety assessments and discuss and develop the requirements for planning and de-signing the repository facilities, tunnels, shafts, backfill materials and sealing structures.

The BENTO programme, aimed at developing expertise in the use of ben-tonite, has involved studies related to the technical design and development work of the buffer as well as to reduc-ing the uncertainties associated with the safety case and methods development work in order to develop the necessary routines. Work has been done for de-veloping the mineralogical and chemi-cal characterisation of bentonite and to establish the water saturation process and the properties of bentonite com-pletely saturated with water. Develop-ment work for both the empirical and numerical methods has been carried out

in all areas. The main individual areas for investing resources were: – saturation with water in general,– erosion of buffer materials possibly associated with the early stage of water saturation,– interaction between saturated bentonite and concrete,– interaction between saturated bentonite and iron,– cementation of saturated bentonite caused by salts and silicates,– the effect of high salinity on the swelling pressure of saturated bentonite,– repeated freezing and subsequent thawing of saturated bentonite, and – erosion of buffer materials in condi- tions prevailing after an ice age as a result of dilute melt water possibly entering the repository facilities.

Another goal of the BENTO pro-gramme is to increase the competence and resources of bentonite-related R&D work, as well as the research instrumen-tation used for the purpose. Develop-ment work in these areas took place in 2009.

During 2009, Posiva participated in several international research projects on the behaviour of bentonite, and in the preparatory work of these projects. These included the 7th framework pro-gramme of the EU, entitled FORGE (Fate Of Repository GasEs), the CFM (Colloid Formation and Migration) project by the Grimsel Rock Labora-tory, and the FEBEXe (Collaboration in the Full Scale Engineered Barrier Experi-ment in Crystalline Host Rock), which all began in 2009. In FORGE, Posiva participated in producing a description, based on current knowledge, of the mi-gration of gases inside bentonite. In CFM, Posiva participated in developing

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a method for estimating the degree of erosion in clay caused by dilute waters. The results indicate that the factors lim-iting the phenomenon are independent on the set-up used for the test. The FE-BEXe project continued the monitoring of the long-term test and collection of data from it.

In addition to the above, Posiva has also participated in coordination work in the EBS Task Force for the develop-ment of assessment procedures and modelling tools regarding technical bar-riers. The modelling of test cases carried out in this context has shown that the predictability of THM (Thermo-Hydro-Mechanical) phenomena provided by the different models is very limited in very similar ways. Test cases regarding chemical developments in bentonite were prepared in order to create a com-mon approach.

In 2009, Posiva participated in the ABM (Alternative Buffer Materials) project in progress at Äspö, and which has been running for several years. Its purpose is to study the long-term proc-esses taking place in different bentonite materials in a full-scale test. The first actual samples were obtained for anal-ysis in the spring 2009, and the results will be reported in 2010. In addition, Posiva participated in the Large Scale Gas Injection Test (LASGIT). This test, studying the migration of gases in sat-urated bentonite, has been continued by repeating stages already carried out for the purpose of producing statistical certainty for the results. The first phase of the tests showed that gases migrate in saturated bentonite through predict-able mechanisms.

Posiva participated, in the role of an expert, in an international study of natu-ral analogue, the purpose of which was to accumulate knowledge on the long-term stability of bentonite under high pH conditions. The studies take place in Cyprus. The second phase of the study took place in 2009 and it involved se-lecting the best subjects among the samples analysed in the first phase for the studies to be carried out in the third phase.

SKB and Posiva continued their joint empirical research on the corrosion of

copper under conditions corresponding to those during final disposal. A report (WR 2007-63) was published in 2009 regarding studies conducted in Cana-da and where empirical results were used as the basis for modelling the be-haviour of corrosion potential of cop-per in compacted sulphite-containing bentonite. Further, the work for updat-ing the State of the Art report (Posiva 2002-01) on the corrosion of copper produced in 2002 continued in 2009 in co-operation with SKB. In addition, dur-ing 2009 Posiva and SKB have planned and initiated studies regarding the cor-rosion of copper in water. One of the purposes of these studies is to repeat the tests published by Hultquist and Szakálos in 2008 regarding which a workshop was organised by Kärnavfall-srådet in November 2009. The results of this event will be taken into account when planning further actions. The stress corrosion studies initially sched-uled to start in 2009 were postponed to 2010 due to limitations in the personnel and equipment resources of the labora-tory foreseen to carry out the tests. The work for assessing the long-term safety implications of residual stresses possi-bly present in the EBW welds on copper began in 2009.

The cement studies related to long-term safety continued with Nagra of Switzerland, JAEA of Japan and NDA of Great Britain in the LCS (Long-term Ce-ment Studies) project aimed at studying the interactions of grouting cement with bedrock in situ in Grimsel, Switzerland. The purpose of the laboratory tests con-ducted in support of the field tests is to model the dissolving of cement and its interactions with the bedrock. The first phase of the project ended at the turn of the year 2008–2009, and the work for reporting its results is still in progress. The second phase of the LCS project has began, and it is scheduled to continue during 2009–2013.

In 2009, a study (WR 2009-26) was conducted regarding the stability of silica colloids released from silica sol and their sorption in radionuclides (Eu-152) in saline and low-salinity ground-water simulations. The tests revealed that the salinity of groundwater has a

significant effect on the release and stability of silica colloids. This means that no significant release of silica col-loids from silica sol is expected to take place in the Olkiluoto groundwater con-ditions of moderate or high salinity. However, the possible combined effect of silica and bentonite colloids, as well as the effect of melt waters after an ice age must be taken into account when assessing the significance of colloids. The concentrations of released silica colloids are slightly higher than the natural colloid concentrations deter-mined from groundwater surrounded by granite rocks.

Bedrock as a release barrier

The results calculated by REPCOM soft-ware, used for migration modelling of the surrounding rock areas, were as-sessed in 2009 by comparing them with the results obtained from Gold-Sim modelling. In a conservative case where the model parameters are select-ed by overestimating the resulting radia-tion doses, the results calculated using REPCOM were well in line with those obtained using the GoldSim model. In a more realistic case (in a situation corresponding to less harmful radia-tion effects) that takes into account the limited solubility of radionuclides, the model calculations using REPCOM and the GoldSim model produced different results because the ability of REPCOM to process more realistic situations is limited.

The development work for the ra-dionuclide migration model (MARFA) continued in 2009 in collaboration with SKB. MARFA software allows taking into account limited and unlimited matrix diffusion, equilibrium sorption, longitu-dinal dispersion, radioactive decay and in-growth. The capabilities for process-ing the effect of changes in external con-ditions over a long period of time (land uplift, climate change) on migration routes and the locations where these routes surface were also developed for version 3.3. of the software.

Co-operation in the Task Force for groundwater flow and solute transport at the Äspö Rock Laboratory continued.

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Work on surveying the species of earthworm found in Olkiluoto in the summer 2009. Photo: Marko Nieminen / Faunatica Oy.

The contents and time schedule of the Task 8 package was planned in 2009. The purpose of this package is to study the modelling of bentonite tests.

The spent fuel safety analysis will include an estimate of the behaviour of radionuclides in the geosphere. As part of this estimate, the migration of radionuclides as well as their retention in the rock material and surfaces of bedrock fractures will be analysed. The magnitude of retention of dissolved ra-dionuclides is described by the distri-bution factor. The value of the distribu-tion factor depends on the conditions, which is why the values best describing the distribution in the analysed chemi-cal and physical environments (types of rock and minerals present in Olkiluoto and the composition of its groundwa-ter) are selected for the migration esti-mates. The empirical work for updating the values of these parameters for the most important radionuclides began in 2008, and it continued in keeping with the planned schedule in 2009. The work for reporting its results is still in

progress. The work is scheduled to still continue during 2010.

Biosphere

Biosphere-related work has taken place during 2009, in keeping with the TKS-2006 programme, a separate biosphere work plan (POSIVA 2006-07) and the revised Safety Case (POSIVA 2008-05). The goal of this work was to produce an updated description of the biosphere (POSIVA 2009-02), forecasts for future terrain and ecosystems, as well as ra-dionuclide migration simulations and a dose assessment. Reports of these will be completed in early 2010. Collec-tively, these reports constitute a holistic assessment of the biosphere.

In addition, a project was initiated in 2009 for developing the numerical methods used for estimating the un-certainties associated with the terrain model and land uplift model, while the extensive research project regarding the retention of radionuclides in soil and sediments continued. A research

project of many years, based on auto-matic measurements, was initiated for further specifying the sedimentation conditions in sea areas. The modelling methods were developed particularly by combining the terrain forecasts and ra-dionuclide migration modelling through a more detailed soil and surface hydrol-ogy model.

Posiva has also actively participated in the operations of the international BIOPROTA forum – for example, by heading the joint project for testing the methods for assessing ambient radia-tion levels – which will produce its final report in early 2010. On a regional level, Posiva participated in various projects including the Jokivarressa (By the Riv-erside) and the Muuttuva Selkämeri (Changing Bothnian Sea) projects.

General research

In 2009, Posiva started, in co-operation with SKB and NWMO of Canada, the three-year Greenland Analogy Project (GAP) with the main objective of estab-

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Researchers from the GAP project by the edge of an ice sheet in Greenland.

lishing the effects of the ice sheet on the circulation and chemical properties of groundwater. The results of this project will be required for assessing the safety of disposal deploying the KBS-3 solution in ice age conditions. The results of this project will also help to analyse the degree of realism in the existing ice age models and modelling of groundwater chemistry during an ice age.

Posiva is working with the Finnish Meteorological Institute on an update of the climatic scenario for Olkiluoto. The purpose of this update work is to asses the duration of cold periods (ice ages), i.e. the extent of their impacts in Olkiluoto on a time scale spanning 100,000 years. The update work also takes into account the probability of

such cold periods occurring, as well as any warm periods that may occur. The material accumulated from the climatic scenarios will be utilised for the safety analysis studies concerning Olkiluoto, including the modelling of the forma-tion of permafrost and the evolution of ground level hydrology, biosphere and groundwaters deep inside the bedrock.

One of the objectives of the Geo-Satakunta project was to produce a model describing the structure of the Kokemäenjoki River and its estuary, maps of suitability for construction and information on brittle deformation in the Satakunta region. The project began in 2000 and continued in 2008 under the title InnoGeo. The concluding semi-

nar of the project was organised in April 2009, and the final report will be com-pleted during 2010.

Posiva is participating in the PAMI-NA (Performance Assessment Method-ologies in Application to Guide the De-velopment of the Safety Case) project belonging to the 6th framework pro-gramme of the EU; it is concerned with the development of methodology for safety analyses and dealing with its uncertainties. As part of this project, Posiva participated in a task package aimed at compiling a collection of State of the Art style regarding the handling of uncertainties. The project ended in 2009 and the results will be reported during 2010.

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Development of the horizontal disposal solution

Illustration of the KBS-3H solution principle.

In parallel with the vertical disposal solution (KBS-3V) now constituting Po-siva’s reference solution, the horizontal disposal solution (KBS-3H) has been developed jointly with SKB. The deci-sion to continue developing the hori-zontal disposal solution was taken in the spring 2008, and a new project en-titled Täydentävä tutkimusvaihe (Sup-plementary research phase) was ini-tiated with SKB for 2008–2010. This research phase will consist of solving problems identified in the plans to date as well as preparing a plan for initiat-ing the next phase. The next phase for years 2011–2014 will include full-scale testing of system components, prepa-ration of the final technical plan as well as the production of a safety case for Olkiluoto and Forsmark in Sweden. The goal to be achieved by 2014 is that the information obtained should allow a detailed comparison of the 3V and 3H alternatives. This would then form the basis for making the decision regarding full-scale testing of the entire system, either for the 3V or the 3H alternative.

The objective of safety studies con-ducted during the current phase of the

project is to accumulate sufficient infor-mation on the effects of iron, titanium and copper on bentonite to a allow making, with the support of technical studies, a holistic assessment of which material should be used for the protec-tive cylinder of the supercontainer. The tests for studying the interactions be-tween protective cylinder material and bentonite have concentrated on the physical, mineralogical and chemical properties of bentonite. Another impor-tant part of the work is that of determin-ing the long-term safety requirements of the horizontal disposal solution.

The main goal of planning during the current project phase is to resolve the questions identified as important during the previous phase of the study. Many of these questions are related to the buffer and its behavior. Of the design alternatives, DAWE (Drainage, Artificial Watering and Air Evacuation) and STC (Semi Tight Compartment), the latter has been deemed to be asso-ciated with serious uncertainties. This is why the main focus of the project is on the DAWE design alternative, and the important buffer issues associated

with it have been studied in laboratory conditions by modelling and/or in theo-retical analyses. The buffer-related de-sign objective is to produce detailed plans for the buffer to be inserted be-tween the spacer plug and the super-container. In the DAWE design alterna-tive for horizontal disposal, an artificial wetting method is used to ensure the wetting and swelling process of buffer material. A wetting alternative based on short pipes led through the compart-ment plug was devised in 2009. The laboratory tests for studying erosion in this alternative have been completed.

One of the many questions to be resolved is rock spalling and its sig-nificance as a potential flow route at the ceiling of the deposition drift. Rock spalling is the result of stress-induced loads (bedrock stress), excavation work and thermal stresses caused by an in-crease in bedrock temperature. The analyses on the spalling of the Olkiluo-to bedrock will be updated during 2010 when the results of the POSE (Posiva Spalling Experiment) field test carried out in ONKALO (regarding spalling strength, etc.) are available. The backfill

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components used for backfill solutions near the plugs as well as in drift sections unsuitable for depositing supercontain-ers have also been designed during this project phase. The detailed design of the end plug for the deposition drift also takes place during this project phase.

The two other sub-projects of the horizontal disposal solution develop-ment project are entitled Tuotanto ja toiminta (Production and operation) and Demonstraatio ja täysimittakaa-vaisten testien suunnittelu (Demonstra-

tion and planning of full-scale tests). The objective of the first sub-project is the development of production lines, plants and system descriptions. The re-maining tests for the installation device are also included in this sub-project, as are the industrial safety and environ-mental issues related to the KBS-3H so-lution as well as the layout studies for the Forsmark and Olkiluoto repository facilities. The latter sub-project will be responsible for manufacturing compo-nents and production equipment and

their installation and testing in Äspö, as well as for the planning for the next project phase. Full-scale testing of the partitioning plug was carried out dur-ing 2009.

The work for specifying the Rock Suit-ability Criteria (RSC) for the horizontal disposal solution will begin in 2010. The KBS-3H layout will also be updated to correspond to the KBS-3V layout pro-duced in 2009.

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Olkiluoto monitoring programme

ONKALO, HZ20Aand B structures andthe GWMS pressuremonitoring network( the black disksrepresent plugs; thepressure monitoringsections are markedin blue ).

The long-term changes possibly caused by the construction of ONKALO are monitored using a special programme (OMO) established for the purpose (Posiva 2003-05). The scope of the programme includes rock-mechanical, hydrological and hydrochemical moni-toring and the monitoring of the envi-ronment and foreign substances. The results of monitoring studies are pub-lished separately for each field of re-search as part of the series of Posiva’s working reports.

Rock mechanics

In 2009, rock-mechanical monitoring continued as in previous years. Micro-seismic data was continuously analysed and monitored. The new metering sta-tion installed in ONKALO at the end of 2008 has operated without any prob-lems. Preparations were made in late 2009 for installing the next metering station in ONKALO. The purpose of the new metering positions is to devel-

op the metering station network and to further improve the accuracy of results.

GPS measurements in Olkiluoto and its surrounding areas were taken in the spring and autumn as in previous years. Precision levelling of the fixed points in the bedrock was also performed in the vicinity of ONKALO and the VLJ repository. The purpose of these meas-urements was the same as that of the microseismic measurements, i.e. to further reinforce the opinion regarding the stability of the Olkiluoto bedrock and to assess, among other things, the variations in the land uplift rate in Olkiluoto and its neighbouring areas. A development plan was drawn up for the GPS station network in 2009. Its purpose is to expand the area of ob-servations by a few new measurement points and to improve the accuracy of measurements by updating part of the stations for continuous measurement.

During 2009, convergence measure-ments were carried out in ONKALO at two levels (-180 m and -290 m) during

and after shaft raise boring. The pur-poses of these measurements include studying the deformations of bedrock caused by raise boring and further speci-fying the data on bedrock stability. The processing of convergence measure-ment data provided further information on the field of stress prevailing in the Olkiluoto area.

Hydrological features

Hydrological monitoring continued in 2009 mainly following the same pro-gramme as in 2008. The biggest change from previous years was in the change of focus from monitoring the flow conditions in boreholes to monitoring pressures.

Groundwater level observations were made in both shallow groundwa-ter tubes and boreholes and in deep open boreholes using manual methods once a month. The monitoring of pres-sure heads took place using the auto-matic pressure monitoring network of multiple-plugged boreholes (GWMS).

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The supply of GWMS data by e-mail and its online monitoring operated in 2009 as planned, and data processing and analysis was further developed.

By the end of 2009, a total of 27 deep boreholes had been fitted with multi-ple plugs and added to the monitoring network; one of these holes was fitted with multiple plugs during 2009. The need to increase the number of holes with plugs, expressed in R&D plan TKS-2006, was in the main satisfied during 2007 and 2008 when all deep bore-holes located near ONKALO and pen-etrating major water-conducting struc-tures were fitted with plugs. Increasing the number of plugged boreholes has significantly improved the accuracy of pressure monitoring and prevented the conveyance of pressures through open holes. Now geochemical observations also have indications of the positive ef-fects of plugging in the form of reduced mixing of waters from different water-conducting structures. Major water-conducting HZ20 structures were pen-etrated by the access tunnel of ONKA-LO in late 2008 as well as at the turn of 2008–2009, and the same structures were penetrated by shaft grouting holes during 2009. The impacts of structure penetration-related leaks on groundwa-ter pressure were monitored and ana-lysed during 2009.

A quarterly memorandum was compi-led during 2009 as planned, discussing the results of level and pressure head meas-urements and analysing the short-term impacts of other field events and ONKA-LO construction work on pressure heads.

In addition, the flow conditions in open holes ware monitored, together with groundwater salinity, runoff sur-face water volumes, seawater level and seepage waters in ONKALO. Transverse flow measurements were only made in campaigns while instrumentation de-velopment work continued. Of the pa-rameters included in the hydrological monitoring programme, the runoff sur-face water volumes, rainfall (including snow), thickness of ground frost and seepage are reported in the annual en-vironmental monitoring report.

The monitoring activities in ONKA-LO continued during 2009 with measu-

rements of total seepage water volumes taken approximately every two weeks. The measurements are taken, as far as possible, for the entire length of the tunnel and from measuring weirs, the total number of which at the end of 2009 was seven (at chainages 208, 580, 1255, 1970, 3003, 3125 and 3356). Structures HZ20A and B are located be-tween measuring weirs 3125 and 3356. The average total volume of seepage waters in ONKALO has increased from 2008 (20 litres/min in 2008, 33 litres/min in 2009). The main reasons for this are the penetration of HZ20 struc-tures and raise boring of three shafts to level -290 m. A visual inspection of seepage water volumes covering the entire length of the tunnel was carried out twice in 2009 in order to identify the location of leaking fractures and zones and to monitor any changes tak-ing place in them.

Hydrogeochemistry

The hydrogeochemical monitoring pro-gramme was, in the main, implemented in line with the sampling plans drawn up in 2008. However, slight changes were made to the original sampling plan in the autumn 2009 when indications of possible changes in salinity – for exam-ple, in research boreholes OL-KR1 and OL-KR7 – were received from SAMPO scanning. Local changes in salinity and impacts of the Korvensuo basin in the groundwater pipes and bedrock holes in its vicinity can be observed among the results of 2009 sampling. The monitor-ing results will be reported in the spring 2010, and the plan is to also analyse the reasons for changes in that connection. The changes in groundwater composi-tion may be caused by different sam-pling methods used at different times, the construction of ONKALO or other construction works in the area.

Groundwater samples have been taken in ONKALO according to the programme, primarily from groundwa-ter stations. Five groundwater stations were regularly monitored during the year. Studies of groundwater chemistry and microbiology have been conducted on the groundwater stations. The com-

position of groundwaters has remained the same in the areas near ONKALO.

The studies on the immediate im-pacts of ONKALO construction work continued with water sampling from fractures leaking water as well as from measuring weirs and waters pumped from ONKALO. The construction of ONKALO, in particular shotcreting, causes from time to time considera-bly high pH values (10–12) in waters pumped from ONKALO. However, it has been found that the pH of water pumped from ONKALO neutralizes reasonably quickly in the sedimentation pool and the drain ditch leaving it, and no harmful effects on the environment have been observed so far.

The environment

The work of monitoring the surface environment in Olkiluoto continued in 2009, primarily in line with the planned research programme. As in the previ-ous year, several campaign-style stud-ies were carried out in addition to reg-ular studies. In addition to the actual monitoring studies, other environmen-tal studies were also conducted, as in previous years, in order to describe the current state of the area.

The regular monitoring of the state of forests continued throughout the year on three intensive testing plots, including observations on the vegeta-tion, forest litter, root systems, micro-climate, wet deposition and grove wa-ter. The fourth intensive testing plot was established at the western end of the Olkiluoto island, and the intention is to have the entire study regime in op-eration there during 2010. Preparations are being made with the new intensive testing plot and five other testing plots for changes in land usage on the sur-vey area.

The seepage waters from the dump-ing site for rock material quarried from ONKALO were monitored on three oc-casions. Water samples were taken from the Korvensuo basin and from the Eurajoki river, as well as from the four ditches fitted with automatic measur-ing weirs in 2008. The water levels and water quality in three privately-owned

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drilled wells was also monitored. Sam-ples of animal plankton were taken at one observation location in the sea for the purpose of supplementing the moni- toring programme that TVO is obligated to operate.

A seasonal survey of game stock was conducted by interviewing local hunt-ers. The trapping campaign of 2008 for small mammals was repeated as part of the monitoring programme, albeit with a smaller number of traps. The popu-lations of ants, gastropods and earth-worm were surveyed in addition to the actual monitoring programme.

An extensive aerial photography campaign was carried out in late May, covering an area of over 200 km2 from the coast to the centre of Eurajoki. The

purpose of repeated aerial photography campaigns is to monitor any changes taking place in land use, and with it, also in the natural habitat.

The environmental surveys commis-sioned by TVO were also monitored in addition to the above environmental studies carried out by Posiva.

Foreign materials

The monitoring and control of foreign materials is part of Posiva’s monitoring programme. Foreign substances refer to all those materials and substances used for constructing ONKALO that are not part of the disposal system. Records were kept during 2009 of foreign ma-terials, and the materials manual was

updated with respect to the permitted and prohibited construction materials.

The impact of cement and its addi-tives as well as that of materials used for concealed drainage on microbial growth was also studied in 2009. The study on the impact of colloid silica, used as the grouting material for small fractures, on the migration of radionuclides in a pos-sible transient situation was also com-pleted during 2009.

By the end of 2009, a total of 521,000 kg of cement had been used for grouting and 2,416,000 kg for shot-creting. During the entire construction project so far, 836,000 kg of explosives and 12,500 temporary and final rein-forcement bolts have been used.

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The purpose of nuclear non-prolifer-ation control by Posiva is to ensure compliance with the relevant legislation and international treaties governing the matter during the construction phase of ONKALO.

Posiva has produced a nuclear non-proliferation control manual that de-scribes the nuclear non-proliferation control during the construction phase of ONKALO from 2012 until the planned construction licence application phase for the final repository. The nuclear non-proliferation control manual was up-dated in 2009. The manual defines the preliminary, actual and monitoring data concerning ONKALO that is reported quarterly to STUK. In addition, STUK carries out physical inspections, includ-ing the inspections of the ONKALO rock facilities and periodic inspections of the entire nuclear non-proliferation control system.

During 2009, STUK performed three periodic inspections of nuclear non-pro-liferation control measures in ONKALO, plus an inspection of the entire nuclear non-proliferation control system. Repre-sentatives from the IAEA and Euratom participated in the inspections as ob-servers. No cause for complaint con-cerning ONKALO nuclear non-prolif-eration control was raised in these in-spections.

The monitoring of the excavation of underground rock facilities is based on the requirement to demonstrate that ONKALO does not include any facili-ties which are not indicated in the de-sign data. Monitoring makes use of the microseismic station network built in Olkiluoto; the surveillance data of the network provides up-to-date informa-tion about blasting in Olkiluoto and in the nearby area. This system has proven to be a good and only method available

to date for monitoring the excavation operations from the outside. However, the microseismic monitoring system is only capable of detecting blasting, and it does not detect work performed using the so-called tunnel boring method, but filters it out as background noise. Posi-va has investigated the possibilities for making observations of the tunnel drill-ing method during the process of raise boring the shafts in 2007 and 2008. The results indicated that observation is technically possible but requires spe-cial equipment. The investigations will continue during the next raise boring operation in order to improve the cost effectiveness of monitoring through automation.

The reporting and monitoring op-erations are now well established and comply with the definitions of the nu-clear non-proliferation control manual.

Control of nuclear materials and nuclear non-proliferation control

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Operating waste management

The Olkiluoto repository for operating waste (VLJ reposi-tory) was commissioned in 1992. The repository consists of two rock silos, a hall connecting the two and auxiliary facilities constructed at a depth of 60–100 metres inside the bedrock in the Ulkopää cape of the Olkiluoto island. The facilities can be accessed both via the access tunnel and a shaft. Low-level waste is deposited in the rock silo in-side a concrete box, while a silo of steel-reinforced concrete has been constructed for intermediate-level waste in the other rock silo. The silo for low-level waste has a capacity of about 5,000 m3, while the capacity of the intermediate-level waste silo is about 3,500 m3. A preliminary design for the extension of the VLJ repository has been prepared in order to correspond to the increase in the operating life of OL1 and OL2 from the initial 40 years to the current 60 years, and in order to implement a disposal plan for op-erating and decommissioning waste from the OL3 plant unit under construction. The decision has also been made to take the needs of the possible fourth power plant unit

(OL4) into account in the future expansion plan for the repository facilities.Low-level and intermediate-level operating waste gener-ated at the Loviisa power plant is finally disposed of in fa-cilities built in the bedrock of the Hästholmen island. Con-struction work on the repository began in 1993, and its first phase was completed at the end of 1996. The repository was commissioned for disposal use in the summer 1999. The Loviisa repository consists of a 1 170-metre-long ac-cess tunnel, tunnel and hall facilities built at a depth of about 110 metres and of personnel and ventilation shafts. The facility was built in two stages. The first construction stage involved excavation all facilities and access routes. Two deposition tunnels were quarried for maintenance waste, and a repository hall was quarried for solidified waste. The second deposition tunnel and solidified waste hall were completed during the second stage that ended in 2007. The status of storage and disposal at the end of 2009 is shown in the table below.

The Olkiluoto power plant

OPERATING PRINCIPLEThe majority of operating waste is im-mediately packed for processing, stor-age and disposal. The intermediate-level ion exchange resins used for the purification of circulating water are so-lidified in bitumen, and the composi-tion is poured into steel drums. A part of the low-level waste (compressible miscellaneous maintenance waste) is

compacted in steel drums using a hy-draulic press, while another part (scrap metal and filter rods) is packed, without compaction, in steel and concrete cases and steel drums. The drums containing compressible waste are compressed so that the final height of the drum is approximately one-half of the original, with the diameter of the drum remain-ing unchanged. Scrap metal may also be processed before packing to reduce its volume. Scrap chopped up with a

metal chopper may be used to fill up any empty space in the concrete cases transported to the repository. This im-proves the packing efficiency of metal waste.

Miscellaneous liquid waste and slurry is solidified by mixing the waste with a binding agent in a drum that forms the packaging of the solidified product. If applicable, the volume of liquids and slurries is reduced through evaporation prior to solidification.

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Operating waste is temporarily stored in the storages and fuel pools of the power plant units, the low- and inter-mediate-level waste interim storage fa-cilities (the KAJ and MAJ storages) and, in small quantities, in the KPA storage at the Olkiluoto power plant site. Low and intermediate-level waste generated during the operation of the power plant is disposed of in the current waste silos of the repository for operating waste (the VLJ repository). Waste with very low activity concentration is exempted from control and taken to the landfill area located at the Olkiluoto power plant site or handed over to another party for recycling or other purposes.

CURRENT STATUS OF STORAGE AND DISPOSALThe status of storage and disposal at the end of 2009 is shown in the table on the next page. The waste is packed in bar-rels (200 litres in each, about 100 litres when compressed), to steel crates (1.3 or 1.4 m3 in each) and in concrete crates (5.2 m3 or 3.9 m3 net in each).

The barrels and crates are stored, when required, in storage facilities of plant units and the KAJ storage before

their final disposal in the VLJ repository. Before transferring them to the VLJ repository, the barrels and steel crates are placed in large and small concrete crates as follows: 16 barrels, or a com-bination of seven barrels and two steel crates, are placed in each large concrete crate and 12 barrels are placed in each small concrete crate. The number of bar-rels accommodated by the concrete box-es can be doubled by compressing them.

Dismantled waste from inside the reactor, such as core lattices and steam separators, is included in the waste packed in crates of 1.8 m3 for long-term storage in the fuel pools of plant units.

Large contaminated metal compo-nents are stored in the KAJ storage and in the MAJ storage extension. In addi-tion, unpacked operating waste such as used ventilation filters and resins without bitumen, are stored at the plant units, while waste oil is stored at the in-terim spent fuel storage (KPA storage). Part of the scrap metal is packed in the concrete crates used in the VLJ reposi-tory. Part of the unpacked waste is to be later released from control for recycling use or dumping on landfill sites. For example, waste oil of very low activity, of

which some 7.2 m3 had accumulated by the end of 2009, may later be released from control for recycling.

The waste buildings at the plant units can accommodate about 1,000 barrels each. Mostly only very low-level main-tenance bags and scrap to be released from control is kept at the MAJ storage. The KAJ storage can accommodate barrels, crates and large contaminated metal components corresponding to a total volume of some 6,000 barrels.

The capacity of the intermediate-level waste silo in the VLJ repository (expressed in 200 litre barrels) is 17,360 barrels while that of the low-level waste silo is 24,800 barrels. In other words, the total storage capacity of these two silos is about 8,400 m3 of operating waste packed in barrels. This corre-sponds to the quantity of waste gener-ated by two plant units during 40–60 years of operation. More repository facil-ities can be constructed in the bedrock of the area as required as an extension of the VLJ repository to accommodate the disposal needs of operating and de-commissioning waste.

The small waste items held by the Radiation and Nuclear Safety Authority

Reactorbuildings (m3) VLJ repository (m3) Other storages (m3)

TotalOL1 OL2 KAJ silo MAJ silo Others KAJ MAJ

Spentfuel

interim storage

LOW-LEVEL WASTE

Scrap 0,2 2400,1 0,2 2400,5

Unpacked scrap 18,0 1040,0 1058,0

Maintenance waste 10,0 13,2 928,6 3,2 955,0

Miscellaneous waste 0,8 2,4 3,2

Solidified liquids 4,0 0,2 92,2 96,4

Waste oil 7,2 7,2

INTERMEDIATE-LEVEL

Scrap 247,1 53 300,1

Resin powders 21,0 35,0 1262,0 1318,0

Resin granules 10,2 258,2 0,2 268,6

TOTAL 46 51 1767,3 3420,9 56,2 18,2 1040,2 7,2 6407,0

OPERATING WASTE GENERATED BY THE OLKILUOTO POWER PLANT

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The Olkiluoto VLJ repository in its extended state, seen from south-west. The two silos seen on the background belong to the part of the VLJ repository in use. The expansion plan has space reserved for the operating waste of two new plant units and decom-missioning waste of four plant units.

are stored, by separate agreement, in the Olkiluoto VLJ repository. These small waste items mainly consist of ra-dioactive substances used in hospitals, research institutes and industrial plants. So far, about 57 m3 of small waste items has been accumulated in the VLJ repository.

Expressed in terms of disposal vol-ume, the filters of OL1 and OL2 plant units have a total of 4,845 kg (computa-tional figure) of resin powders and gran-ules in bitumen. The waste containers in the waste buildings of the OL1 plant unit contain an additional 6,000 kg (computational figure) of resin pow-ders, while those in the OL2 plant unit have 1,800 kg (computational figure) of resin granules in bitumen.

RESEARCH RELATED TO OPERATING WASTEMicrobiological decay of low-level main-tenance waste is being studied in a large-scale test performed with testing equipment erected in the VLJ repository excavation tunnel. The study serves to further specify the amount of gas gen-erated from maintenance waste and to further knowledge of the whole decay process under conditions which are similar to those after the VLJ repository

has been sealed off. In addition, the release of activity from the waste barrels to surrounding water is also monitored.

The most important parameter achieved in this test is the rate of gas generation in maintenance waste; this parameter is needed for the VLJ reposi-tory safety analysis. In the long-term, the rate of gas generation has been of the order of 60–90 dm3/month which is one order of magnitude lower than what was estimated in the original safety analysis. The pH of the test tank clearly decreased during the gas generation test. At the beginning of the test in 1999–2002, the pH was 10–11 while it has been 8–9 during 2003–2009.

IN-SERVICE STUDIES REGARDING THE VLJ REPOSITORYIn-service monitoring of the VLJ re-pository rock facilities continued dur-ing the year being reported in compli-ance with the research and monitor-ing programme produced earlier. The results of hydrological monitoring of the VLJ repository during 2008 were reported in mid-2009. Extensive moni-toring samples were last collected from the groundwater stations in the spring 2008. The most significant changes in groundwater quality were a decrease in

sodium and chloride concentration and the halving of potassium concentration in two years. The next extensive sampling campaign is scheduled for 2011 in the VLJ repository bedrock research and monitoring programme.

In the spring 1993, ten test bolts were installed in the research tunnel of the Olkiluoto VLJ repository for the purpose of determining the rate of corrosion in rock bolts. The purpose of the study is to produce information of the corrosion resistance of zinc-plated rock reinforce-ment bolts in the conditions prevailing at the Olkiluoto VLJ repository assum-ing that the cement plaster protecting the bolts has totally lost its protective properties. The first test bolt was drilled out in 1996 and the next in 2004. The results for the latter bolt were reported in 2006. The next bolt is scheduled to be drilled out in 2010 provided that the conditions in the bedrock are found to be sufficiently representative for reliable results.

The Loviisa power plant

Low-level and intermediate-level reac-tor waste generated at the Loviisa NPP is processed and stored at the plant. Used ion exchange resins and evaporator

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  Total amount of waste Activity

 

At the plant/in storage buildings

At therepository

  (m3) (m3) (GBq)

Used ion exchange resins 514 15700

Evaporation residues 637 1200

Solidified  evaporation  residues and ion exchange resins

17 < 1

Solvents solidifiedby absorption

24 < 1

Maintenance waste 358 1586 655

OPERATING WASTE GENERATED BY THE LOVIISA POWER PLANT

bottoms are stored in tanks in the liq-uid waste storage. Trial runs of the liq-uid waste solidification plant based on cementation took place in 2008–2009, and the plant will be commissioned in 2010.

In the early 1990s, a method was in-troduced in Loviisa for separating radio-active cesium from evaporation residue into a very small waste volume. The re-moval of cesium reduces the activity of the evaporation residue to such a low level that it can be discarded using nor-mal drainage procedures. By the end of 2009, a total of more than 1,300 m3 of evaporation residue had been purified at the cesium separation plant using 29 ion exchange columns, each with a vol-ume of eight litres. The next cesium ex-traction campaign will take place in 2010.

Dry maintenance waste generated in power plant maintenance and re-pair work is packed into 200-litre steel drums. Compressible waste is pressed into the drums using a baling press; in this way, one drum may be made to hold three to four times more waste than without compression.

In 2009, 3 m3 of hazardous waste released from control and 1,080 fluo-rescent tubes were sent to Ekokem Oy. Metal waste generated in the controlled area is exempted from control in cam-paigns, as the situation requires, and collected into suitable waste batches. Before official exemption from control, metal waste found uncontaminated in

radiation monitoring is kept in interim storage in a storage hall located in the yard area. In 2009, a total of 48,520 kg of metal waste was released from con-trol and sent to Kuusakoski Oy.

Interim storage of radioactive metal waste takes place in the storage facili-ties of the controlled area. The storage hall for maintenance waste barrels to be released from control also holds one ocean-freight container full of contami-nated metal waste. This metal waste will eventually be disposed of in the VLJ repository.

A project concerning the renovation of the low-level maintenance waste treatment and storage facilities is un-derway. In the autumn 2007, the con-struction of a conventional storage and repair shop building, exempt from con-trol, started. The electrical and machine repair shops have already moved to the new building. After the completion of the new building and removal of func-tions, the controlled area will be extend-ed to the facilities, which then become vacant. In the controlled area extension at LO1, facilities for maintenance waste treatment, a decontamination facility and a repair shop facility will be imple-mented. For LO2, facilities for metal waste and recyclable metal handling will be implemented. The new facilities in the controlled area are due to be fully commissioned in 2010. Gammaspectro-scopic measuring equipment for drum waste (determination of gamma activ-

ity, automatic drum conveyor, weighing rotator, etc.) was ordered in 2008 and will be installed in 2010.

The finishing work of the solidifica-tion plant (cementing plant) for liquid/wet active operating waste was com-pleted in 2008, and trial operation us-ing evaporation residue took place. Trial operation on used ion exchange resins took place in 2009, and the process of obtaining an operating licence for pro-duction use was postponed to 2010.

In 2009, low-level solvent waste was solidified by absorption in 200-litre bar-rels so that a total volume of 7 m3 of barrels was accumulated.

The status of storage and disposal at the end of 2009 is shown in the table below. Used ion exchange resins and evaporation residues are stored in the liquid waste storage. 1.7 m3 of this is kept in solidified form in barrel-shaped waste containers. The solvent waste so-lidified by absorption and maintenance waste are kept in 200-litre barrels.

REPOSITORYLow-level and intermediate-level waste generated in the operation of the Lovi-isa power plant is finally disposed of in facilities built in the power plant area bedrock. The repository received its operating licence in 1998 and was com-missioned as a maintenance waste re-pository in 1999.

The repository consists of a 1,170 metre long access tunnel, tunnel and hall facilities built at a depth of about 110 metres, and of personnel and ven-tilation shafts. The facility was built in two stages. The first construction stage involved excavation all facilities and ac-cess routes. Two deposition tunnels were quarried for maintenance waste, and a repository hall was quarried for solidified waste. At this stage, only one maintenance waste tunnel was com-pletely built as well as the systems serving the whole disposal plant. The construction and installation work of the second stage of the repository was performed in 2004–2006. The finishing work of the earlier constructed mainte-nance waste repository facility 2 (HJT2) began in November 2004, and this fa-cility was commissioned for disposal

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Maintenance waste repository at the Loviisa power plant.

use in May 2005. The construction and installation work of the earlier quarried solidified waste repository (KJT) started in the spring 2005, and they were com-pleted at the same time as the seepage water pool built in the repository facili-ties. Finishing operations were carried out in 2008. The solidified waste re-pository will be needed for the disposal of waste packages to be brought from the solidification plant starting in 2011.

Separate research programmes have been compiled for in-service research concerning the access tunnel and hall facilities.

STUDIES ON SOLIDIFICATION METHODSStorage testing of radioactive ion ex-change resin solidified in half-scale disposal containers in 1987 continued. The waste packages have been stored in groundwater at the Loviisa power plant for 21 years and, as expected, they

are still in good condition. No struc-tural damage has been detected in the concrete surface of the containers, and the composition of the storage water has been relatively stable. Radioactiv-ity monitoring of the storage water has not revealed any signs of nuclide release from the solidified product contained in the concrete containers. The latest report on test results was drawn up in 2004, and the next report is due in 2010.

In 1980, old inactive ion exchange resin from the Loviisa power plant was solidified in a full-scale disposal con-tainer. The disposal container was kept in storage until mid-1983, and it has since then been kept in slowly flow-ing fresh water at the Pyhäkoski power plant. The condition of the disposal con-tainer has been monitored after 1, 3, 5, 9, 13, 15 and 21 years of storage. Rusting can be clearly seen on the steel lifting lugs and fastenings but no structural damage has been detected on the con-

tainer’s concrete surface, and no corro-sion has been detected in the concrete reinforcements of the container. The test results were last reported in 2004 together with the results of the half-scale container test, and this procedure is to be repeated in 2010.

IN-SERVICE STUDIES REGARDING THE REPOSITORY The in-service studies on the reposi-tory continued in 2009 in line with the monitoring programme. The aim of the programme is to investigate and moni-tor the characteristics and behaviour of groundwater and the bedrock in the im-mediate surroundings of the disposal facilities as well as long-term changes in their behaviour.

The monitoring programme has included the monthly monitoring of groundwater levels in ground-level re-search holes. The position of fresh and so-called saline groundwater in the holes was measured on four occasions during the year. The electrical conduc-tivity and pressure of groundwater as well as the seepage water volumes have been measured at the repository facilities once a month. Some pressure and seepage water measurements have also run continuously. The measure-ments concentrated on the seepage water pools and on the five purpose-built groundwater stations. The research programme on groundwater chemistry included sampling and analysis of sam-ples from groundwater stations LPVA3 and LPVA5. In addition, the results of samples taken in the previous year from station LPVA2 were reported. Bedrock monitoring has been performed main-ly using an automated rock-mechanical measuring system. Visual inspections of the facilities also continued in 2009.

The groundwater in the island of Hästholmen is characterized by the fact that its level clearly depends on the sea-water level. This is most evident in deep boreholes where the groundwater level is close to the seawater level. In shallow holes, the level is a few metres higher, depending on the topography. During the time the repository facilities were be-ing constructed, the groundwater level sank locally by a few metres in the areas

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Maintenance waste repository at the Loviisa power plant.

surrounding the facilities, but the slow rising of the levels has been observed since the facilities were completed. As a whole, no significant changes have taken place in water levels that seem to have stabilised roughly at the 1996 level. The borderline between fresh and saline groundwater has remained between lev-els -30 m and -80 m as in previous years, i.e. clearly above the repository facilities that are located roughly at level -110 m.

The electrical conductivity meas-ured in conjunction with seepage water measurements varies from one part of the facilities to another, as in previous years, in the range 500–1,600 mS/m. These values represent both the inter-mediate zone and the saline zone. The electrical conductivity increases with in-creasing depth (and salinity) and reach-es its maximum value at station LPVA5 (level -110 m). The conductivity of seep-age water pumped into the sea (a mix-ture of all seepage waters) has been about 1,200 mS/m on average.

The analysis results of samples tak-en from groundwater stations have not significantly changed from previ-ous years. The pH value at station LP-VA2 (7.4) has slightly increased (pre-vious value 7.2 ± 0.1), while the pH at

LPVA3 has remained constant (7.7 ± 0.1) since 1999, as has the pH at LP-VA5 (7.6 ± 0.1), which has been the same since 1996. The electrical con-ductivity and TDS values of ground-water were at LPVA2 1,340 mS/m and 7,600 mg/l, at LPVA3 1,100 mS/m and 5,800 mg/l, and at LPVA5 1,550 mS/m and 8,880 mg/l, respectively. The groundwater is of the Na-Ca-Cl type, and its TDS classification is that of brackish water.

The effects of seawater level varia-tions and location are clearly evident in the groundwater pressure values. The pressure increases with increas-ing depth and reaches its maximum value bar at station LPVA5 located at the lowest point (at an approximate level of -110 m) where it is about 10.3 bar, slightly lower that the theoretical value of 11 bar.

The amount of seepage water was measured, as usual, at seven different points around the disposal facilities. After excavation work was completed in 1996, total seepage was about 300 l/min at its highest, from which it has fairly constantly fallen to about 80 l/min by the end of 2009. About half of the seepage water amount comes from the

access tunnel and the other half from other facilities. Measurement results indicate that the maintenance waste facilities are practically dry.

The results of rock-mechanical measurements show that the stability of the facilities has remained good and, for example, that the construction of the repository for solidified waste has not diminished the stability of rock in the immediate surroundings either. During the construction work in 2005–2006, more variations were observed in bed-rock movements, mainly as a result of the higher temperature in the hall, but now the movements have returned to their pre-construction level. Extenso-meter measurements indicate that the dislocations taking place at the ceilings and walls of rock facilities have been of the same order as in previous years, be-low 0.1 mm. Bedrock movements in the vehicle access and connecting tunnel are monitored by convergence measure-ments that have a resolution of 0.5 mm. The results indicate that the movement has been smaller than 1 mm. The bed-rock temperature near the facilities at a depth of -110 m is about 8–12 degrees.

Visual inspection of the facilities indicates that their overall stability is

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good. The concealed drains operate as planned, albeit the precipitation of iron contained in the groundwater requires that they are periodically cleaned in the access tunnel. Saline seepage wa-ter causes localized corrosion of metal structures and also gives rise to occa-sional maintenance and repairs.

SAFETY REPORTS REGARD-ING DISPOSAL OF OPERATING WASTE

The construction and installation work of the solidified waste repository (KJT) of the Loviisa power plant started in

2005, and they were completed in 2007 at the same time as the seepage water pool built in the repository facilities. The work of updating the safety case for the repository began in the spring 2004 and was completed in the spring 2006. The safety case deals with phenomena, events and processes which affect long-term safety, such as groundwater flows, the release of radionuclides from waste, their migration in the bedrock and bio-sphere, and many other specific issues. According to the safety analysis, the ra-diation doses emanating from dispos-al are below dose limits, and the doses coming via waterways (lake, sea) are

only a fraction of natural background radiation doses. Similarly, the deposited waste causes only a limited increase in total activity concentrations of radioac-tive substances in the environment. Ac-cording to the safety case, it is not even possible to identify any fairly probable chains of events which could deterio-rate the long-term safety of disposal to an inadequate level.

During the year being reported, in-ternational developments in operating waste disposal were monitored through one conference visit and trade publica-tions.

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Decommissioning reports

According to the Nuclear Energy Act, the NPP licence holder is also respon-sible for decommissioning the plant. In order to fulfil this obligation, the party responsible for waste management must produce a report on the decommissioning methods and schedule as well as on the storage and final disposal of decommissioning waste. The power companies have presented their updated decommissioning plans at five-year intervals until 2008 when the frequency for submitting updated decommissioning plans was changed to every six years. The latest updated plan was completed late in 2008 for both the Loviisa and Olkiluoto nuclear facilities.

The Olkiluoto power plant

The decommissioning studies are aimed at the technical and economical development of the decommissioning plan and at specifying the initial data for the safety analysis. The long-term safety analysis of the disposal of decommis-sioning waste from the Olkiluoto nu-clear power plant was updated during 2008 The safety analysis takes into ac-count the decommissioning waste from four plant units (OL1, OL2, OL3 and one plant to be constructed later). Further-more, in 2008 a principal plan was com-pleted for an extension to the disposal facilities for operating and decommis-sioning waste. The plan also took into account the waste from the OL3 plant unit and the potential fourth plant unit.

A report was produced during 2009 regarding the decommissioning costs of the OL3 plant unit. The results will be presented in the preliminary decom-missioning plan for the OL3 plant unit scheduled for production during 2010. A report was produced for the purpose of further specifying the decommissioning costs of the Olkiluoto NPP. It analysed the decommissioning costs in a case where the plants are decommissioned before the service life of 60 years fore-seen for the OL1 and OL2 plant units had expired.

Used internal parts of reactors, clas-sified as intermediate-level waste, are

mainly only disposed of in conjunction with decommissioning. The parts will be stored in plant unit water pools and a separate inventory for them will be kept. Intermediate-level and low-level waste generated in decommissioning and the used reactor internals accumulated dur-ing the operation of the power plant will be disposed of in the planned extension part of the VLJ repository.

A database application is available for planning the decommissioning of the contaminated part of the power plant. The database helps to calculate the amounts of material, the amounts of radioactive isotopes, working time nec-essary for dismantling, workers’ dose rates, accumulative doses, and costs. An update of the database was com-pleted in the spring 2008.

Long-term corrosion tests of carbon steel in the VLJ repository excavation tunnel and laboratory tests in concrete water and bedrock groundwater envi-ronments started in late 1998. The tests are performed in conjunction with re-search into concrete so that some car-bon steel pieces are placed in the same drilling hole (VLJ-KR21) with concrete test pieces and some are placed in their own hole (VLJ-KR19). Water chemistry in the drilling holes was monitored with regular pH, oxygen, redox potential and conductivity measurements, in addition to which water samples for chemical analyses are taken annually.

The reported year 2009 was one dur-ing which no sampling for the solubil-ity tests of metallic decommissioning waste took place. The numbers of sam-ples collected from the boreholes in the VLJ research tunnel of Olkiluoto by the end of 2009 were as follows:– KR9: 12 zinc plate samples and 11 samples of thin zinc-coated steel plates– KR19: 36 samples of steel plates, installed in 2007– KR21: 36 samples of steel plates, installed in 1998

No samples were taken in 2009 of concrete or metallic decommission-ing waste.

The Loviisa power plant

During the operation of the Loviisa power plant, low-level and intermediate-level nuclear waste is generated which will only be deposited in connection with decommissioning. This waste includes, for example, used protective elements, absorbers, neutron flux de-tectors, connector rods of control rods and fission chambers.

At the and of 2009, there were 218 used protective elements, 220 ab-sorbers, 253 neutron flux detectors, 135 connector rods and 27 fission cham-bers at the Loviisa power plant. Of these, the protective elements were kept in the spent fuel storage pools of the plant and absorbers and fission cham-bers were kept in purpose-built chan-nels at spent fuel storage 1. The neu-tron flux sensors and connector rods were stored in similar channels in the reactor hall.

At the end of 2008, the latest update for the decommissioning plan for the Loviisa power plant was completed on the basis of a 50-year operating life. The plan includes, among other things, an activity inventory, dismantling actions,

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radiation dose estimates, the amounts of components and packages for dis-posal, a safety case for the disposal of waste and estimates of work and costs. The waste and cost estimates rose clearly from the previous 2003 decom-missioning plan, mainly due to revised regulatory requirements (YVL 8.2). The decommissioning plan is based on the idea of dismantling immediately after the operation is finished with those ra-

dioactive parts which are not necessary for continuing the nuclear functions remaining at Hästholmen (spent fuel storing, wet waste solidification and disposal of low-level and intermediate-level waste).

A decision on decommissioning or continuing operation will only be made towards the end of the planned op-erating life. Similarly, the decision on whether the plant will be dismantled

immediately or in a delayed schedule will be made towards the end of opera-tion before starting decommissioning.

The studies carried out in 2009 in-cluded one on the licensing process for decommissioning and the project of separating storage pool no. 2 for spent fuel as an independent unit in contrast with the dry storage of spent fuel in con-tainers at the Loviisa power plant.

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Other activities

Management of quality and the environment

The preliminary assessment of Posiva’s environmental management system for the purpose of its certification was per-formed in 2009 by an external auditor. Internal audits and external audits of Posiva’s suppliers were carried out as part of Posiva’s operations manage-ment system, in compliance with the audit plan.

STUK controlled the construction of ONKALO in keeping with the agreed procedures. STUK carried out its inspec-tion plan RTO2009 regarding the con-struction of ONKALO as planned. Regu-lar STUK follow-up meetings were held between STUK and Posiva, and separate site inspections were performed. The STUK-approved schedule for submit-ting ONKALO design documents and the plan for giving information on con-struction details were observed in the ONKALO construction project.

The progress of site surveys and the disposal system development work were monitored as before in follow-up meet-ings between STUK and Posiva at rough-ly six-month intervals. The main issue discussed in 2009 was the setting of priorities for research and development activities in the coming years, and the objective was to specify the areas where the plans or level of information should be clearly improved from the current sta-tus by the time the construction licence application is submitted. At the same time, the discussions provided a basis for producing the TKS-2009 programme.

The EIA procedure regarding the ex-pansion of the repository, started in 2008, was completed when TEM (the Ministry of Employment and the Econo-my) issued its statement in March 2009 regarding the EIA Report. Immediately after that, Posiva submitted its decision-in-principle application for depositing spent nuclear fuel from Loviisa 3.

Licences and permits

Pursuant to KTM Decision 9/815/2003 dated 23 October 2003, TVO and For-tum submitted on 29 September 2009 a status report on the state of preparation of the documents referred to in Section 32 of the Nuclear Energy Decree, i.e. the documents to be attached to the con-struction licence application of the en-capsulation plant and the repository. At the same time, Posiva submitted draft versions of the documents to be attached to the construction licence ap-plication, as referred to in Section 32 of the Nuclear Energy Decree, to the Min-istry of Employment and the Economy. The ministry has circulated the above documents for comments, which are to be made by 30 June 2010. At the end of 2009, Posiva submitted to STUK (the Radiation and Nuclear Safety Authority) preliminary drafts of the licensing doc-uments referred to in Section 35 of the Nuclear Energy Decree.

Management of research data

RESEARCH DATA SYSTEMPosiva has plenty of research data, col-lected over a few decades in Olkiluoto and other localities where Posiva has earlier conducted studies and surveys. This extensive collection includes research data on the area’s bedrock, water areas in the surrounding environment, animal population and weather conditions.

As the studies have become more specific, the need to be able to access data quickly has become more impor-tant. At the same time, the number of people using the data has increased. In order to ensure that all users can quickly access the same verified and accepted data, it was deemed necessary to create a single centralised system, the POTTI research data system, which will store all research data produced and make it available to all authorised users.

The work on specifying the POTTI system began in 2004 with the speci-fication of data to be stored, intended uses of the database, the operating en-vironment and the extent of database usage. The production use of the POT-TI system began in March 2007, and different areas of research (hydrogeo-chemistry, hydrology, environmental monitoring, geology, geophysics, exca-vation documentation, rock mechanics) have gradually increased its use dur-ing 2007–2009. Among others things, the POTTI system has interfaces with the automatic groundwater measuring system in ONKALO, the HYPERDATA borehole data system and the Surpac bedrock modelling system. The work for developing the system and storing research data will continue further during 2010 –2012.

PROCESSING OLKILUOTO BOREHOLE DATAPosiva’s HYPERDATA system is intend-ed for viewing and visualising Olkiluoto borehole data stored in the POTTI sys-tem. The images of drill core box con-tents from Olkiluoto boreholes (OL-KR1–OL-KR53) and video images of borehole walls were processed and stored in the POTTI system during 2008–2009. In addition, ONKALO borehole data was similarly stored.

PROCESSING ONKALO EXCAVATION DATAThe construction of ONKALO began in June 2004. The excavation operations carried out so far were divided into four tunnel contracts (TU1–TU4), the last of which, TU4, started in August 2008. At the beginning of TU4, the decision was made to establish in the POTTI data-base a separate project entitled LOHI for planning data and as built-data re-lated to rock excavation operations. The project involved creating functional data saving procedures and storing the mass

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of data accumulated. In this project, which ended in August 2008, the ex-cavation data specified for contracts TU1–TU3 of the ONKALO project were processed and stored in the POTTI re-search data system. The LOHI-2 project was established in October 2009 for processing the corresponding data of the TU4 contract.

REQUIREMENTS MANAGEMENTThe VAHA requirements management project was established in 2006 for the purpose of planning and implement-ing a systematic procedure for managing the requirements concerning the dis-posal project. When implementing the project, Posiva’s earlier projects related to requirements management (in partic-ular management of the requirements concerning the ONKALO project) were taken into account, as was the experi-

ence accumulated elsewhere, in parti-cular at SKB.

The goal of the project has been to create a data system for collecting all requirements concerning disposal and their grounds, details of solutions for meeting the requirements, as well as information on the linkages between different requirements.

In addition, the system to be imple-mented will allow quick viewing of com-patibility between individual specifica-tions and different requirements, sys-tematic analysis and documentation of the impacts of changes in requirements, as well as requirements management as part of the normal work of the line organisation.

The classification of existing require-ments and the production of corre-sponding contents will take place in separate teams, consisting of members

of the line organisation, that are related to the different subsystems of disposal operations (canister, buffer, backfill, clo-sure, technical facilities, technical sys-tems and transportation) with experts in the respective requirements participat-ing in the work. The teams provide the VAHA project with requirements data in line with the classification and struc-ture defined by the project. The work for checking and approving the require-ments has began at Posiva in line with the defined process description, using external experts as required.

The first version of the requirements database for disposal operations was in-troduced in the autumn 2007, the con-tents have been revised during 2008–2009, and this work will continue in 2010–2012.

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Provisions for the cost of nuclear waste management

The funds required for nuclear waste management are collected in the gov-ernmental nuclear waste management fund. The target for accumulating funds is determined on the basis of the total liabilities of nuclear waste management, confirmed separately each year. The to-tal liabilities of nuclear waste manage- ment include the future costs of all oper-

ations required for managing the quan-tity of nuclear waste accumulated by the end of the respective year.

TVO’s funding target for nuclear waste management in 2009 was EUR 1,001.2 million, while that of Fortum was EUR 766.9 million.

The Ministry of Employment and the Economy confirmed EUR 1,160.7 mil-

lion as TVO’s total liabilities for nuclear waste management at the end of 2009, and EUR 1,069.8 million as its funding target for 2010. For Fortum, the Min-istry of Employment and the Economy confirmed EUR 913.0 million as total liabilities for nuclear waste manage-ment, and EUR 829.7 million as its fund-ing target for 2010.

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POSIVA 2009-01 Olkiluoto Site Description 2008 Posiva Oy ISBN 978-951-652-169-8 POSIVA 2009-02 Olkiluoto Biosphere Description 2009 Reija Haapanen, Haapanen Forest Consulting Lasse Aro, Finnish Forest Research Institute, Parkano Research Unit Jani Helin, Posiva Oy Thomas Hjerpe, Saanio & Riekkola Oy Ari T. K. Ikonen, Posiva Oy Teija Kirkkala, Pyhäjärvi Institute Sari Koivunen, Lounais-Suomen vesi- ja ympäristötutkimus Oy Anne-Maj Lahdenperä, Pöyry Environment Oy Liisa Puhakka, Haapanen Forest Consulting Marketta Rinne, Agrifood Research Finland Tapio Salo, Agrifood Research Finland ISBN 978-951-652-170-4

POSIVA 2009-03 Manufacture of Disposal Canisters Leena Nolvi, Posiva Oy ISBN 978-951-652-171-1

List of reports

Posiva Oy, Olkiluoto, FI-27160 EurajokiTel +358 2 837 231, Fax +358 2 8372 3809

www.posiva.fi