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P i i a Juho la

June 2008

Work ing Repor t 2008 -26

Results of Monitoringat Olkiluoto in 2007

Foreign Materials

P i ia Juho la

Pos iva Oy

Work ing Report 2008 -26

Results of Monitoringat Olkiluoto in 2007

Foreign Materials

Working Reports contain information on work in progress

or pending completion.

June 2008

Base maps: ©National Land Survey, permission 41/MYY/08

Results of Monitoring at Olkiluoto in 2007, Foreign materials ABSTRACT This report focuses on foreign materials introduced to ONKALO. These foreign materi-als are not part of the multi-barrier system or the natural environment. All the allowed materials introduced to ONKALO are included in the material handbook. All materials used in ONKALO 2007 are listed in this report. During 2007 the ONKALO access tun-nel was excavated from chainage 1683 to chainage 2576 and the total excavated volume was 45425 m3. This report also summaries the total amounts of foreign materials used in ONKALO since 2004. All waters used during the excavation of ONKALO are pumped up to the surface into a sedimentation pool. In 2007 water samples were taken from sedimentation pool and from the outlet ditch. The chemistry of these waters can tell us how the use of foreign materials has affected to the baseline groundwater chemistry. Keywords: foreign materials, disposal of spent fuel, monitoring, Olkiluoto, ONKALO

ONKALOn monitorointiraportti 2007: Vieraat aineet TIIVISTELMÄ Tässä raportissa käsitellään ONKALOon vuoden 2007 aikana vietyjä materiaaleja. Vie-raat materiaalit eivät kuulu moniesteperiaatteeseen eivätkä kallioperään. Kaikki ON-KALOon sallitut materiaalit on listattu materiaalikäsikirjassa. Tässä raportissa on esitet-ty kaikki vuoden 2007 aikana käytetyt materiaalit. Vuoden 2007 aikana ONKALOn ajotunneli eteni paalulta 1683 paalulle 2576 louhitun kalliotilavuuden ollessa 45425 m3. Tässä raportissa esitetään myös kaikki rakentamisen aikana käytetyt vieraat materiaali-määrät rakentamisen alusta vuodesta 2004 lähtien. Kaikki ONKALOn rakentamisen aikana käytetty vesi pumpataan maanpinnalle sedi-mentaatio altaaseen. Vuonna 2007 vesinäytteitä otettiin sedimentaatioaltaasta ja pur-kuojasta. Näiden vesien kemian muutokset ennakoivat vieraiden materiaalien vaikutuk-sia perustilan vesikemiaan. Avainsanat: Vieraat materiaalit, käytetyn ydinpolttoaineen loppusijoitus, monitorointi, Olkiluoto, ONKALO

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TABLE OF CONTENTS ABSTRACT TIIVISTELMÄ 1 INTRODUCTION ....................................................................................................... 2 2 FOREIGN MATERIALS AND MATERIAL HANDBOOK ............................................. 4

2.1 Foreign materials ................................................................................................ 4 2.2 Material handbook............................................................................................... 4 2.3 Allowed foreign materials .................................................................................... 5 2.4 Forbidden foreign materials ................................................................................. 7 2.5 Quality control ..................................................................................................... 8

3 MATERIALS AND AMOUNTS USED IN ONKALO .................................................... 9

3.1 Safety level A ...................................................................................................... 9 3.1.1 Cement, concrete and additives ................................................................... 9 3.1.2 Organic compounds ................................................................................... 11 3.1.3 Nitrogen compounds .................................................................................. 11 3.1.4 Other inorganic compounds ....................................................................... 12

3.2 Safety level B .................................................................................................... 12 3.2.1 Metals ........................................................................................................ 12 3.2.2 Other materials ........................................................................................... 13

4 MONITORING OF ONKALO CONSTRUCTION ...................................................... 14

4.1 ONKALO process waters .................................................................................. 14 4.2 Sedimentation pool and outlet ditch .................................................................. 15

5 DISCUSSION .......................................................................................................... 22 REFERENCES ........................................................................................................... 23 APPENDIX 1……… ....... ……………………………………………………………………..25APPENDIX 2…… ...... ………………………………………………………………………..27

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1 INTRODUCTION

In July 2004 Posiva began to construct an underground rock characterization facility called ONKALO, which is planned to reach the repository level –420 m by the end of year 2009. The construction of ONKALO and subsequently the construction of the re-pository, will affect the surrounding rock mass and the groundwater flow system as well as the environment. In December 2003 a programme for monitoring at Olkiluoto during construction and operation of ONKALO was presented (Posiva 2003). A summary of the observations and measurements is reported annually for each discipline. Foreign materials is one part of the monitoring system, others are rock mechanics, hydrogeol-ogy, hydrogeochemistry and environment. The aim of this report is to give an overview of the progress of monitoring the foreign materials. This report presents the monitoring of foreign materials introduced into ONKALO since the start of construction in June 2004. Juhola 2005, Vuorio 2006 and Juhola 2007 presented the earlier results and progress of the foreign materials monitor-ing. The current foreign materials monitoring schedule is presented in Table 1. Table 1. The monitoring schedule of foreign materials during 2004-2012.

2004 2005 2006 2007 2008 2009 2010 2011 2012 Use of Foreign materials

amounts Sedimentation pool

EC and pH -monitoring Groundwater samplings

Outlet ditch EC and pH -monitoring Groundwater samplings

Leaking structures and frac-tures

Groundwater samplings

Continuous (on line) Continuous (weekly) Continuous (monthly) Measuring campaigns

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The underground parts of ONKALO consist of a system of exploratory tunnels accessed via a tunnel and three shafts: an exhaust air shaft, a personnel shaft and an inlet air shaft. It has been assumed that in the future ONKALO will be part of the spent nuclear fuel repository (Saanio et al. 2006). At the end of 2007 ONKALO's access tunnel was situ-ated at chainage 2576. Each tunnel chainage is one metre long. In 2007 the mined tun-nel volume was 45425 m3. The total mined volume of ONKALO tunnel was 122248 m3. In 2007 a personnel shaft was rising bored, first from level - 80 m to level -11 m and furthermore from level -180 m to level - 80 m. Also an exhaust air shaft was bored from level -180 to level -90. These shafts volumes are not including in this report. The inlet air shaft will be bored later.

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2 FOREIGN MATERIALS AND MATERIAL HANDBOOK

2.1 Foreign materials

Foreign materials referred also as engineering or stray materials, are those that are nei-ther part of the engineered barrier system (e.g. bentonite, copper canister) nor of the natural environment (rock material or groundwater). Some of the introduced foreign materials will be removed in different cleaning processes before backfilling, but some will necessarily remain in the future repository (Hjerpe 2003). The amounts of foreign materials have been estimated in Hjerpe (2003). These estima-tions have been updated by Hagros (2007). The updated estimations are based on the new repository layout produced in 2006 and consider the latest plans for grouting and rock support. Also amounts of foreign materials used until September 2006 have been taken into account. The most significant updates are the amounts of materials used in grouting, shotcreting and in support bolts. Foreign materials remaining in ONKALO mostly consist of the cement used for grout-ing and for shotcreting to stabilise the ceilings and the walls of the excavation (Vieno et al 2003). The estimated amount of grouting and shotcrete cement introduced in ONKALO is about 2900 tons (Hagros 2007). Approximately 20-25 % of pre-grouting materials are estimated to be removed during the excavation process. In this report the total amounts are reported, because the estimation of the removed amounts is difficult. According to present knowledge it is possible to remove shotcrete before backfilling. Another potentially harmful group of foreign materials consists of hydrocarbons, urine and nitrogen compounds from explosive residues and organic materials. The majority of the organic materials are estimated to originate from the ventilation air, other major sources of organic materials that will remain in ONKALO include cement additives, superplasticisers. Superplasticiser are used to improve the workability of shotcrete and grouting cement (Posiva 2003). Disadvantages of use of foreign materials are discusses in Vuorio 2006 and in Juhola 2005. As all the materials are not measurable, the amounts of these are based on estimations. These materials include rubber from tyres, exhaust fumes from diesel engines, hydraulic and lubricants oils, urine and other human waste. These amounts are not estimated here but are available in Hagros 2007.

2.2 Material handbook

The material handbook is a list of materials allowed in ONKALO. It includes separate instructions for all materials, material safety data sheets (MSDS) and other relevant in-formation. These materials have been divided into two safety levels: Safety level A (the highest safety level) includes materials, which could have impact on long-term safety. Materials in safety class B have no detrimental influence on long-term safety according to present knowledge. Safety level A includes cementitious materials and additives, organic compounds, inorganic nitrogen compounds and other inorganic compounds. Safety level B includes metals and other materials.

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Material handbook is saved electronically in Posiva’s Kronodoc-system and is so avail-able when needed. Every worker in ONKALO is obliged to check that the material needed is included in the material handbook and in the list of allowed materials. The instructions for introduction a new material are found in the material handbook. A new material can be approved for use in ONKALO if it is not harmful for long-term safety and it has to be suitable to ONKALO conditions. Its functionality must have been tested. For material in safety level A the disadvantages of its use must be less than the disadvantages of it not being use.

2.3 Allowed foreign materials

At the end of 2007 the material handbook listed 63 allowed materials, 53 in safety level A and 10 in safety level B. All the allowed materials at the end of 2007 are listed in Ta-ble 2 and Table 3. Some materials are not in use anymore, and these have been removed from the material handbook. The required time of the material has been ended or substi-tuting material has been found. In the Table 2 and the Table 3 there are also the name of the manufacturers, afterwards products are named only by trade name. Some materials could be allowed only for short period and these materials are not presented here. Some restrictions may also apply to the use of the allowed materials; for example, materials may only be used for the pur-pose they are designed, i.e. motor oils may only be used in vehicles. Permission to use the material may be in restricted in certain area, e.g. 3-6548 silicone RTV foam can be use only in through holes of electric cables in concrete walls. Table 2. Allowed materials in safety level B in ONKALO 2007 Safety Level B Metals Other Manufacturer Material Manufacturer Material Ørsta Stal AS CT-rock bolt Berner Oy Absodan universal Fundia Deformed reinforcement bar Stanford NA Peel Off China Marker Fibco GmbH Shotcrete fibers CF-03-35 Merck kGaA Fluorescein sodium Tammet Oy Mine net Balerman Oy Chem-Sorb Bekaert Dramix Shotcrete Fibres CC-Company Ikasorb 1030

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Table 3. Allowed materials in ONKALO 2007 in safety level A. Safety Level A Cement, Concrete and additives Organic compounds Manufacturer Material Manufacturer Material Finnsementti Oy Parmix-Silika Shell Donax TA SIKA Mighty 150 Maston Zinc spray Finnsementti Oy Rapid Cement Shell Torcula Finnsementti Oy Super-Parmix Shell Tellus Oil S 68 Rescon Mapei Mapequick AF-2000 Shell Form 5 Finnsementti Oy SR-Cement Exxon Mobil Nuto H32 Cementa Ultrafin 16 (UF-16) Berner Oy Lasol 100 Elkem Grout Aid Shell GlykoShell

Degussa Mastertop 450 Shell Helix Ultra motor oil 5W-40

Shell Spirax AX Shell Grease Centra W AT-tuote AT-marking paint

Shell Retinax Grease HDX2 Nitrogen compounds Shell Rimula X Oil 10W-30 Manufacturer Material Shell Universal Engine Oil Forcit Oy Anite Shell Donax YB brake fluid Forcit Oy Kemix A pipecharge Shell Corena D 46 Forcit Oy Nonel detonators Kärcher RM 110 ASF Ultra

Forcit Oy Kemix A cartridge Almacon Oy Drainage pipe (PE foam)

Forcit Oy F-cord 10 detonating cord Bestolife Co Bestolife 3000

Forcit Oy Kemiitti 810 CRC Industries Sweden AB CRC Brackleen

Forcit Oy Nobel Prime Svenska Statoil Gear Way G5 80 W-90

Gotlands Bioenergi AB Rapsgul

Shell Tellus TX 46 Shell Retinax EP 2 Berner Oy Korrek Coolant G30 Nordic Lubricants Castrol SMX-S

Nordic Lubricants Castrol Response

DOT 4 Nordic Lubricants Castrol TQ Dextron III Inorganic compounds Algol Chemicals Oy Acetic acid Manufacturer Bio Ex SA Bio Ex SA Ecopol Tikkurila Falu Red Ochre paint Shell SRS Grease 4000

Land Rover Swivel Housing Grease

STC 3435

Dow Corning SA 3-6548 silicone RTV foam

Shell Thermo City, winter/summer

KAESER Kompresso-ren GmbH

Sigma Fluid S-460

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2.4 Forbidden foreign materials

At the end of 2007 there were 20 forbidden materials listed and these are presented in Table 4. Any new material was not forbidden in 2007. The forbidden materials were unsuitable for ONKALO conditions and may be harmful for long-term safety. All the suggested material for introduced in ONKALO if not ac-cepted is listed in the forbidden materials list. Reasons for not allowing the use of mate-rial may vary, e.g., if a material contains more harmful components than a similarly functioning substitute, obviously the material containing fewer harmful components will be accepted. Sometimes, a substitute material, which is better for long-term safety, was found. Table 4. Materials forbidden to be used in ONKALO. Name of the material Reason for rejection Finnsementti Perus-Parmix Includes lignosulphate, may be harmful for radionuclide

transport Rescon Mapei Sprut 34 Better alternative found Masterbuilders Rheocem 800T Better alternative found Masterbuilders Rheocem 800SR Better alternative found Masterbuilders Rheobuilt 2000PF Better alternative found Rescon Mapei Mikrocem 800 Better alternative found Rescon Mapei Mikrocem 650 SR Better alternative found Rescon Mapei Mapefluid 400 N Better alternative found Windscreen washing agents Only Lasol allowed Würth marking paint Better alternative found AQUA Master marking paint Better alternative found Marking paint Mercalin RS Better alternative found Tikkurila Oil based red paint Better alternative found Tikkurila Siroplast 2 roofpaint Better alternative found Finnsementti VB-Parmix Includes polycarboxylate, may be harmful for radionuclide

transport Hilti HIT-HY 150 Forbidden in ONKALO design plan Semtu Oy Structuro 111X Includes polycarboxylate, may be harmful for radionuclide

transport CC-Company CC deicing agent Includes chlorides, causes copper corrosion and disturbs

ONKALO monitoring Finnsementti Megacement Better alternative found Würth WIT-C100/200 Includes organic material

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2.5 Quality control

As a part of ONKALO quality control, the use of foreign materials is controlled. Three times a year have been fulfilled an internal auditing. In 2007 these internal auditing has been done in January, September and December. In January there was only slight negli-gence. In September there were more remarks outside the ONKALO tunnel, but no un-declared materials in ONKALO were found. In December these defects were corrected. In October an extra internal auditing has been done specially for the rising boring ma-chine. There was much negligence, for example materials were not approved for use in ONKALO and material safety data sheets were missing. These negligences were cor-rected right away and a nonconformity report was done in Posiva's KELPO data man-agement system. A small (about 5 litres) oil leak had befallen in ONKALO during drilling a pilot hole. All spilled oil was collected away. The acceptance limits for the use of foreign materials have been defined. These limits have been calculated by estimations by Hagros (2007). Instructions have been provided for cases where limits are exceeded and for the application of the CEIC procedure. CEIC procedure has been discussed in Juhola 2005. Migration of foreign materials in groundwater has been monitored in sedimentation pool. All water used in ONKALO is pumped to the surface into sedimentation pool. Residue oil is removed from the water before it enters the sedimentation pool. In sedi-mentation pool is four sampling points and water samples were taken every second week. Results are reported in chapter 4. Also leaking fractures after grouting have been monitored. In 2007 eight samples were taken from leaking structures, fractures or leaking rock boltholes. Results will be re-ported later in 2008.

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3 MATERIALS AND AMOUNTS USED IN ONKALO

Hagros (2007) has re-estimated the quantities of foreign materials remaining in the dif-ferent part of ONKALO and the repository at the time of backfilling. These estimations per excavated cubic meter are included in Tables 5 and 6. The categorization of the materials is similar to the one used in the material handbook. In the following chapters are reported the materials used in ONKALO during 2007.

3.1 Safety level A

3.1.1 Cement, concrete and additives

In the ONKALO tunnel Cementa Ultrafin 16 (UF-16) was used as grouting cement. The additives were Grout Aid and Mighty 150. The amounts are given in Table 5 separately for access tunnel and shafts. In Appendix 1 are presented figures for used amounts per chainage. To avoid high pH cementitious plume, lower pH cement have been developed. Posiva has been developing low-pH (≤11) cement as a joint project between Posiva, SKB and NUMO (Ahokas et al. 2006). In this project Posiva was responsible for developing a low-pH cementitious grout for fractures of hydraulic aperture over 100 μm. Posiva has continued the development work within the R20 programme by further laboratory test-ing and field tests. For grouting in ONKALO low-pH cement was tested four times in 2007. First test was in March at chainage 1880 and the rest of tests were made in shaft. These amounts are including in Table 5 and also in Appendix 1. Results of the low-pH tests are reported in Hollmén (2007). Posiva, SKB, Nagra and NUMO have a joint project to study long-term safety aspects of superplasticizers. The main long-term safety issue of concern is whether the super-plasticizers or other organic additives in cement might affect the transport properties of radionuclides. This project is still ongoing and the final report will be published later in 2008. No plugging was done in 2007. SR-cement was used for soldering anchor and support bolts. These amounts are presented in Table 5. Since 2005 ONKALO has been shotcreted systematically. The material used is SR-cement and the additives used are Mapequick AF2000, Super Parmix and Parmix Silica. The amounts of shotcrete are given in Table 5.

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Table 5. Cementitious materials and additives used in ONKALO. The total amounts

used from the beginning of construction are detailed separately for ONKALO and for

ONKALO including open cut).

Materials

ONKALO 2007 Total ONKALO 2004-2007

Total ONKALO and open cut

ONKALO 2007

Amount Dry

weight Amount Dry

weight Amount Dry

weight Used 2007

Estima-ted

[kg] [kg] [kg] [kg] [kg] [kg] [kg m-3

] [kg m-3

]

Grouting

Cements

Ultrafin16 (tunnel) 6600 378791 398453 0.15 1.41

Ultrafin16 (shafts) 62645 64936 64936

SR-Cement 0 18880 18880

Grouting cement total 69245 462607 482269

Additives

Set Control II 0 3480.4 3740.8

SP-40 0 3176 3241.6

Grout Aid (tunnel) 3196 1598 51946.1 25973.05 51946.1 40413 0.04

Grout Aid (shafts) 28539 14269.5 28880 14440 28880 14440

Mighty150 (tunnel) 185 92.5 2403.4 1201.7 2403.4 1201.7 0.002

Mighty150 (shafts) 1714 857 1714 857 1714 857

Plugging

Cements

Ultrafin16 0 6161 6161

SR-Cement 0 402 402

Rapid-cement 0 0 7122

Plugging cement total 0 6563 13685

Shotcrete

Cements

Megacement 0 0 1290

Rapid-cement 0 29660 29660

SR-Cement 404124 937004 937004 8.90

Shotcrete Total 404124 966664 967954 8.90 6.63

Additives

Structuro 111X 0 1951.6 1951.6

AF2000 15996.8 7998 39052.6 19526.3 39052.6 19526.3 0.35

Parmix Silica 20209 46853 46853 0.44

Super-Parmix 8246.7 3299 11184.6 4474.3 11184.6 4474.3 0.18

Shotcrete additi-ves total 44452.5 99041.8 99041.8 0.98

Cement for anchor and

support bolts

Cements

SR-Cement 6643 19041.5 19041.5 0.15

Rapid-cement 0 0 4251.4

Cement for solders total 6643 19041.5 23292.9 0.15

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3.1.2 Organic compounds

Some of the cement additives can also be organic compounds but these have been clas-sified to the same group with cement. Geological measurement points were marked in ONKALO with AT-marking paint. In 2007 paint was used 186,84 L, the total amount used during construction is 587,6 L. In 2007 laid drainage pipes under shotcrete at chainages 1833, 1835 and between chai-nages 0-6. Measured and certified location drawings are available on Kronodoc, but amounts of these are not available. Earlier there were laid drainage pipes at chainages 170, 236, 290, 300, 460, 463, 590 and 645.

Different kind of organics oils, such as lubricants, anti-freeze solutions and fuel were used in the vehicles in ONKALO. The amounts of these and the amount that probably stayed in ONKALO have not been calculated or estimated in this report.

3.1.3 Nitrogen compounds

Nitrogen compounds are mainly explosives. Explosives manufactured by Forcit Oy were used in the ONKALO tunnel. Mainly bulk-emulsion explosives were used in ONKALO. These bulk-emulsion explosives included Kemiitti 810 as matrix and fumi-gant, and Nobel Prime as bottom charge. Depending of the recipe, also acetic acid could be used. It is a catalyst of blasting and without acetic acid the fumigation of blasting could be incomplete. Amounts of all used explosives are presented in Table 6. Although acetic acid is an or-ganic compound it is also presented in this group. A summary of the explosives used in tunnel in 2007 is provided in Appendix 2. The amounts of explosives per chainage me-ter are given in graphical form. There is personnel shaft access at chainage 1890 and investigation niche at around chainage 2440 as seen in increasing amounts of caps and Kemix-A pipecharges in Ap-pedix 2 Figures 3 and 4. The exhaust air shaft access is at chainage 1940 as seen in in-creasing amounts of bulk-emulsion materials.

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Table 6. Amounts of used explosives in 2007. Estimations are made by Hagros (2007).

Materials [unit]

ONKALO 2007

Total ONKALO 2004-2007

Total ONKALO and open cut

2004-2007 ONKALO 2007

Amount Amount Amount Used 2007 [kg m-3]

Estimated [kg m-3]

Caps [pcs] 31543 94747 95460 0.69 0.6 Cords [m] 27563 29404 Anite [kg] 2401 3728.3 F-pipe [kg] 2399.3 2400.3 Kemix-A cartridge [kg] 6 27545 27545 Kemix-A pipecharge[kg] 5309.0 194128.5 194144.5 0.12 Dynamite [kg] 743.9 Kemiitti 810 matrix [kg] 182654.8 202030.5 202030.5 4.02 Kemiitti 810 fumigant [kg] 2919.2 3319.7 3319.7 0.06

Nobel Prime [kg] 29540.5 32660.5 32660.5 0.65 Explosives total [kg] 220429.4 464484.4 466572.6 4.85 3.0 Acetic Acid 100% [kg] 365.3 374.4 374.4 0.008

3.1.4 Other inorganic compounds

Coordinate measured support bolts have been paint earlier with Falu red ochre paint, but not in year 2007. These were painted with AT-marking paint.

3.2 Safety level B

3.2.1 Metals

Support bolts and hot-dip galvanized reinforcement bars were used for rock reinforce-ment. Support bolts have been made of acid-proof stainless steel (HST) or stainless steel (RST). In 2007 two kinds of shotcrete fibres, Krampe Harex and Dramix were tested. The Dramix fibres were better and will be used also in the future. Used amounts of metal components are reported in Table 7. Stud bolts have been grouted to act as gutter bracket for heating, plumbing and ventila-tion electricity channels. These bolts have different length and exact data have been saved to Posiva's POTTI data management system. Stub bolts for mine net has been grouted in ONKALO between chainages 1585 - 1600. The mine net will be installed later. Measuring weirs have been bolted with minor amount of anchor bolts manufactured by Würth.

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Table 7. Metal component and amounts used in ONKALO in 2007.RST = stainless steel, HST = acid-proof stainless steel, kZn = hot-dip galvanized steel.

2007

Total ONKALO 2004-2007

Total ONKALO + open cut 2004-

2007 Support bolts [pcs]

A500HW HST 25*3000 306 1368 1458 A500HW HST 25*4000 64 308 A500HW HST 25*5000 10 10 12 A500HW HST 32*2500 2 A500HW HST 32*3000 2 A500HW HST 32*4000 21 A500HW HST 32*4500 123 A500HW HST 32*6000 8 62 A500HW RST 25*3000 16 16 16 A500HW HST 16*1000-3000 2077 3442 3442 CT-bolt L3000 kZn 452 790 790 Sormat PFG M10 wedge anchor 200 200 Brass sleeve (150 mm * 28 mm) 3 3

Shotcrete fibres [kg] ZCF-03-35 90 90 Krampe Harex 360.5 360.5 360.5 Dramix 696.5 696.5 696.5

3.2.2 Other materials

Sodium fluorescein has been used for tracer in drilling water. Measurements results of concentration of sodium fluorescein are reported in chapter 4. Used amounts of it hasn’t been reported, almost all of it are sluiced away. Ikasorb 1030 is an absorbent and has been used after oil leak if needed. Used Ikasorb 1030 has been removed from ONKALO and amounts of use were not reported.

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4 MONITORING OF ONKALO CONSTRUCTION

4.1 ONKALO process waters

These results have been earlier reported in Monitoring report of Hydrogeochemistry (Hirvonen and Mäntynen 2005, Hirvonen et al. 2006 and Pitkänen et al. 2007.) All process waters used in ONKALO are pumped from the Korvensuo reservoir. A tracer, sodium fluorescein is added in the water in order to enable identification of the remaining amount of process water in real groundwater samples. The concentration of sodium fluorescein used in process waters is 250 μg/L. The concentration of sodium fluorescein is controlled by regular sampling of process water. In 2007, samples of process water were collected once a week according to Posiva's working instructions. The results of the analyses are presented in Figure 1. So-dium fluorescein concentration in process water has mainly remained close to 200 and 250 μg/L. Higher concentration of sodium fluorescein was found in January. This was due to technical problems with the pump in the Korvensuo reservoir. During the autumn the concentration frequently fell slightly under 200 μg/L (Figure 1). However, it can be concluded that automatic dilution of process waters is reliable enough, but requires con-stant monitoring to ensure that technical problems are detected. Samples from the main solution were taken after sodium fluorescein had been added in the main solution container. The analysis process of the main solution will remain un-changed and process water samples will be taken once a week.

Figure 1. Results of sodium fluorescein analysis of process waters.

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4.2 Sedimentation pool and outlet ditch

All waters used during the excavation of ONKALO are pumped up to the surface into a sedimentation pool after removal of residue oil from the water. From the sedimentation pool the water flows through an outlet pipe to the outlet ditch. The locations of the sedimentation pool, the discharge tube (outlet pipe) and the outlet ditch are presented in Figure 2 with four different measuring points. In addition to the four measuring points, samples have also been taken at the end of the discharge tube. The distance from the discharge tube to the first measuring point (measuring point 1) is approximately 5 m. The second (measuring point 2) is located approximately 100 m and the third (measur-ing point 3) is 200 m away from the discharge tube. The fourth (measuring point 4) is at a distance of about 500 m from the discharge tube.

Figure 2. The location of the sedimentation pool, the outlet pipe and the four measuring points in the outlet ditch. The end of the discharge tube is five meters south of the first measuring point.

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The quality of the water in the sedimentation pool and in the outlet ditch has been moni-tored weekly through pH and Electrical Conductivity (EC) measurements as well as sodium fluorescein analyses. In addition, water samples (Class A water samples) are collected once a month from the sedimentation pool and the outlet ditch according to instructions given in Paaso et al. 2003. The chemical results for the sedimentation pool are shown in Table 8 and for the end of the discharge tube in Table 9. The results of field pH measurements for all sampling points are presented in Figure 4. The pH of the water pumped out has varied from slightly alkaline to highly alkaline in both the sedimentation pool and the outlet ditch, and follows the same pattern as in Pitkänen et al. 2007 (2006 monitoring results of hy-drogeochemistry). Groundwater hydrogeochemistry analyses from ONKALO in 2007 are reported in Pit-känen et al 2008. The chemistry in ONKALO baseline groundwater has been compared to the chemistry in sedimentation pool. The baseline conditions have been reported in Andersson et al 2007. The influence of grouting cement and shotcrete can be seen in the results of pH and conductivity in sedimentation pool. Also the influence of blasting can be seen in NO2, NO3 and N-tot concentrations in sedimentation pool. In baseline condi-tions in ONKALO NO2, NO3 and N-tot concentrations are very low (under 1 mg/l). The NO2, NO3 and N-tot concentrations in sedimentation pool have been presented in Figure 3.

Figure 3. NO2, NO3 and N-tot concentrations in sedimentation pool.

Table 8. Analysis results for water samples taken from sedimentation pool.

pH Conductivity Sodium

fluorescein Density DIC DOC Total alkalinity,

HCl uptake Carbonate alkalinity,

HCl uptake Total acidity, NaOH uptake F Cl Br HCO3

(mS/cm) (μg/l) (g/ml) (mg/l) (mg/l) (mmol/l) (mmol/l) (mmol/l) (mg/l) (mg/l) (mg/l) (mg/l)

7.2.2007 9.0 1.25 160.0 0.998 13.8 8.2 1.77 0.24 - 1.4 167 0.7 108 7.3.2007 11.3 1.39 120.0 0.999 5.8 14.0 3.57 2.68 - 1 176 0.7 218

11.4.2007 8.5 1.35 110.0 1.000 14.0 6.3 1.76 <0.05 - 0.7 138 0.5 107 2.5.2007 9.4 1.08 130.0 0.999 5.6 6.4 1.64 0.65 - 1 105 0.4 100

13.6.2007 8.9 0.65 190.0 0.999 14.1 6.7 1.66 0.3 - 0.9 72.7 0.3 101 2.7.2007 11.5 2.52 40.0 0.999 3.4 14.4 5.58 4.68 - 2 356 1.2 340 1.8.2007 12.0 2.49 50.0 1.000 3.9 9.3 8.55 7.73 - 0.5 158 0.7 522 5.9.2007 10.9 1.17 99.0 1.002 2.7 7.6 2.76 1.99 - 1 140 0.4 168

3.10.2007 9.6 1.47 95.0 1.000 3.4 6.7 2.02 1.24 - 1.7 201 0.9 123 7.11.2007 9.5 0.79 120.0 1.000 6.4 4.8 1.31 0.53 - 0.8 84.3 0.5 80

28.11.2007 9.3 0.84 150.0 - 9.6 5.4 1.44 0.34 - 1.1 95.3 0.5 88

SO4 S-tot NO3 NO2 N-tot Al Na K Ca Mg Mn Fe-tot SiO2 NH4 Solid matter B-tot Sr (mg/l) (mg/l) (mg/l) (mg/l) (mg/l) (mg/l) (mg/l) (mg/l) (mg/l) (mg/l) (mg/l) (mg/l) (mg/l) (mg/l) (mg/l) (mg/l) (mg/l)

7.2.2007 160 53 150 4.7 43 <0.05 144 17.3 62 11.9 0.004 0.032 15.1 15.57 5755.0 0.19 0.52 7.3.2007 103 35 83 4.6 27 <0.05 162 14.5 82 1.9 <0.002 0.003 31.6 10.4 164.0 0.13 0.44

11.4.2007 124 42 240 4.5 83 <0.05 138 16.5 58 11.7 0.016 0.036 9.1 32.1 384.0 0.12 0.43 2.5.2007 111 37 220 5.4 60 <0.05 119 18 58 7.4 <0.002 0.030 11.6 28.48 399.0 0.11 0.35

13.6.2007 74.2 26 54 3.6 18 <0.05 69 7.43 40 6.6 0.004 0.053 12.1 8.413 1450.0 0.10 0.24 2.7.2007 146 49 250 15.0 82 0.12 308 46.7 97 0.4 <0.002 0.003 20.8 28.65 77.0 0.14 1.36 1.8.2007 98.1 33 83 0.1 22 <0.05 143 20.5 193 0.3 <0.002 0.002 13.9 3.271 21.0 0.07 0.58 5.9.2007 98.3 34 110 9.1 47 0.28 136 24.2 68 1.8 <0.002 0.009 22.2 19.17 330.0 0.10 0.57

3.10.2007 141 44 250 12.0 85 <0.05 174 21.8 75 6.0 <0.002 0.017 12.3 35.55 57.0 0.13 0.60 7.11.2007 84 27 94 3.7 31 0.1 84 13.3 39 6.7 <0.002 0.030 9.6 10.86 489.0 0.11 0.31

28.11.2007 118 39 64 2.5 21 <0.05 86 10 41 8.9 0.005 0.022 8.7 8.8515 348.0 0.14 0.30

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Table 9. Analysis for the results for samples taken at the end of discharge tube.

pH Conductivity Sodium

fluorescein DIC DOC Total alkalinity,

HCl uptake Carbonate alkalinity,

HCl uptake Total acidity, NaOH uptake F Cl Br HCO3

(mS/cm) (μg/l) (mg/l) (mg/l) (mmol/l) (mmol/l) (mmol/l) (mg/l) (mg/l) (mg/l) (mg/l) 7.2.2007 8.7 1.58 100.0 22.3 7.4 2.42 0.23 - 1 223 0.9 148 7.3.2007 9.8 1.00 120.0 6.0 9.3 1.43 0.6 - 1 163 0.6 87.2

11.4.2007 8.8 1.64 15.0 13.0 6.9 1.74 0.18 - 0.9 261 0.9 106 2.5.2007 9.4 1.19 35.0 4.0 6.4 1.4 0.59 - 1.3 158 0.6 85.4

13.6.2007 9.8 0.67 140.0 1.8 5.8 1.32 0.83 - 1.1 67.4 0.3 80.5 2.7.2007 11.5 2.23 <1 2.1 17.2 5.21 4.44 - 1.9 248 1 318 1.8.2007 9.9 1.00 31.0 2.9 4.9 1.09 0.5 - 0.9 166 0.8 66.5 5.9.2007 11.7 1.97 12.0 2.7 10.0 5.26 4.4 - 1.1 175 0.6 321

3.10.2007 10.0 1.45 38.0 1.9 6.7 1.97 1.3 - 1.6 200 0.9 120 7.11.2007 9.4 0.96 57.0 5.5 4.6 1.08 0.39 - 0.9 135 0.6 65.9

28.11.2007 9.1 0.85 140.0 10.2 5.3 1.46 0.31 - 1.5 106 0.5 89.1

SO4 S-tot NO3 NO2 N-tot Na K Ca Mg Mn Fe-tot SiO2 NH4 B-tot Sr (mg/l) (mg/l) (mg/l) (mg/l) (mg/l) (mg/l) (mg/l) (mg/l) (mg/l) (mg/l) (mg/l) (mg/l) (mg/l) (mg/l) (mg/l)

7.2.2007 123 41 230 4.5 68 178 17 49.7 12.5 0.006 0.029 11.6 35.28 0.20 0.50 7.3.2007 92.5 31 65 3.9 22 143 13 27.8 7.39 <0.002 0.011 12.3 8.893 0.14 0.35

11.4.2007 126 42 190 7 61 206 18.6 56.4 10.8 0.007 0.036 16.3 23.17 0.17 0.59 2.5.2007 109 36 210 6.4 72 154 20.4 57.6 6.36 0.002 0.014 15.4 23.42 0.25 0.43

13.6.2007 77.7 27 110 4.1 35 72 10.9 38.3 3.46 <0.002 0.017 19.5 15.66 0.09 0.21 2.7.2007 183 62 170 14 50 220 37 130 0.2 <0.002 <0.002 16.2 12.93 0.13 1.50 1.8.2007 112 37 91 0.12 23 137 16.4 49.5 4.22 <0.002 0.007 17.5 4.729 0.13 0.39 5.9.2007 118 40 120 13 43 165 29.7 122 0.19 <0.002 0.008 21 13.31 0.08 0.99

3.10.2007 151 47 230 12 76 172 23.6 84.6 4.66 0.002 0.015 14.4 26.83 0.12 0.70 7.11.2007 117 37 70 4.5 22 111 13.6 48 7.45 0.004 0.010 11.8 5.82 0.42 0.13

28.11.2007 112 38 64 3.4 26 97 11.6 40.1 8.09 0.009 0.017 9.25 9.726 0.15 0.31

18

19

Figure 4. Results of field pH measurements for the sedimentation pool, the end of the discharge tube and the open ditch (measuring points 1 to 4). Measuring points have been presented in Figure 2. As seen in Figure 4, the highest pH values were measured in the sedimentation, in the outlet ditch and in measuring place 1. The pH values primarily fluctuate between 5 and 12. The high pH values are the result of grouting and shotcreting in ONKALO. In the ditch, pH decreased below neutral and was weakly acid a few times during the year. This decrease occurred due to heavy rain in January and November and there were no grouting and shotcreting operations at that time. The quality of water in the sedimentation pool and in the outlet ditch was monitored normally in whole year 2007. However, the pH reached a value of over 12 in sedimenta-tion pool due to shotcreting and grouting and decreased below 11 quite soon after that. The shotcreting in the ONKALO tunnel in 2007 was a continuous process and a lot of cement was used. So far the high pH values have not constituted a risk to the environ-ment, because high pH values are neutralized soon after the water reaches the ditch (measuring point 4 in Figure 4).

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Figure 5. Results of EC measurement in the sedimentation pool and at the end of the discharge tube in 2007.

Figure 6. Results of sodium fluorescein analyses in the sedimentation pool and at the end of discharge tube in 2007.

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The EC values of water have varied in the sedimentation pool but been more stable in the ditch (Figure 5). The highest EC in the sedimentation pool (778 mS/m) was meas-ured on 28 June 2007 (corresponding to the high pH value at the same time) and in the outlet ditch (282 mS/m) on same date. Also there were some high values (377 - 417 mS/cm) in October in sedimentation pool due to shotcreting. As a rule, EC results for the sedimentation pool and the outlet ditch remained between 30-270 mS/m. The amount of groundwater from the ONKALO tunnel still plays a minor role in the total amount of water pumped out, because the process waters mix with groundwater. The total volume of leaking groundwater was about 1.4 L/min/100m at the end of December 2007, when the tunnel was 2576 m long. Figure 6 shows the sodium fluorescein results for the sedimentation pool and the end of the discharge tube. Sodium fluorescein decomposes under the influence of UV light, so the tracer soon looses its concentration, when the water reaches the open ditch. The an-nual rhythm can be seen in these results; in winter when is less UV light, sodium fluo-rescein results are higher. In 2007 Class A samples, aluminium and density have been collected from both the sedimentation pool and the outlet ditch once a month. Also solid matter samples have been collected from the sedimentation pool. The sampling pro-gramme will continue with one sampling per month.

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5 DISCUSSION

The most common foreign material in ONKALO is cement and its additives. In 2007 ONKALO access tunnel was grouted only at three places. Both existing shafts, the per-sonnel shaft (access at chainage 915) and the exhaust air shaft (access at chainage 980) were grouted with UF-16 cement. Furthermore cement has been used in shotcreting and for support and anchor bolts. The shotcrete amounts are 25 % greater than estimated. Migration of foreign materials in groundwater has been monitored in sedimentation pool and in outlet ditch. All water used in ONKALO is pumped to the surface into se-dimentation pool. The pH in sedimentation pool and in outlet ditch varies between 8 and 12.5 due to grouting or shotcreting. Also some gain in conductivity could be seen due to grouting and shotcreting. The use of blasting materials can be seen in sedimentation pool as a increasing of NO2, NO3 and N-tot concentrations.

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REFERENCES

Andersson, J., Ahokas, H., Hudson, J., Koskinen, L., Luukkonen, A., Löfman, J., Keto, V., Pitkänen, P., Mattila, J., Ikonen, A.T.K. and Ylä-Mella, M. 2007. Olkiluoto site description 2006. Posiva Report 2007-03. Ahokas, H., Ahokas, T., Hansen, J., Hellä, P., Lehtinen, A., Koskinen, K., Koskinen, L., Löfman, J. Marcos, N., Meszaros, F., Partamies, S., Pitkänen, P., Sievänen, U., Snell-man, M. and Vieno, T. 2006. Control of water inflow and use of cement in ONKALO after penetration of fracture zone R19. Posiva Working Report 2006-45. Hagros, A. 2007. Foreign Materials in the Repository - Update of Estimated Quantities. Posiva Working Report 2007-17. Hirvonen, H. and Mäntynen, M. 2005. Results of monitoring at Olkiluoto in 2004, Geo-chemistry. Posiva Working Report 2005-77. Hirvonen, H., Lehtinen, A. and Hatanpää, E. 2006. Results of monitoring at Olkiluoto in 2005, Geochemistry. Posiva Working Report 2006-67. Hjerpe, T. 2003. Engineered and stray materials in the underground rock characterisa-tion facility ONKALO – Estimation of quantities at the time of the backfilling. Posiva Working Report 2003-48. Hollmén, K. 2007. R20 Programme: The Development of Grouting Technique in ONKALO. Posiva Working Report 2007-101. Juhola, P. 2005. Results of Monitoring at Olkiluoto in 2004, Foreign Materials. Posiva Working Report 2005-25. Juhola, P. 2007. Results of Monitoring at Olkiluoto in 2006, Foreign Materials. Posiva Working Report 2007-54. Paaso, N. (ed.), Mäntynen, M., Vepsäläinen, A. and Laakso, T. 2003. Posivan vesinäyt-teenoton kenttätyöohje, Rev.3, Posiva Työraportti 2003-02 (abstract in English). Pitkänen, P., Partamies, S., Lahdenperä, A.M., Lehtinen, A., Ahokas, T., Hirvonen, H. and Hatanpää, E. 2007. Results of Monitoring at Olkiluoto in 2006, Hydrogeochemistry. Posiva Working Report 2007-51. Pitkänen, P., Partamies, S., Lahdenperä, A-M., Penttinen, T., Lehtinen, A., Hirvonen, H., Lamminmäki, T., Hatanpää, E. 2008. Results of monitoring at Olkiluoto in 2007, Hydrogeochemistry. Posiva Working Report 2008-24. Posiva Oy. 2003. Programme of monitoring at Olkiluoto during construction and opera-tion of the ONKALO. Posiva 2003-05.

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Saanio, T., Kirkkomäki, T., Keto, P., Kukkola, T. and Raiko, H. 2006. Loppusijoitusti-lojen esisuunnitelma – Vaihe 2. Posiva Working Report 2006-93. (in Finnish). Vieno T., Lehikoinen J., Löfman J., Nordman H. and Mészáros F. 2003. Assessment of disturbances caused by construction and operation of ONKALO. Posiva 2003-06. Vuorio, M. 2006. Results of Monitoring at Olkiluoto in 2005, Foreign Materials. Posiva Working Report 2006-58.

APPENDIX 1

Figure 1. Grouting cements in ONKALO in 2007 used per chainage. There are shafts at chainage 915 and 980.

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Figure 2. Additives in grouting cement per chainage used in ONKALO in 2007. Note two Y-axels.

26

APPENDIX 2

Figure 3. Caps amounts per chainage used in ONKALO 2007. There is personnel shaft access at chainage 1890.

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Figure 4. Kemix-A Cartridge and pipecharge amounts used per chainage in 2007. Kemix-A cartridge have been used only once at chainage 2196.

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Figure 5. The amounts of Kemiitti 810 matrix and Fumigant. Note two Y-axels. At chainage 1890 the amounts of Matrix is 6943 kg and fumigant 104 kg. At chainage 1940 the amount of matrix is 4208 kg and fumigant 70 kg.

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Figure 6. The amounts of Pendex bottom charge and acetic acid per chainage. Note two Y-axels. At chainage 1890 the amounts of Pendex are 1146 kg and acetic acid 13.9 kg. At chainage 1940 the amounts of Pendex are 709 kg and acetic acid 8.4 kg.

30