site investigation from desktop to in-situ...

SKB Site Investigation Oskarshamn

Site investigation – From desktop to in-situ

studies

Peter Wikberg

Swedish Nuclear Fuel and Waste Management

Company (SKB)

1


• With varying opinions about nuclear power.

• Put pressure on the industry to solve the waste issue.

• Create a financing system with clear responsibilities between state and the industry.

• Linked to the operation of NPP.

SKB trough history New government 1976


• Theory and practice

• Academy and industry

SKB trough history It all started 35 years ago

The International Stripa mine project 1980-1992 (started 1977)

The 1983 KBS-3 concept


KBS-3, assessment of the long-term safety for disposal

of spent nuclear fuel

• In 1976 the Swedish Government stipulted a law requiring safe handling of nuclear waste

• Desktop studies of disposal options and systems (KBS-1 and KBS-2)

• KBS-3 was based on additional research and geoscientific field data

• Accepted in 1984 by the Swedish Gorvernment as evidence for safe disposal of radioactive waste from nuclear power plants

• KBS-3 was highly appreciated world-wide because of its completeness and the use of both natural and man-made safety barriers

• Ever since the Swedish Nuclear Fuel and Waste Management Company (SKB) is responsible for the continuing efforts needed to license, construct and operate nuclear waste repositories


The KBS-3 concept 1983


The KBS-3 method

Fuel pellet of uranium dioxide Spent

nuclear fuel

Cladding tube

Copper canister with cast-iron

insert

Bedrock

Bentonite clay

Final repository for spent nuclear fuel

BWR fuel assemblies

SKB Site Investigation Oskarshamn R&D

1986

R&D

1989

RD&D

1992

RD&D

1995

RD&D

1998

R&D programme – 89

• Comparison between the

KBS-3 method and one called

WP-Cave

• Plans for a new long-term

safety assessment, SKB 91

RD&D programme- 95

• Encapsulation project

• Deep repository project

• Scheme for reporting of

safety assessments, SR -97

RD&D programme - 92

• Start of planning the

repository for spent

nuclear fuel

• Start of locating the

repository

R&D programme – 86

• Presentation of plans

for an underground

research laboratory,

the Äspö Hard Rock

Laboratory

SKB -91 safety

assessment • Varying geological conditions Reliance

on engineered barriers

RD&D programme - 98

Presented :

• Outcome of locating

studies and criteria for

site selection

• System analysis

SR -97 safety assessment

• Using field date from three

different sites

• All three would meet the

safety criteria put up by the

regulator

SKB:s research and development programme is

stipulated by the law


RD&D

2001

RD&D

2004

RD&D

2010

RD&D programme - 04

• Fullscale tests at the

Äspö- and at the

enkapsulation labs

RD&D programme-10

• Focus on issues for

low- and

intermediate level

waste disposal

RD&D programme -01

• Focus on research

issues related to

technical development

and long- term safety

assessment

RD&D

2007

SR–Can • Preliminary long-term

safety assessment of a


nuclear fuel located in

Forsmark and Laxemar

SR–Site • Safety assessment of the

final repository for spent

nuclear fuel in Forsmark

• Part of the licence

application

RD&D programme -07

• Measures needed to

apply for the license to

construct the


nuclear fuel

SKB:s research and development programme cont.


9

Overview of the site investigation phase

2002-2009

• Investigations performed

• Methods used

• Quality assurance aspects

• Monitoring programme

Karl-Erik Almén

October 6, 2009


The site investigations performed

• Two site investigations were

performed

– Forsmark

– Oskarshamn

(Simpevarp/Laxemar)

• The investigation programme

were similar, and performed in

parallell

• Presented examples are

mostly from

Simpevarp/Laxemar


11

The main activity ”Investigations”

- Characterization of the geosphere and the biosphere

The work at each site was divided in two main groups:

• Investigation; producing primary data

• Site modelling; producing site descriptions


12

The programme development 1

• An important issue for the programme

development was to specify what

information/data is needed

• The information/data users were

– Safety assessment (long term safety)

– Design and enginering (layout , stability)

– Environmental Impact statement

– ”General (geoscientific) understanding”

• Strategies

– dividing the task in diciplines,

– performance in a step-wise procedure,

– integration between diciplines,

– interaction with the data/model users


13

The programme development 2

• Investigation methods feasible for

collecting data and for testing rock

properties were selected, and further

developed when needed

• Extensive experiences from earlier site investigations, mainly

– Study site investigations; 1977-1986

– Stripa projects; 1977-1991

– Äspö Hard Rock Laboratory; 1986- , pre-investigation, construction and experiental phase

• An appropriate sequence of activities were

compiled to a generic investigation

programme (TR-01-29)

• After selection of candidate sites, the

programme was adapted to site specific

programmes (R-01-42, R-01-44 (swedish))


Some information of importance for the

characterisation Geology

• Rock type (distribution and properties)

• Major deformation zones, dividing the rock mass into rock blocks

(occurence and character)

• Fracturing within the rock blocks (frequency and character)

Rock mechanics and thermal properties

• Properties of intact rock and fractures

• Rock stress (magnitude and orientation)

• Thermal conductivity

Hydrogeology

• Hydraulic conductivity of rock mass

• Transmissivity of deformation zones

• Interaction between bedrock and soil

Hydrogeochemistry

• Water chemistry

• Fracture minerals

Transport properties 14


15


16


17

Data flow and sub-organisation in diciplines

Co

nd

ucte

d b

y

the s

ite p

roje

ct

Co

nd

ucte

d b

y t

he

mo

dellin

g p

roje

ct


18

Components of a site investigation; our view before start


19

Organisation

• Deep Repository project

• Subprojects

– Site investigation in Oskarshamn

– Site investigation in Forsmark

– Site Modelling

– Safety assessment

– Repository design

– EIA

• Site investigatioin technology (support)

• Data management

• Project staff


20

The local organisation at the two sites

• Site manager

• Investigations (site organisation)

– Investigation manager

– Assistant investigatioin manager

– Activity leaders (8 subject areas)

– Assistant activity leaders (approx 4)

– Infra structure manager

– Drilling and field coordinators (approx 6)

– Scienific experts (2x0.5)

– Sicada data operator

– GIS operator

– RVS/WellCAD operator (3-D modelling)

– Project time planning

– Secretary

• Site representative repository design

• Site representative EIA

• Information

• Project staff

The site organisation produces

the Primary data

Roles:

SKB (Site organisation)

• Planning

• Contracting

• Reviewing the execution

• Controlling data delivery

Contractors

• Executes investigations

according to controlling

documents

• Deliver primary data

• Responsible for data quality


21


Supporting system

(beside the tools for investigations)

• The database system (Sicada)

– An important tool for storing and controlled distribution

of quality assured data

– Only data from the database are allowed for use in the

modelling work

• Rock visualisation system (RVS);

– a CAD-based system for 3-D modelling and visualisation

of bedrock

• System for organisation and storing of models

• Hydro Monitoring System (HMS);

– for measurements, data organisation and quality control

of all groundwater monitoring data

22


23

Archive

SICADA

Registration and data storage in SICADA

Activity

Descriptive data

Data

Digital archive


24

The site investigation in

Oskarshamn

• The candidate area

- the Simpevarp penninsula

- the large area to the west


25

Initial site investigation

Oskarshamn

The regional area

• Airborne photography

• Airborne geophysics (autumn 2002)

(mag. EM, Radiometric, VLF)

• Vegetation and biotope mapping

• Bird and mammal survey

• Surface water characterisation for ecosystem and

chemistry (lakes, shallow brackish waters, etc)

• Private well inventory

• Hydrologic mapping and initiating measuring stations

(runoff data, recharge and discharge areas)

• Marine geological investigations (seismic, sonar and side-

scanning sonar, sampling)

• GPS measurements

• Seismological network


26

Initial site investigation (ISI) Simpevarp

The Simpevarp penninsula – ISI at the Simpevarp subarea

• The subarea already defined

(approx 5 km2)

• Soil and bedrock mapping

• Drilling of 4 deep cored holes, start

in October 2002

(1 hole from before the SI)

• Drilling of a few percussion drilled

holes

• Monitoring started

• Lineament identification

• Reflection seismics performed

• It was later decided ( autumn 2004)

to not continue with CSI at the

Simpevarp subarea


27

Initial site investigation (ISI) Oskarshamn

The large area in the western part, substep 1

The aim was to select a subarea

• Regional area approx 60 km2

• Mainly based on airborne photo

(terrain model) and geophysics

(next slide)

• Brief geological field control

• Identification of major lineaments

(potential major deformation zones)

and amount of minor lineamnets

within rock areas.

• Identification of homogenious rock

volumes (lithology and structures)


28

Delineation of possible rock volumes

and selection of the Laxemar subarea

Airborn magnetic results Terrain model

(from airborne photo)

As no rock volume was significant more feasible, based on

the geological study performed, the subarea close to the

Simpevarp was selected, early 2003 (approx. 10 km2)


29

The two subareas

Subarea Laxemar

Subarea Simpevarp


30

Initial site investigation, substep 2

at the Laxemar subarea

• Reflection seismics performed for

identific. of (subhorisontal) fracture

zones at depth

• 3 deep (ca 1000m) cored boreholes

were drilled, started February 2004

(2 deep holes from before the SI)

• Soil and bedrock mapping

performed

• Number of percussio n holes drilled

• Initiate long-term monitoring of

seismic movements and deep

groundwater

• Primary data stored in data freeze

1.2

• Decided to continue with complete

site investigation


31

The steps of area reduction and focussing


32

Bedrock map of the Laxemar-Simpevarp area Rock types and major deformations zones

Mainly based om surface mapping


33

Result from detailed magnetic survey


34

Minor lineament / potential minor deformation zones


35

Laxemar 3-D rock domain model (early version)

Generalisation of rock type distribution


36

EW02A

EW007A

Laxemar 3-D deformation zone model (early version)

Generalisation of major deformationn zones


37

Aims for boreholes

• General aims during the Complete Site Investigation

– Characterisation of possible deposition areas

• Rock mass properties including minor deformation

zones

– Identification and characterisation of major deformation

zones (separating rock mass volumes)

– Characterisation of central areas and access ramp areas

• Special programmes (examples):

– DFN programmes; Detailed fracture mapping and

specific oriented borehole groups, for DFN modelling

data supply

– MDZ (minor deformation zones) programme;

Identification and characterisation of these objects,

excavation and shallow drilling


38

Cored boreholes

• Infra structure work

– Access road and drill site

– Electrical supply (network)

– Drill water supply (from percussion borehole)

– Return water handling

• Wire-line tripple tube core drilling, 76 mm diameter

• Drilling Monitoring System; drilling and water parameters

• Hydraulic tests every 100 m, and water sampling if possible

• Groundwater level responses in existing observation holes


39

Drilling sites and machines

• Core drilling

• Percussion drilling


40

Typical investigation programme

in a cored borehole, after drilling • Hydrochemical logging

• Geophysical logging

• BIPS-logging (optical video)

• Borehole radar

• Boremap logging (using BIPS and core)

• Geological single hole interpretation

• Difference flow logging

• Hydraulic injection test

• Selected holes:

– Rock stress measurements (Overcoring and Hydraulic fracturing)

– Complete chemical characterisation

– Ground water flow measurements

– SWIW

– Interference tests

• Sampling for amount of lab analyses

• Groundwater monitoring (long term)


41

TV-loggning with BIP System


42

Drillcore

Boremap logging

• Core logging method based on BIPS

images and core inspection

• rock type

• fractures


43

Hydraulic tests

• Pumpung tests

during drilling

• Hydraulic injection

tests (100m, 25m and

5 m scale)

• Difference flow

logging (next slide)

• Single hole pumping

tests

• Interference pumping

tests, with

observation of

responses


44

Example of hydro tests; Difference flow logging


45

Example of results:

• Geology

(Boremap data)

• Hydraulic

conductivity

(injection test

results)


46

Hydrogeochemistry

• Characterisation of

percipitation, surface,

sediment and soil water

• Sampling during drilling and

pumping tests

• Hydrochemical logging

• Complete characterisation

– in-situ pH, Eh, etc

– extensive analyses in SKB

field laboratory and at

external labs

• Long-term monitoring

• Fracture mineral

characterisation


47

Total number of boreholes at Laxemar

Cored boreholes

• (red holes)

• 2 old holes; 1100m

and 1700m

• 12 holes 800-1000m

• 8 holes 200-800m

• 27 holes 50-200m

• in total 46 holes

• Approx.18 km of

drillcore has been

mapped

Percussion drilled holes

• (blue holes)

• in total 43 holes

• lengths 50-200m


Documentation

• The investigations during ISI and CSI were performed as

subprojects (activities), within the framwork of the site

organisation

• In total approx. 650 subprojects were conducted at each site

Documentation:

• Project documentation as activity plans, quality control

protocols

• Technical reports of the investigation and result, in total

approx. 650 P-reports primary data reports from each site.

• Numbers of data evaluation reports from the modellig work,

R-reports and TR-reports.

• ”Top documentation” of results is the final SDM-report, one

from each site

48


49

Site models/site descriptions is the final

results from the investigations


Modelling results at Forsmark,

the selected site

Indata for the design studies

50

Rock domain model Deformation zone model


Available deposition areas and

preliminary layout of a repository

in Forsmark

51


52

Monitoring programme Monitoring or Long term observations:

• Repeated measurements of a selected number of geological

and biological objects (next page)

• The primary aim was to determine the undisturbed site

conditions (natural variations);

- to establish ”a baseline” before start of the construction of

the repository

• The groundwater monitoring system was also used for

measuring responses during the hydraulic interference tests

• The observations started early during the site investigations,

first a limited number of observation objects, gradually

increasing during the period.

• The monitoring programme will continue at the selected site

Forsmark,

• For the Laxemar site, only part of the monitoring will continue,

now within the Äspö Hard Rock Laboratory programme


53

Monitoring programme

1 Seismic monitoring

(continuously)

• National monitoring

nework, run by the

Uppsala University, with

one station close to each

site

2 Surface ecosystem

(once every year)

• red-listed birds

• elk (population and

reproduction)


54

Monitoring programme 3 Meteorology (mean value of registrations every second)

• precipitation, wind speed and direction,

temperature, etc

4 Winter parameter (observations)

• snow depth, ice cover, frost in ground

5 Hydrology (17 stations, every 1-2 hour)

• water levels in lakes and sea

• water flow in streams


55

Water temperature

0

2

4

6

8

10

12

14

16

18

20

22

2007-0

1-0

1

2007-0

1-2

1

2007-0

2-1

1

2007-0

3-0

4

2007-0

3-2

5

2007-0

4-1

5

2007-0

5-0

6

2007-0

5-2

6

2007-0

6-1

6

2007-0

7-0

7

2007-0

7-2

8

2007-0

8-1

8

Date

Tem

pera

ture

(°C

)

PSM000353 PSM000364 PSM000368

Discharge at station PSM000364 and PSM000368

0.0

0.5

1.0

1.5

2.0

2.5

2007-0

1-0

1

2007-0

1-2

1

2007-0

2-1

1

2007-0

3-0

4

2007-0

3-2

5

2007-0

4-1

5

2007-0

5-0

6

2007-0

5-2

6

2007-0

6-1

6

2007-0

7-0

7

2007-0

7-2

8

2007-0

8-1

8

Date

Dis

ch

arg

e (

m3/s

)

PSM000364 PSM000368

Example of

hydrological data

Water temperature

3 stations

Discharge

2 stations


56

Monitoring programme 6 Hydrogeology

• Groundwater levels and pressures (every minute)

- 70 soil pipes,

- 40 wells in shallow (50-200m) boreholes (75 sections)

- 38 deep boreholes (200 sections)

• Groundwater flow through isolated borehole sections ,

(once every year, varying number of sections)

7 Hydrochemistry (water sampling and analyses)

• precipitation water, surface water (10 points, every

second month)

• groundwater (twice per year)

– near surface groundwater (8 pipes),

– groundwater in bedrock (12 borehole section, varying

between years)


57

System for ground water monitoring in boreholes

Section för groundwater

pressure measurement Section also for

water sampling and

flow measurement


58

System for ground water monitoring in boreholes

Section för groundwater

pressure measurement Section also for

water sampling and

flow measurement

Measurement of in-situ

groundwater flow


59

Groundwater monitoring installations

in the deep cored holes 2008 -- 2009 --

Borehole O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D

KLX01

KLX02

KLX03

KLX04

KLX05

KLX06

KLX07A

KLX07B

KLX08

KLX09

KLX10

KLX11A

KLX12A

KLX13A

KLX14A

KLX15A

KLX16A

KLX17A

KLX18A

KLX19A

KLX20A

KLX21B

KLX27A

Temporary monitoring

Permanent monitoring

2004 2005 2006 2007

site investigation from desktop to in-situ...

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