Cross-checking against the Swedish SR-Site 29

5 CROSS-CHECKING AGAINST OTHER RELEVANT FEP SOURCES 29

5.1 Cross-checking against the Swedish SR-Site 29

The SR-Site FEP catalogue (SKB 2010a) has been mapped to TURVA-2012 FEPs in

Appendix C to check the comprehensiveness of the TURVA-2012 FEP list. All SR-Site

FEPs that could not be mapped directly to any TURVA-2012 FEP are shown in Table

5-1. It came out that the FEP lists are fairly similar with the few exceptions mentioned

in Table 5-1. Differences are mainly due to the fact that assessment methodology issues

(including quality control issues) are not treated as FEPs in TURVA-2012 but are han-

dled elsewhere in the safety case and/or in other documents presented for the construc-

tion licence application (CLA). Also, a few irrelevant FEPs (e.g. earth currents, lique-

faction of bentonite) have been excluded from Posiva’s FEP list already before

TURVA-2012, but they are included in the SR-Site FEP catalogue, even if concluded to

be irrelevant in the assessment.

Table 5-1. SR-Site FEPs (SKB 2010a, Tables 5-1...5-12, Sections 5.6, 5.7 and 5.8 and

Appendix 2) that were not found in the TURVA-2012 FEP list (see Table C-1). FEPs

that were excluded from the SR-Site assessment (shown in grey in Table C-1) are not

included here, nor any surface environment FEPs.

FEP

number in

SR-Site

FEP name in SR-Site

Note

ISGen02

Effects of phased op-

eration

Operation schedule is handled elsewhere in TURVA-2012 (e.g. waste emplacement schedule used in thermal dimensioning).

ISGen03

Incomplete closure

Out of the scope of the post-closure safety case TURVA-2012 that

assumes the disposal facility to be properly closed.

ISC01

Mishaps – canister

Canister handling accidents discussed in Performance Assess-

ment but not included as a FEP, as any canister damaged during

operation is assumed to be replaced. Operational safety is outside

the scope of TURVA-2012.

ISC02

Design deviations –

canister

Initial penetrating defect(s) assumed in several radionuclide re-lease scenarios.

ISBu01

Mishaps – buffer

Out of scope of TURVA-2012. It is assumed that quality control

(QC) measures are successfully applied to buffer production and

emplacement. QC issues are related to assessment methodology

and are handled elsewhere in TURVA-2012.

ISBu02

Design deviations –

buffer

Out of scope of TURVA-2012. It is assumed that quality control

(QC) measures are successfully applied to buffer production and

emplacement. QC issues are related to assessment methodology

and are handled elsewhere in TURVA-2012.

ISBfT01

Mishaps – backfill in

tunnels

Out of scope of TURVA-2012. It is assumed that quality control

(QC) measures are successfully applied to backfill production and

emplacement. QC issues are related to assessment methodology

and are handled elsewhere in TURVA-2012.

ISBfT02

Design deviations –

backfill in tunnels

Out of scope of TURVA-2012. It is assumed that quality control (QC) measures are successfully applied to backfill production and

emplacement. QC issues are related to assessment methodology

and are handled elsewhere in TURVA-2012.

ISBP01

Mishaps – bottom plate

in deposition holes

The bottom plate is not a component in Posiva’s current repository design.

ISBP02

Design deviations –

bottom plate in deposi-

tion holes

The bottom plate is not a component in Posiva’s current repository

design.

ISPg01

Mishaps – plugs

Out of scope of TURVA-2012. It is assumed that quality control

(QC) measures are successfully applied to the production and

emplacement of closure plugs (auxiliary components). QC issues

are related to assessment methodology and are handled else-

where in TURVA-2012.

ISPg02

Design deviations –

plugs

Out of scope of TURVA-2012. It is assumed that quality control

(QC) measures are successfully applied to the production and

emplacement of closure plugs (auxiliary components). QC issues

are related to assessment methodology and are handled else-

where in TURVA-2012.

ISCA01

Mishaps – central area

Out of scope of TURVA-2012. It is assumed that quality control

(QC) measures are successfully applied to the selection, produc-

tion and emplacement of closure materials and structures. QC

issues are related to assessment methodology and are handled

elsewhere in TURVA-2012.

ISCA02

Design deviations –

central area

Out of scope of TURVA-2012. It is assumed that quality control (QC) measures are successfully applied to the emplacement of

closure materials and structures. QC issues are related to as-

sessment methodology and are handled elsewhere in TURVA-

2012.

ISTS01 Mishaps/Design devia-

tions – top seal

Out of scope of TURVA-2012. It is assumed that quality control

(QC) measures are successfully applied to the emplacement of

closure materials and structures. QC issues are related to as-

sessment methodology and are handled elsewhere in TURVA-

2012.

ISBhS01 Mishaps/Design devia-

tions – borehole seals

Out of scope of TURVA-2012. It is assumed that quality control

(QC) measures are successfully applied to the emplacement of

borehole seals. QC issues are related to assessment methodology

and are handled elsewhere in TURVA-2012.

F06

Mechanical cladding

failure

Not a FEP in itself in TURVA-2012, but the potential consequence _{of other FEPs, such as e.g. 3.2.7, 4.2.3.}

C13

Earth currents – stray

current corrosion

Excluded already in Posiva’s previous Process Report (Miller & _{Marcos 2007) because the FEP had insignificant consequences}

as reported in SR-Can.

Bu09 Liquefaction

_{Not relevant. Disregarded also in SR-Site since liquefaction from a}

short pulse cannot occur in a high density bentonite, due to high

effective stresses (SKB 2010b, Table 2-4).

BfT08 Liquefaction

_{Not relevant. Disregarded also in SR-Site as not relevant (SKB}

2010b, Table 2-9).

BfT17

Radiation-induced

transformations

Not a relevant FEP for backfill. Radiation effects on backfill proper-_{ties were disregarded also in SR-Site (SKB 2010a, p. 132).}

Ge05

Displacements in intact

rock

Not a specific FEP, but taken into account in the modelled rock _properties.

Ge09

Surface weathering and

erosion

Erosion is discussed in Complementary Considerations in Section _{7.5. Surface weathering effects are considered in the geological}

model of the Olkiluoto site.

In SR-Site this FEP has been moved under Climate and Bio-

sphere (SKB 2010a, Section 4.1.5).

Ge22

Radiation effects (rock

and grout)

Radiation effects are not significant in the geosphere. They were _{disregarded also in SR-Site because of too low radiation fluxes}

(SKB 2010c, Table 1-4).

Ge23 Earth currents

_{Not relevant. Disregarded also in SR-Site since expected electrical}

potential fields are too small to affect groundwater flow or solute

transport (SKB 2010c, Table 1-4).

Pg08,

CA08,

TS08,

BhS08

Liquefaction

Not relevant. Disregarded also in SR-Site, since impact is low (in

central area backfill) or cannot occur at all (in other components)

(SKB 2010b, Tables 2-14 and 2-16).

VarBu08 Stress state

_{Taken into account in 5.2.2, but not a feature of the buffer in itself.}

VarBfT07 Stress state

_{Taken into account in 6.2.2, but not a feature of the backfill in}

itself.

VarPg07 Stress state

_{Will vary according to water uptake and swelling in the clay com-}

ponents of the plugs.

VarCA07 Stress state

_{Will vary according to water uptake and swelling in the clay com-}

ponents of the central areas.

Cli04

Climate system – Cli-

mate in Sweden and

Forsmark

Climate in Finland and at Olkiluoto is considered (10.2.1).

LSGe01

Mechanical evolution of

the Shield

Not included as a specific FEP because the tectonic situation in

the Olkiluoto area is very likely to be stable in the one million year

assessment time frame (post-glacial earthquake effects consid-

ered in FEP 8.2.3 and in the RS and RS-DIL scenarios).

FHA01 General considerations _{Not a FEP in itself, but relates to assessment methodology (pro-}

jected to the near future).

FHA02

Societal analysis, con-

sidered societal as-

pects

Not a FEP in itself, but relates to assessment methodology (pro-

jected to the near future).

FHA03

Technical analysis,

general aspects

Not a FEP in itself, but relates to assessment methodology (pro-_{jected to the near future).}

SiteFact02 Construction of nearby

rock facilities

Taken into account in the site selection process. Dealt with else-

where in the construction licence application (CLA) – also in

Olkiluoto Site Descriptive model (OSD).

SiteFact03 Nearby nuclear power

plant

Taken into account in the site selection process. Dealt with else-

where in the CLA.

SiteFact04 Mine excavation

Taken into account in the site selection process. Dealt with else-

where in the CLA – also OSD.

Meth01

Assessment basis

Related to assessment methodology and thus handled elsewhere

in TURVA-2012.

Meth02 Assessment methodol-

ogy

Assessment methodology is handled elsewhere in TURVA-2012.

The mapping of TURVA-2012 process FEPs to SR-Site process FEPs (Table C-2 in

Appendix C) revealed that all TURVA-2012 process FEPs can be directly mapped to

SR-Site FEPs, indicating that the TURVA-2012 FEP list includes only processes that

are considered relevant also in SR-Site.

In document Safety Case for the Disposal of Spent Nuclear Fuel at Olkiluoto (Page 35-38)