Backfill Design 2012 - BACKFILL DESIGN 2012 Tiivistelmأ¤ – Abstract This report describes both the

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  • POSIVA 2012-15

    December 2013

    POSIVA OY

    Olki luoto

    FI-27160 EURAJOKI, F INLAND

    Phone (02) 8372 31 (nat. ) , (+358-2-) 8372 31 ( int. )

    Fax (02) 8372 3809 (nat. ) , (+358-2-) 8372 3809 ( int. )

    Jorma Autio

    Md. Mamunul Hassan

    Petri ikka Karttunen

    Paula Keto

    B+Tech Oy

    Backfill Design 2012

  • ISBN 978-951-652-196-4 ISSN 1239-3096

  • Tekijä(t) – Author(s) Jorma Autio, Md. Mamunul Hassan, Petriikka Karttunen, Paula Keto, B+Tech Oy

    Toimeksiantaja(t) – Commissioned by

    Posiva Oy

    Nimeke – Title BACKFILL DESIGN 2012 Tiivistelmä – Abstract

    This report describes both the concept and the detailed design of backfilling in KBS-3V deposition tunnels. The purpose of the backfill is to keep the buffer in place, maintain favourable and predictable conditions for the buffer and the canister, and also favourable rock mechanical, hydrological and geochemical conditions in the near-field and to retard the transport of released radionuclides in case of canister failure. In addition to the description of the overall backfill design, detailed designs for the components of the backfill (foundation, block and pellet fill) are provided in this report. The deposition tunnel end plug design is not presented in this document. In the backfill design, the deposition tunnels are to be filled with a foundation layer material, precompacted clay blocks and extruded bentonite pellets. The foundation layer consists of Milos bentonite granules, which are compacted in situ in order to level the deposition tunnel floor, providing an even and stable base for the block filling. On the foundation layer, a rigid assemblage of overlapping layers of pre-compacted blocks made of Friedland clay are installed. The void space between the blocks and the rock wall is filled with extruded pellets made of bentonite similar to raw material of Cebogel QSE product.

    Avainsanat - Keywords

    Backfill, bentonite, block, design, foundation layer, Friedland clay, KBS-3V, pellet.

    ISBN ISBN 978-951-652-196-4

    ISSN ISSN 1239-3096

    Sivumäärä – Number of pages 80

    Kieli – Language English

    Posiva-raportti – Posiva Report Posiva Oy Olkiluoto FI-27160 EURAJOKI, FINLAND Puh. 02-8372 (31) – Int. Tel. +358 2 8372 (31)

    Raportin tunnus – Report code

    POSIVA 2012-15 Julkaisuaika – Date

    December 2013

  • Tekijä(t) – Author(s) Jorma Autio, Md. Mamunul Hassan, Petriikka Karttunen, Paula Keto, B+Tech Oy

    Toimeksiantaja(t) – Commissioned by

    Posiva Oy

    Nimeke – Title

    LOPPUSIJOITUSTUNNELIEN TÄYTÖN SUUNNITELMA 2012

    Tiivistelmä – Abstract

    Tämä työ sisältää KBS-3V-loppusijoitustunnelin täytön käsitteellisen ja yksityiskohtaisen suunnitelman. Täytön tarkoituksena on pitää puskuri paikallaan sekä ylläpitää suotuisia ja ennus- tettavissa olevia olosuhteita puskurille ja kapselille. Lisäksi täytön tarkoituksena on ylläpitää suotuisia kalliomekaanisia, hydrologisia ja geokemiallisia olosuhteita loppusijoitusreiän lähi- alueella sekä rajoittaa kanisterivikatapauksessa vapautuvien radionuklidien kulkeutumista. Yleisellä tasolla olevan täyttösuunnitelman lisäksi kaikille täyttökomponenteille (lattia-, lohko- ja pellettitäyttö) on tässä raportissa esitetty yksityiskohtaiset suunnitelmat. Loppusijoitustunnelin päätytulpan suunnitelmaa ei ole esitetty tässä dokumentissa. Loppusijoitustunneli on suunniteltu täytettäväksi lattiatäyttömateriaalilla, esipuristetuilla savi- lohkoilla sekä pelletöidyllä bentoniitilla. Lattiatäyttömateriaali koostuu alkuperältään Milokselta olevasta granuli-muotoisesta bentoniitista. Materiaali tiivistetään ja sen avulla muodostetaan tasainen ja kantava pohja lohkotäytölle. Lattiatäytön päälle asennetaan limittäin ja kerroksittain esipuristettuja Friedland-savesta valmistettuja lohkoja, jotka muodostavat tiiviin pinon. Tunneli- seinämän ja lohkopinon välinen rako täytetään pelletöidyllä bentoniitilla, joka on valmistettu Cebogel QSE -pellettien raaka-aineen kaltaisesta materiaalista.

    Avainsanat - Keywords

    Bentoniitti, Friedland-savi, KBS-3V, lattiatäyttö, lohko, pelletti, suunnitelma, täyttö.

    ISBN ISBN 978-951-652-196-4

    ISSN ISSN 1239-3096

    Sivumäärä – Number of pages 80

    Kieli – Language Englanti

    Posiva-raportti – Posiva Report Posiva Oy Olkiluoto FI-27160 EURAJOKI, FINLAND Puh. 02-8372 (31) – Int. Tel. +358 2 8372 (31)

    Raportin tunnus – Report code

    POSIVA 2012-15 Julkaisuaika – Date

    Joulukuu 2013

  • FOREWORD The backfill design presented in this report is based on design work started by Jorma Autio (B+Tech Oy) in 2011. Md. Mamunul Hassan (B+Tech Oy) provided detailed descriptions of block filling designs, and all the design work connected with this topic was carried out by him. Paula Keto (B+Tech Oy) edited the report in 2012 to be in accordance with the Backfill Production Line report and wrote sections concerning design requirements. Petriikka Karttunen and Leena Kiviranta (B+Tech Oy) contributed to the content of the report and handled review comments together with Paula Keto. Xavier Pintado and Jorma Autio from B+Tech Oy reviewed the report as B+Tech’s internal reviewers. Petri Koho and Petri Korkeakoski from Posiva Oy acted as the client’s representatives and provided review comments. Timo Kirkkomäki (Fortum Oyj) provided information presented in Appendix 1, Olli Salo from Saanio & Riekkola Oy wrote Appendix 2 and Leena Kiviranta and Petriikka Karttunen from B+Tech Oy wrote Appendix 3. Rick McArthur corrected the language. The official review of the report was done by Markku Juvankoski (VTT), Heini Laine (Saanio & Riekkola Oy) Petri Korkeakoski and Jukka-Pekka Salo from Posiva Oy. In addition, unofficial review comments were provided by David Dixon (AECL) and Aimo Hautojärvi (Posiva Oy). Thanks are due to all the experts mentioned above for contributing their design expertise, and for their help in writing this report.

  • ABBREVIATIONS AND DEFINITIONS Arch/arch zone The uppermost part of the deposition tunnel, the arched

    tunnel roof.

    Backfill Backfill is the material or materials used to fill deposition tunnels.

    Block filling The backfill component which occupies the largest volume of the deposition tunnel. Consists of pre-compacted blocks.

    Block filling degree Block filling degree is defined as the ratio of the volume of blocks divided by the theoretical (i.e. nominal) volume of the tunnel. If block filling degree is defined from the realised tunnel volume, this is noted separately in the sentence.

    Block layout An arrangement which allows the largest volume of a deposition tunnel to be filled with pre-compacted blocks. There are two block layouts: one for the Loviisa deposition tunnels and one for Olkiluoto deposition tunnels.

    Block orientation system There are two different block orientation systems (A and B). In each system every block is in same direction. When an A layer is installed on top of a B layer, the blocks overlap and vertical gaps do not span more than a single block layer.

    Buffer Compacted bentonite blocks and pellets surrounding the copper canister in the deposition hole.

    Bulk density Bulk density is the ratio of the total mass of dry solids and water to the bulk volume and calculated as ρb = (ms+mw/Vs (kg/m3).

    Cebo Holland BV Supplier of bentonite raw material.

    Cebogel QSE Cylindrical, compacted bentonite rod product manufactured by Cebo Holland BV consisting of 100% activated sodium bentonite.

    Central tunnel A tunnel which provides access to deposition tunnels. A repository always has two parallel central tunnels. The cross-sectional area of a central tunnel is larger than the cross-sectional area of a deposition tunnel.

    Chamfer A bevel in the uppermost part of a deposition hole which makes installation of the canister easier.

    Conceptual design Backfilling design at a general level.

  • Degree of water saturation, Sr (%) The degree of water saturation is the ratio between the

    volume of the pore water and the pore volume.

    P

    w r V

    V xS 100

    Deposition hole The vertical hole where the disposal canister and the surrounding buffer are emplaced in the KBS-3V concept.

    Deposition tunnel The tunnel, where deposition holes are located in the KBS- 3V concept.

    Deposition tunnel plug A plug made of low pH concrete and filter and sealing materials. The plug is installed in the mouth of a deposition tunnel after the backfill has been installed.

    Design basis Performance targets and target properties for the repository system.

    Design boundary A boundary which separates design entities. Examples include the boundary between the backfill and buffer designs, and the boundary between the backfill and the plug designs.

    Design requirement Design requirements are ultimately defined so as to enable the achievement of the performance targets in the expected scenarios.

    Design specification Design specifications are firm, quantitative specifications for the design based on the pe