Non-destructive evaluation of the spent nuclear fuel disposal canisters

Ari Koskinen, Tarja Jäppinen

    Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

    Abstract

    The Finnish concept of high activity nuclear waste disposal is based on deep geological storage in copper canisters with cast iron inserts. The development of disposal concept and final disposal in Finland is managed and organised by Posiva Oy. Disposal canisters will be embedded in Olkiluoto bedrock at a depth of approximately 400 metres. Therefore it is essential to inspect the canisters with non-destructive testing (NDT) methods as well as possible before the final disposal. The lid of the copper disposal canister for high activity nuclear waste is sealed with a weld. Before accepting the canister to the final disposal the weld is planned to be inspected by four non-destructive testing methods. These methods are ultrasonic testing (UT), radiographic testing (RT), eddy current testing (ET) and remote visual testing (VT) using cameras. The copper overpack and the lid are also inspected with multiple NDT methods; UT, ET and VT. The nodular cast iron insert is inspected with UT and VT. In this paper the four NDT inspection methods (UT, RT, ET, VT) for inspection of different parts of the disposal canister are presented in brief. All information in this paper is collected and summarised from public reports and from the procedures of each method and inspection records. All of the four NDT methods detect defects in slightly different directions and based on different physical principles. The four methods are therefore supplements to each other in inspection of different parts of the disposal canister.
    Original languageEnglish
    Title of host publicationBaltica X
    Subtitle of host publicationInternational Conference on Life Management and Maintenance for Power Plants
    EditorsPertti Auerkari
    Place of PublicationEspoo
    PublisherVTT Technical Research Centre of Finland
    Number of pages10
    ISBN (Electronic)978-951-38-8436-9, 978-951-38-8435-2
    Publication statusPublished - 2016
    MoE publication typeA4 Article in a conference publication
    EventBALTICA X - International Conference on Life Management and Maintenance for Power Plants - Cruise, Helsinki-Stockholm, Finland
    Duration: 7 Jun 20169 Jun 2016

    Publication series

    SeriesVTT Technology
    Volume261

    Conference

    ConferenceBALTICA X - International Conference on Life Management and Maintenance for Power Plants
    Abbreviated titleBaltica X
    CountryFinland
    CityHelsinki-Stockholm
    Period7/06/169/06/16

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    Cite this

    Koskinen, A., & Jäppinen, T. (2016). Non-destructive evaluation of the spent nuclear fuel disposal canisters. In P. Auerkari (Ed.), Baltica X: International Conference on Life Management and Maintenance for Power Plants VTT Technical Research Centre of Finland. VTT Technology, Vol.. 261