Innovations on life management of VVER reactor pressure vessels

Antero Tamminen, Jyrki Kohopää, Matti Valo, Jussi Solin

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

    Abstract

    The embrittlement rate of the pressure vessel weld material is a dominating factor in life management of VVER reactor pressure vessels. In order to maintain adequate safety level, several backfitting measures have been performed in Loviisa. The neutron flux and embrittlement rate was reduced after receiving the first indications of anticipated problems. An increase of emergency core cooling water temperature and other process related changes followed to eliminate and reduce potential transients. Finally, the core weld of Loviisa 1 was successfully annealed in 1996. A current concern is to verify the post-annealing embrittlement rate in order to enable safe and economic life management of the RPV. Post-annealing re-embrittlement is governed by somewhat different mechanisms than the embrittlement of the first irradiation cycle. A new tentative approach for predicting the re-embrittlement rate has been proposed.
    Original languageEnglish
    Title of host publicationBALTICA V
    Subtitle of host publicationCondition and Life Management for Power Plants
    Place of PublicationEspoo
    PublisherVTT Technical Research Centre of Finland
    Pages665-680
    Volume2
    ISBN (Electronic)951-38-5717-4
    ISBN (Print)951-38-5716-6
    Publication statusPublished - 2001
    MoE publication typeA4 Article in a conference publication
    EventBALTICA V - Condition and Life Management for Power Plants - Porvoo, Finland
    Duration: 6 Jun 20018 Jun 2001

    Publication series

    SeriesVTT Symposium
    Number212
    ISSN0357-9387

    Conference

    ConferenceBALTICA V - Condition and Life Management for Power Plants
    Abbreviated titleBaltica V
    CountryFinland
    CityPorvoo
    Period6/06/018/06/01

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    Keywords

    • innovation

    Cite this

    Tamminen, A., Kohopää, J., Valo, M., & Solin, J. (2001). Innovations on life management of VVER reactor pressure vessels. In BALTICA V: Condition and Life Management for Power Plants (Vol. 2, pp. 665-680). VTT Technical Research Centre of Finland. VTT Symposium, No. 212