Water chemistry and oxidation in the primary circuit (WATCHEM): WATCHEM summary report: Development and verification of in situ techniques to study oxidation and water chemistry effects in the primary circuit

    Research output: Chapter in Book/Report/Conference proceedingChapter or book articleProfessional

    Abstract

    The focus in the WATCHEM project has been in development of in situ methods (a) to study oxidation of fuel cladding alloys and (b) to study optimisation of passivation (i.e. Hot Conditioning) of PWR reactor circuit surfaces prior to first fuel loading. The Controlled Distance Electrochemistry (CDE) method has been shown to be reliable and to give consistent and repeatable results both in BWR and in PWR conditions. Comparisons of the effects of elevated Li+ (PWR) and K+ (WWER) concentrations on fuel cladding oxidation were performed as part of this project. In studying the sensitivity limits of the CDE method the effects of F- concentration in the beginning of cycle conditions of WWER on Zr-1Nb alloy oxidation were found to be negligible at levels below 100 ppb. Based on a literature study the optimal water chemistry conditions in PWRs for Inconel 600 and 690 materials are 0.5-1 ppm Li+ and 25-30 ccH2/kgH2O. There is a considerable uncertainty in determining the effect of boric acid and the minimum required hot conditioning time. Two new methods were developed in co-operation with Bhabha Atomic Research Centre (BARC), India, to study the optimisation of the hot conditioning procedure and verified for carbon steel under PHWR water chemistry conditions. Preliminary studies with Inconel 690 under PWR conditions are underway.
    Original languageEnglish
    Title of host publicationSAFIR2010: The Finnish Research Programme on Nuclear Power Plant Safety 2007-2010
    Subtitle of host publicationInterim Report
    Place of PublicationEspoo
    PublisherVTT Technical Research Centre of Finland
    Pages354-362
    ISBN (Electronic)978-951-38-7267-0
    ISBN (Print)978-951-38-7266-3
    Publication statusPublished - 2009
    MoE publication typeNot Eligible

    Publication series

    SeriesVTT Tiedotteita - Research Notes
    Number2466
    ISSN1235-0605

    Fingerprint Dive into the research topics of 'Water chemistry and oxidation in the primary circuit (WATCHEM): WATCHEM summary report: Development and verification of in situ techniques to study oxidation and water chemistry effects in the primary circuit'. Together they form a unique fingerprint.

  • Cite this

    Saario, T., & Kinnunen, P. (2009). Water chemistry and oxidation in the primary circuit (WATCHEM): WATCHEM summary report: Development and verification of in situ techniques to study oxidation and water chemistry effects in the primary circuit. In SAFIR2010: The Finnish Research Programme on Nuclear Power Plant Safety 2007-2010 : Interim Report (pp. 354-362). VTT Technical Research Centre of Finland. VTT Tiedotteita - Research Notes, No. 2466 http://www.vtt.fi/inf/pdf/tiedotteet/2009/T2466.pdf