Transport of ruthenium in primary circuit conditions during a severe NPP accident

Teemu Kärkelä (Corresponding Author), N Ver, T Haste, N Davidovich, Jouni Pyykönen, L Cantrel

    Research output: Contribution to journalArticleScientificpeer-review

    Abstract

    Ruthenium species, volatilized from damaged fuel during a severe accident in a nuclear power plant, are radiotoxic and can be transported to the containment atmosphere in gaseous form. To limit the possible source term to the environment, it is of interest to understand the behaviour of Ru after it has been released from fuel and the phenomena taking place within the decreasing temperature section of the reactor coolant system. This was investigated in the framework of EC SARNET and EC SARNET2 programs, as a part of the Source Term work package, with several separate-effect tests on the transport and speciation of Ru in primary circuit conditions considering the influence of other fission products as well. The source of Ru was metallic Ru, RuO2 powder or gaseous RuO4. The large-scale integral tests of the Phébus FP program were conducted with real irradiated fuel, and more realistic analysis on the release and transport of Ru could be performed. Experimental studies proved that the transport of ruthenium to the containment atmosphere took mainly place as RuO2 particles when Ru source was oxidized above 1250°C. The fraction of Ru transported in gaseous form was at its highest when ruthenium was oxidized at approx. 1000 °C to 1100 °C. A major part of the released Ru was deposited at the decreasing temperature area of the circuit as RuO2. Revaporisation of the deposited Ru at low temperature was a significant source of gaseous ruthenium. In order to understand the behaviour of ruthenium in these tests, the analysis work was extensive and several simulations were carried out. As an outcome, the observed transport and deposition of ruthenium was explained. The simulation studies gave also an insight into the performance of the ASTEC code and some model improvements for Ru transport through the RCS have been identified
    Original languageEnglish
    Pages (from-to)173-183
    JournalAnnals of Nuclear Energy
    Volume74
    DOIs
    Publication statusPublished - 2014
    MoE publication typeNot Eligible
    Event6th European Review meeting on Severe Accident Research, ERMSAR-2013 - Avignon, France
    Duration: 2 Oct 20134 Oct 2013
    Conference number: 6

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    Ruthenium
    Accidents
    Networks (circuits)
    Fission products
    Coolants
    Temperature
    Nuclear power plants
    Powders

    Cite this

    Kärkelä, Teemu ; Ver, N ; Haste, T ; Davidovich, N ; Pyykönen, Jouni ; Cantrel, L. / Transport of ruthenium in primary circuit conditions during a severe NPP accident. In: Annals of Nuclear Energy. 2014 ; Vol. 74. pp. 173-183.
    @article{9c0035aeaebf4d4b9497848e164d9ceb,
    title = "Transport of ruthenium in primary circuit conditions during a severe NPP accident",
    abstract = "Ruthenium species, volatilized from damaged fuel during a severe accident in a nuclear power plant, are radiotoxic and can be transported to the containment atmosphere in gaseous form. To limit the possible source term to the environment, it is of interest to understand the behaviour of Ru after it has been released from fuel and the phenomena taking place within the decreasing temperature section of the reactor coolant system. This was investigated in the framework of EC SARNET and EC SARNET2 programs, as a part of the Source Term work package, with several separate-effect tests on the transport and speciation of Ru in primary circuit conditions considering the influence of other fission products as well. The source of Ru was metallic Ru, RuO2 powder or gaseous RuO4. The large-scale integral tests of the Ph{\'e}bus FP program were conducted with real irradiated fuel, and more realistic analysis on the release and transport of Ru could be performed. Experimental studies proved that the transport of ruthenium to the containment atmosphere took mainly place as RuO2 particles when Ru source was oxidized above 1250°C. The fraction of Ru transported in gaseous form was at its highest when ruthenium was oxidized at approx. 1000 °C to 1100 °C. A major part of the released Ru was deposited at the decreasing temperature area of the circuit as RuO2. Revaporisation of the deposited Ru at low temperature was a significant source of gaseous ruthenium. In order to understand the behaviour of ruthenium in these tests, the analysis work was extensive and several simulations were carried out. As an outcome, the observed transport and deposition of ruthenium was explained. The simulation studies gave also an insight into the performance of the ASTEC code and some model improvements for Ru transport through the RCS have been identified",
    author = "Teemu K{\"a}rkel{\"a} and N Ver and T Haste and N Davidovich and Jouni Pyyk{\"o}nen and L Cantrel",
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    Transport of ruthenium in primary circuit conditions during a severe NPP accident. / Kärkelä, Teemu (Corresponding Author); Ver, N; Haste, T; Davidovich, N; Pyykönen, Jouni; Cantrel, L.

    In: Annals of Nuclear Energy, Vol. 74, 2014, p. 173-183.

    Research output: Contribution to journalArticleScientificpeer-review

    TY - JOUR

    T1 - Transport of ruthenium in primary circuit conditions during a severe NPP accident

    AU - Kärkelä, Teemu

    AU - Ver, N

    AU - Haste, T

    AU - Davidovich, N

    AU - Pyykönen, Jouni

    AU - Cantrel, L

    N1 - Project code: TRAFI 77652

    PY - 2014

    Y1 - 2014

    N2 - Ruthenium species, volatilized from damaged fuel during a severe accident in a nuclear power plant, are radiotoxic and can be transported to the containment atmosphere in gaseous form. To limit the possible source term to the environment, it is of interest to understand the behaviour of Ru after it has been released from fuel and the phenomena taking place within the decreasing temperature section of the reactor coolant system. This was investigated in the framework of EC SARNET and EC SARNET2 programs, as a part of the Source Term work package, with several separate-effect tests on the transport and speciation of Ru in primary circuit conditions considering the influence of other fission products as well. The source of Ru was metallic Ru, RuO2 powder or gaseous RuO4. The large-scale integral tests of the Phébus FP program were conducted with real irradiated fuel, and more realistic analysis on the release and transport of Ru could be performed. Experimental studies proved that the transport of ruthenium to the containment atmosphere took mainly place as RuO2 particles when Ru source was oxidized above 1250°C. The fraction of Ru transported in gaseous form was at its highest when ruthenium was oxidized at approx. 1000 °C to 1100 °C. A major part of the released Ru was deposited at the decreasing temperature area of the circuit as RuO2. Revaporisation of the deposited Ru at low temperature was a significant source of gaseous ruthenium. In order to understand the behaviour of ruthenium in these tests, the analysis work was extensive and several simulations were carried out. As an outcome, the observed transport and deposition of ruthenium was explained. The simulation studies gave also an insight into the performance of the ASTEC code and some model improvements for Ru transport through the RCS have been identified

    AB - Ruthenium species, volatilized from damaged fuel during a severe accident in a nuclear power plant, are radiotoxic and can be transported to the containment atmosphere in gaseous form. To limit the possible source term to the environment, it is of interest to understand the behaviour of Ru after it has been released from fuel and the phenomena taking place within the decreasing temperature section of the reactor coolant system. This was investigated in the framework of EC SARNET and EC SARNET2 programs, as a part of the Source Term work package, with several separate-effect tests on the transport and speciation of Ru in primary circuit conditions considering the influence of other fission products as well. The source of Ru was metallic Ru, RuO2 powder or gaseous RuO4. The large-scale integral tests of the Phébus FP program were conducted with real irradiated fuel, and more realistic analysis on the release and transport of Ru could be performed. Experimental studies proved that the transport of ruthenium to the containment atmosphere took mainly place as RuO2 particles when Ru source was oxidized above 1250°C. The fraction of Ru transported in gaseous form was at its highest when ruthenium was oxidized at approx. 1000 °C to 1100 °C. A major part of the released Ru was deposited at the decreasing temperature area of the circuit as RuO2. Revaporisation of the deposited Ru at low temperature was a significant source of gaseous ruthenium. In order to understand the behaviour of ruthenium in these tests, the analysis work was extensive and several simulations were carried out. As an outcome, the observed transport and deposition of ruthenium was explained. The simulation studies gave also an insight into the performance of the ASTEC code and some model improvements for Ru transport through the RCS have been identified

    U2 - 10.1016/j.anucene.2014.07.010

    DO - 10.1016/j.anucene.2014.07.010

    M3 - Article

    VL - 74

    SP - 173

    EP - 183

    JO - Annals of Nuclear Energy

    JF - Annals of Nuclear Energy

    SN - 0306-4549

    ER -