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.
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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

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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 -