Use of model materials for fission products release study in Severe Accident Conditions

E. Geiger (1) , R. Bes (1) , Yves Pontillon (1) , P. Martin (1) , G. Ducros (1)

1 CEA-DES (ex-DEN) - CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire)

Many integral and analytical research programs, such as PHEBUS FP, HI/VI, VEGA, VERCORS, etc., have been carried out aiming to understand the behaviour of fission products during a Nuclear Severe Accident. Most of them used standard PWR or BWR nuclear fuels with burn-ups going from traces up to about 70-80 GWd/t, which implied sophisticated experiments. Another way to study these matters is to use Model Materials doped with stable Fission Products in concentrations representative of a given burn-up, known as SIMFUEL. In order to demonstrate that they are an efficient alternative to irradiated fuel in the SA study, SIMFUEL samples doped with up to 12 Fission Products were submitted to annealing treatments in conditions representative of severe accidents. Samples were characterised before and after the tests by SEM-EDX and XAS, at SOLEIL and ESRF Synchrotrons, which are yet unavailable for irradiated fuels. Despite the limitations of SIMFUELS, it was found that the overall behaviour of fission products was similar to that observed for irradiated fuels and also consistent with thermodynamic estimations the common chemical phases other than the fuel matrix were reproduced as well as the general fission products behaviour, in terms of release from the sample.

Keywords: model materials; severe accidents; fission products behaviour

Domains: Nuclear Experiment [nucl-ex]; Nuclear Theory [nucl-th]

E. Geiger, R. Bes, Yves Pontillon, P. Martin, G. Ducros. Use of model materials for fission products release study in Severe Accident Conditions. ERMSAR 2015 - 7th European Review Meeting on Severe Accident Research, Mar 2015, Marseille, France. ⟨cea-02509278⟩