The PHEBUS fission products programme

A. Mailliat
EUROCOURSE 2003 CORIUM : Severe Accident R&D and Nuclear Power Plant Safety Janvier 27-31, 2003, Aix en Provence.

The main issues for reactor safety in case of severe accident sequences are the containment integrity and the characteristics of the Source Term. Since the TMI2 accident, in March 79, the progress of research has made it possible to estimate the potential consequences of a rather large spectrum of severe accidents sequences. The Phebus-FP programme is a wide international effort to investigate LWR severe accident phenomena, through a series of in-pile integral experiments, dealing with fuel degradation, hydrogen production, fission product release and subsequent transport/deposition in the Reactor Coolant System down to the containment building. Three tests (FPT0, 1, 2) have so far been successfully performed, which provide experimental data of high interest to characterise and improve LWR safety in the event of a severe accident. The data analysis of FPT0 and FPT1 is now terminated (and available in the open literature for FPT0), while that of FPT2 is still under progress. The present paper gives a brief overview of the lessons learnt so far regarding the core degradation and corium behaviour in these three tests.