Revisited analysis of the PUIREX 2008 decay heat experiment in the Phénix Sodium Fast Reactor

Fast neutron reactors are of particular interest in the context of reducing carbon emissions, as they offer an attractive uranium economy and are crucial for closing the fuel cycle. To construct new reactors, safety issues must be studied thoroughly, and decay heat is a critical parameter, as demonstrated during the Fukushima accident. To ensure reactor safety, it is necessary to know the decay heat throughout the fuel cycle. Calculation tools are being developed at CEA and have been validated by comparing them with experiments performed in Sodium Fast Reactors Phénix and Superphénix. For many years, there have been inconsistencies between the experimental and calculated decay heat values for French SFRs. The analysis of the 2008 PUIREX experiment in Phénix has been revisited, and a new method has been tested to obtain the decay heat from temperature measurements. Explanations for the discrepancies with the calculations have been found.