Re-Evaluation of SEFOR Doppler Experiments and Analysis with JNC and ERANOS systems

Hazama, Taira ; Tommasi, J.*

SEFOR (South-West Experimental Fast Oxide Reactor) Doppler reactivity experiment was re-evaluated. The re-evaluation was carried out on the static tests performed at power levels up to 20MW, starting from raw data of the Doppler reactivity and fuel temperature. Investigations are made on various parameters, such as the fuel thermal conductivity and weighting function to obtain core averaged fuel temperature. Experimental uncertainty is also re-evaluated. The re-evaluated Doppler constant is about 10% larger than the original GE evaluation. The increase is brought by the use of the exact weight to consider temperature distribution in the core and the update of fuel thermal conductivity. The new values are more reasonable than the currently recommended values in that C/E values do not depend on the core types.