Description and preliminary results of PHENIX core flowering test

In order to study the core compaction of an authentic sodium-cooled fast reactor and the neutronic consequences of its modification, core flowering tests were performed in the PHENIX reactor within the context its 2009 end-of-life tests. A dedicated in-pile device was designed and manufactured to actuate fuel assemblies and generate mechanical core flowering. During the test, which was performed under different temperature conditions, assembly displacements, flowering forces and reactivity signals were recorded. The mechanical analysis of these results indicates that core compaction seems to be dependent on temperature. The evolution of reactivity with flowering remains negative, even if the flowering source is located in external core.

► Core flowering tests performed in PHENIX reactor. ► A dedicated in-pile device was designed and manufactured to actuate on fuel assemblies and generate a mechanical core flowering. ► Core compaction seems to be dependant of temperature. ► The evolution of reactivity with flowering remains negative, even if the flowering source is located in external core.