Expansion of flashing fuel simulants into the upper core structures using CRBR and SNR geometries

In collaboration with KfK Karlsruhe, an experimental program is being executed at Los Alamos to examine the validity of models and parameters used in SIMMER-II for the expansion phase of a hypothetical core-disruptive accident. Subject of the work is the expansion of a flashing fuel simulant into the Upper Core Structures of an LMFBR. These structures consist of scaled down subassemblies in CRBR and SNR geometries. During the expansion in this UPPER STRUCTURE DYNAMICS experiment, pressures, temperatures and an equivalent of the sodium pool displacement are monitored and compared with SIMMER-II analyses