Benchmark analysis of FFTF Loss of Flow Without Scram Test No.13 using fast reactor plant dynamics analysis code Super-COPD

Hamase, Erina ; Ohgama, Kazuya   ; Kawamura, Takumi*; Doda, Norihiro  ; Yamano, Hidemasa   ; Tanaka, Masaaki  

To improve the prediction accuracy of the plant dynamics analysis code named Super-COPD, JAEA has joined the IAEA benchmark for the FFTF Loss of Flow Without Scram Test No.13. In the first blind phase, there was the challenge to perform outlet temperatures of fuel assemblies more accurately. Hence, the renewed analysis was performed with the whole core multi-channel model in which each assembly was modelled to simulate the radial heat transfer among assemblies and the flow redistribution induced by the buoyancy in the NC conditions. Then, to validate the coupled transient analysis between the whole core multi-channel model and the one-point kinetics model, the analysis considering major reactivity feedbacks such as GEM, assembly bowing was performed. As a result, the second peak of outlet temperatures was reproduced successfully, and it was observed that the plant dynamics analysis could follow the measured data.