Summary Report for U.S. and Japan Bilateral Collaborations (FY2019)

Abstract

Within the frame work of the Civil Nuclear Energy R&D Working Group (CNWG), researchers from Argonne National Laboratory (ANL), Japan Atomic Energy Agency (JAEA) and Central Research Institute of Electric Power Industry (CRIEPI) have been participating in the R&D collaborations in three tasks that are related to the fast reactor technologies, which include metal fuel sodium-cooled fast reactor (SFR) core bowing analysis, modeling and simulation of Monju Turbine Trip Benchmark, and collaborative improvement of the SAS4A code. The core bowing analysis continued for two benchmark problems: IAEA bowing benchmark problem and ABR-1000 bowing problem. A correction was made to the IAEA VP4 bowing benchmark problem by adding in the clearance at the restraint rings, and the results were updated. The ABR-1000 bowing problem parameters were updated in this work to include analysis of the full core. Two accident cases, were introduced to investigate the response due to a single control-rod removal accident scenario. The input files were created and provided to Japanese collaborators. A NUBOW3D model was created for the ABR-1000 and preliminary results were obtained for all load cases for the ABR-1000 bowing benchmark problem. Finally, a new irradiation benchmark problem was introduced that included a single duct (CNWG-1A) to investigate irradiation swelling effects, and a two-duct contact problem (CNWG-1B) to investigate creep effects.

Core thermal-hydraulics analysis during dipped-type direct heat exchanger operation in natural circulation conditions

“…Tables and 3 show the numerical options to solve NC conditions in PLANDTL-1 and simulation case conditions, respectively. The Realizable k-ε model was applied in the whole analysis domain except the bundle region of the subassembly and the interwrapper gap to consider the turbulence viscosity and thermal diffusion because it was reported its applicability for the thermal stratification in the plenum and pipe by the exiting studies (Farkas and Tóth, 2010;Bieder et al, 2017;Grudzinski et al, 2019). As mentioned above the section 3.2 and 3.3, the laminar option was selected in the bundle region of the subassembly, where the correlations taking into account of the effect of turbulence viscosity and thermal diffusion were employed, and the interwrapper gap.…”