Water experiment and numerical simulation on failed fuel detection and location system of japan sodium-cooled fast reactor (JSFR)

作者：Aizawa Kosuke^*; Ohshima Jun; Kamide Hideki; Kasahara Naoto

来源：Journal of Nuclear Science and Technology, 2012, 49(1-2): 47-60.

DOI：10.1080/18811248.2011.636539

• sodium-cooled fast reactor
• selector-valve type FFDL system
• UIS
• sampling nozzles
• fission product

A conceptual design study of Japan sodium-cooled fast reactor (JSFR) is in progress as the "Fast Reactor Cycle Technology Development (FaCT)" project in Japan. A selector-valve type failed fuel detection and location (FFDL) system is applied to the JSFR design that has an upper internal structure (UIS) with a slit above the core and several sampling nozzles for the FFDL are set in the UIS around the slit to detect the fission product (FP) from the subassemblies below the slit. Therefore, mixing process in the UIS of complicated geometry should be known and appropriate arrangement of the sampling nozzles in the UIS is needed. A water experiment using a 1/5-scale model was carried out to investigate the mixing process in the UIS and concentration distribution of FP simulant. Experimental results showed that the sampling nozzles set in the UIS detected the FP simulant concentration within the criteria of FFDL signal detection, even in case of failed subassemblies under the UIS slit. In addition, identification of the failed fuel subassembly under the UIS slit was achieved by means of comparing concentration profiles in the UIS. Therefore, the suitable sampling nozzle arrangement was obtained for JSFR. A numerical simulation using a CFD code was carried out and the simulation method was validated based on the experimental data of the FP simulant concentrations. The simulation results showed that the simulation predicts the FP concentration distributions.

• 出版日期2012-2