Development of fast reactor fuel design code; Improvement of stress-strain analysis model and code verifications

Shiramizu, Miho; Ozawa, Takayuki

no journal, , 

The reasonable design margin would be required to improve the performances in FBR. For this, the fuel pellet deformation should be precisely computed to predict the PCMI behavior and the annular deformation. Although a fuel pellet is radially divided into several rings for thermal computation, but for stress-strain computation assumed to be only a cylinder in the fuel design code. In this study, we improved the code to make the stress-strain analysis in a fuel pellet also, and verified the computations. In thermal verifications, the data of fuel temperature and fuel restructuring obtained from the instrumented test assembly (INTA) tests and the power-to-melt (PTM) tests were compared with computations, and in mechanical verifications, the data for annular fuel pellet and cladding deformation obtained from irradiation tests in PFR were compared. As a result of verifications, the improved code could precisely predict not only temperature but also deformation of fuel pellet and cladding.