Progress report of research on supercritical pressure light water reactor

Supercritical pressure light water reactor is the concept of the once-through type reactor using supercritical pressure water as the coolant. By adopting once-through type for reactor system, the system can be simplified drastically. As the coolant at core exit is high temperature and high pressure, the thermal efficiency heightens. Accordingly, the reduction of construction cost can be expected. By making the fuel grid dense and arranging blankets, it can be made into fast breeder reactor. The core design for a thermal neutron reactor (SCLWR) taking radial power distribution in consideration is explained. The materialization of the steam cycle for the SCLWR was investigated, and the thermal efficiency was accurately evaluated. By the assumed steam cycle, the thermal efficiency of 41.3% was obtained. The research on the plant control of a SCFBR was carried out by the analysis of the dynamic characteristics peculiar to the plant without control system, and the analysis by adding control system again. The code for analyzing the transient change of a SCLWR and a SCFBR plants was made, and the analysis of transient change and accidents regarding supposed flow rate, pressure and control rod was carried out. The results are reported. (K.I.)