NUCLEAR REACTOR PRESSURE VESSEL AND NUCLEAR REACTOR PRESSURE VESSEL COOLING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a nuclear reactor pressure vessel capable of appropriately cooling a bottom of a vessel main body at a time of a severe accident while ensuring heat insulation performance during normal operation.SOLUTION: According to an embodiment, a vessel main body 12 of a nuclear reactor vessel 10 contains therein a reactor core and includes a bottom 16 just under the reactor core. The nuclear reactor vessel 10 includes: an outer wall 20 provided outside of the vessel main body 12 at a distance from the vessel main body 12, an internal space 22 being formed between the bottom 16 and the outer wall 20; and jet nozzles 30 jetting water toward the bottom 16 from outside of the bottom 16 at a time of a severe accident. A steam exhaust port 26 discharging steam from the internal space 22 at the time of the severe accident is formed in the outer wall 20. The nuclear reactor pressure vessel 10 further includes a closing member closing the steam exhaust port 26 during normal operation.