| 摘要 |
<P>PROBLEM TO BE SOLVED: To realize means which suppresses the increase of pressure in a nuclear reactor containment vessel due to a severe accident, while preventing discharge of radioactive substances to the environment and reaction between a combustible gas and oxygen and taking economic efficiency into consideration, and to reduce a risk to a worker who enters an upper reactor building during normal operation. <P>SOLUTION: A reactor building comprises a nuclear reactor containment vessel 3 and an upper reactor building 9 which is located above an ancillary building surrounding a region of the nuclear reactor containment vessel 3. An airtight space 13 is provided in an upper section of the upper reactor building 9. A wetwell 5 and the airtight space 13 are connected by a discharge conduit 14 via a rupture disk 11 which is released when a pressure in the wetwell 5 increases to approach a limit value. The airtight space 13 is connected to a vacuum pump of a vacuum exhaust system via an isolation valve 16. An operation of the vacuum exhaust system and an opening operation of the isolation valve 16 are triggered by generation of a severe accident occurrence signal, and the vacuum pump is stopped to close the isolation valve 16 before the pressure in the wetwell 5 reaches a pressure at which the rupture disk 11 is released. <P>COPYRIGHT: (C)2012,JPO&INPIT |
