| 摘要 |
PROBLEM TO BE SOLVED: To eliminate the possibility of critical failure including a missing of coolant, substantially, by providing a pipe penetrating the wall of a pressure vessel with an isolation valve for choking the flow of fluid selectively. SOLUTION: A concrete nuclear reactor(PCRV) 2 comprises a pressure vessel section 2a and a containing section 2b having an inner surface applied with a steel liner 4. A dome 6 at the top of pressure vessel section 2a has a flange being tightened by means of a tension nut 8 at the end of a vertical tension member 10a buried in concrete. A pipe penetrating the wall of PCRV 2 is provided with an isolation valve 26a disposed in a vertical valve tunnel 42 enclosed by a cover plate 44. The tunnel 42 controls leakage and provides an access for maintenance. Pressure in the tunnel 42 is monitored by means of a pressure sensor 40 in order to detect leakage. When a leakage is detected, the nuclear reactor is isolated (isolation valves 26a-26d are closed to keep the water level) and the operation is interrupted for repair.
|
