Patent Number: 051981840
Section: abstract

A reactor pressure vessel is disposed in a reactor containment vessel and is supported by a pedestal having a cylindrical structure. The inside of the reactor containment vessel is divided into upper and lower drywells by means of a diaphragm floor. A line, a cable and a duct are disposed in and between the upper and lower drywells in the reactor containment vessel. The pedestal comprising a plurality of concrete wall sections and a plurality of connecting vent sections which are arranged alternately along a circumferential direction of the cylindrical pedestal, wherein the line, the cable and the duct are arranged in each of the connecting vent sections and a vent pipe is arranged in each of the concrete sections. A vacuum breaker is further disposed in the reactor containment vessel at a portion above the open end of the vent pipe, the vacuum breaker is connected to a fixing pipe for mounting a vacuum breaker to the pedestal and the fixing pipe has one end opened to the drywell. The vent pipe may have an end portion extended to the diaphragm floor and opened to the drywell and a vacuum breaker is mounted to the extended portion of the vent pipe and connected to a fixing pipe for mounting a vacuum breaker to the pedestal, the fixing pipe having one end opened to an inside of the vent pipe.