Results of the sixth regular inspection in Shimane Nuclear Power Station

The sixth regular inspection in Shimane Nuclear Power Station was held from March 2 to June 17, 1980. The facilities inspected were the reactor itself, reactor cooling system, instrumentation and control systems, fuel facilities, radiation control facilities, waste disposal facilities, reactor containment facilities, and reserved power generators for emergency. The results of inspection performed on the appearance, disassembling, leakage (rate), functions, performances and others, showed no abnormality. The reconstruction implemented during the inspection includes the replacement of a part of the pipings of stainless steel for reactor coolant treatment system with carbon steel ones for the purpose of preventing the cracks due to stress corrosion, and also the replacement of collet retainer tubes and others of control rod-driving mechanisms with the improved ones provided with the preventive measures against the cracks due to stress corrosion. The installation work for inflammable gas control system was implemented. The inspection works were performed within the permissible dose established by the laws and ordinances. Tables for the exposed dose, its distribution, and the internal exposure for the workers engaged in the regular inspection were added to the report. (Wakatsuki, Y.)