AFTER-STOP OPERATING METHOD FOR FAST BREEDER

摘要

PURPOSE:To cool a reactor core in safety by confirming the operation states of respective pony motors at the emergency stoop of a nuclear reactor and placing pony motors which can sound operation in fast operation if even one pony motor can not perform the sound operation. CONSTITUTION:Respective pony motor pole quantity changeover switches 20 are switched normally to small pole number sides. If the nuclear reactor stops in emergency owing to some abnormality, respective cooling material circulation pumps 9a - 9d are switched from main motors 14a - 14d to the pony monitors 15a - 15d. If the emergency stop is caused because an external power source is lost, emergency diesel power generators 17 and 19 are actuated automatically, but if the power generator 17 can not be actuated, the operation by two pony motors 15a and 15b connected to it becomes impossible. Then a pony motor pole number switching decision circuit 21 detects the failure in the operation and switches the switches 20 to large pole number sides. Consequently, other two pony motors 15c and 15d rotate fast to secure a necessary reactor core flow rate.