The reliability and availability of the reactor protection system (RPS) can be improved by using M out of N judg-ment system .By analyzing two quantitative indicators ,the rate of refusal to operate and mal-operation rate ,a strict math-ematical formula and an approximate calculation are stated .The differences of a series of judgment systems are discussed on condition that the unsafe failure probability and the security failure probability are both 0 .1 .Based on given parameters (A , B ,P ,Q):A is upper limit of the refusal rate for the RPS , B is upper limit of the mal-operation rate , P an...
