Performance based testing of standby equipment

This paper examines some results of calendar time testing of standby equipment (standby pumps and emergency diesel generators) at four nuclear units in the United States with respect to the frequency of testing this standby equipment. Calendar time testing has resulted in some rather high ratios of Tests to Non-Tests actuations of this standby equipment. The paper proposes testing of standby equipment based on performance rather than calendar time. Performance is defined to be the probability of success during actual demands. The proposed testing scheme would use both industry wide data and unit specific data in the calculations of testing frequency. A guideline is proposed which would aid the system engineers in setting the frequency of testing. The proposed testing guideline is a living process which varies with the frequency of actual demands and the probability of success during actual demands