The standard provides criteria for the performance of periodic testing of nuclear power generating station safety systems. The scope of periodic testing consists of functional tests and checks@ calibration verification@ and time response measurements@ as required@ to verify that the safety system performs its defined safety function. Post-maintenance and post-modification testing are not covered by this document. This standard amplifies the periodic testing requirements of other nuclear safety-related IEEE standards. Purpose This standard is intended to aid the user not only in designing a periodic test capability@ but also in defining and optimizing the primary elements of an effective periodic test program (including planning@ performance/acceptance criteria@ procedures@ test intervals@ and documentation).