This standard provides design and operational criteria for the performance of periodic testing of nuclear power generating station safety systems. The scope of testing covered consists of functional tests@ checks@ calibration verification@ and time response measurements. Criteria are also provided for determining system operational availability@ status@ and necessary documentation; and@ for establishing test intervals@ and test procedures during operation. Routine preventive maintenance is not covered by this document. The criteria herein define in greater detail the periodic testing requirements of IEEE Std 603-1977@ IEEE Std 279-1971@ and IEEE SM 308-1974.