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 Std 308-1974.