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. 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). Revision Standard - Superseded. 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. Remarks: Revision of IEEE Std 338-1987