Purpose and Scope The primary purposes of this Standard are to specify minimum design@ testing and maintenance requirements for the isolation of fluid systems which penetrate the primary containment of light water reactors. These fluid systems include piping systems (including instrumentation and control) for all fluids entering or leaving the containment. Electrical systems are not included. The provisions for containment isolation impose additional requirements which are not required for the fluid system function. This Standard does not consider any isolation requirements that may exist for controlled leakage areas either enclosing the primary containment or contiguous to the primary containment. For the purposes of this Standard@ containment isolation is defined as closure of isolation provisions in lines penetrating the containment for the event of the loss-of-coolant accident within the containment or any other accident which calls for actuation of the same containment isolation provisions. The containment isolation provisions are@ therefore@ provided for this accident. If such an accident occurred@ fluid systems penetrating the containment would be isolated except those which are engineered safety features or engineered safety feature related. Other accidents may require isolation of a specific fluid system or group of systems. The isolation provisions for such accidents are defined as accident isolation@ and in many instances the provisions of this Standard apply. The objective of containment isolation shall be to allow the normal or emergency passage of fluids through the containment boundary while preserving the integrity of the containment boundary if required to prevent or limit the escape of fission products as a result of a postulated loss-of-coolant accident. This Standard presents requirements and conditions that are needed for the isolation of the containment and covers requirements for isolation barriers@ their operators@ and connecting piping between isolation barriers. The standard does not cover penetration assemblies@ protection systems@ and power supplies. The design requirements in this Standard consider: the system isolation function; isolation function testing; leakage rate monitoring and testing; and maintenance. This Standard gives general requirements or refers to other standards@ codes@ and regulations for the following requirements: fire protection; protection against natural phenomenon such as earthquake@ tornado@ or flood; environmental conditions such as normal operation@ maintenance@ testing@ and postulated accidents (including the dynamic effects from missiles@ pipe whip@ and discharging fluids); and separation criteria.