This standard provides PPS requirements for nuclear power plants and guidance in the areas of AAC power source interfaces with the PPS, physical independence of the PPS power and control circuits, and expanded PPS criteria for multi-unit stations. The purpose of this standard remains unchanged. This standard is being revised and an annex provided to define the attributes of the PPS that are required to ensure PPS reliability when offsite power is supplied by an entity other than the nuclear utility, such as an ISO. It is intended to provide utilities with the necessary guidance and structure to ensure PPS reliability in a deregulated environment and ensure the nuclear plant(s) licensing reqiurements and design criteria are not compromised.