Document: NUREG-0800
Document ID: 853719df-a6ea-408b-8d43-5956155abc38
Document Type: srp
Title: and 8.3.2.
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1007/ML100740246.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8.3.1
CFR Part: 
CFR Title: 

Content:
ditions. 6. GDCs 33, 34, 35, 38, 41, and 44 set forth requirements for the safety systems for which the access to both offsite and onsite electric power sources must be provided. Compliance with these criteria requires that capability be provided for reactor coolant makeup during small breaks (GDC 33), residual heat removal (GDC 34), emergency core cooling (GDC 35), containment heat removal (GDC 38), containment atmosphere cleanup (GDC 41), and cooling water for structures, systems, and components important to safety (GDC 44). These systems must be available during normal and accident conditions, as required by the specific system. GDC 33 requires that the system design shall be such that, for preferred power system operation (if standby power is not available), the system safety function can be accomplished using the piping, pumps, and valves to maintain coolant inventory during normal reactor operations. For the offsite power system, these requirements are met if the minimum design required by GDC 17 is provided. GDCs 34, 35, 38, 41, and 44 require that safety system redundancy shall be such that, for preferred power system operation (if standby power is not available), the system safety function can be accomplished, assuming a single failure. For passive reactor design applications, such as the AP 1000, the potential risk contribution of design basis event is minimized by not requiring ac power sources for design-basis events (DBEs). Passive reactor designs incorporate passive safety-related systems for core cooling and containment integrity, and therefore, do not depend on the electric power grid connection and grid stability for safe operation. They are designed to automatically establish and maintain safe shutdown conditions after DBEs for 72 hours, without operator action, following a loss of both onsite and offsite ac power sources. Consequently, passive reactor designs are not required to meet the requirements of GDCs 33, 34, 35, 38, 41, and 44 for 72