Document: NRC Regulatory Guide
Document ID: 9c99a4b7-8619-41f0-b716-262bfdb03941
Document Type: regulatory_guide
Title: Developing Principal Design Criteria for Non-Light Water Reactors + HISTORY - HISTORY 02/2017 – DG-1330 , Proposed Revision 0
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1630/ML16301A307.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.232
CFR Part: 
CFR Title: 

Content:
ilding are addressed by new Criterion 71 (design basis) and Criterion 72 (provisions for periodic testing and inspection). 17 Electric power systems. Electric power systems shall be provided to permit functioning of structures, systems, and components important to safety. The safety function for the systems shall be to provide sufficient capacity, capability, and reliability to ensure that (1) specified acceptable system radionuclide release design limits and design conditions of the reactor helium pressure boundary are not exceeded as a result of anticipated operational occurrences and (2) vital functions that rely on electric power are maintained in the event of postulated accidents. The onsite electric power systems shall have sufficient independence, redundancy, and testability to perform their safety functions, assuming a single failure. A reliable power system is required for SSCs during postulated accident conditions. Power systems shall be sufficient in capacity, capability, and reliability to ensure vital safety functions are maintained. The emphasis is placed on requiring reliability of power sources rather than prescribing how such reliability can be attained. The reference to onsite vs. offsite electric power systems was deleted to provide for those reactor designs that do not depend on offsite power for the functioning of SSCs important to safety. The text related to “…supplies, including batteries, and the onsite distribution system,” was deleted to allow increased flexibility in the design of offsite power systems for advanced reactor designs. However, such onsite systems are still expected to remain capable of performing assigned safety functions during accidents as a condition of requisite reliability. “Reactor coolant pressure boundary” has been relabeled as “reactor helium pressure boundary” to conform to standard terms used for mHTGRs. The specified acceptable fuel design limit has been replaced with the SARRDL. The discussion on