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:
ARDC The structural and equipment cooling systems shall be designed to permit appropriate periodic functional testing to assure (1) the structural and leaktight integrity of their components, (2) the operability and the performance of the system components, and (3) the operability of the systems as a whole and, under conditions as close to design as practical, the performance of the full operational sequences that bring the systems into operation for reactor shutdown and postulated accidents, including operation of associated systems. This renamed mHTGR-DC accounts for advanced reactor system design differences to include possible cooling requirements for SSCs important to safety. Specific mention of “pressure” testing has been removed yet remains a potential requirement should it be necessary as a component of “…appropriate periodic functional testing...” of cooling systems. A non-leaktight system may be acceptable for some designs provided that (1) the system leakage does not impact safety functions under all conditions, and (2) defense in depth is not impacted by system leakage. “Active” has been deleted in item (2) because appropriate operability and performance tests of system components are required regardless of their active or passive nature. The LOCA reference has been removed to provide for any postulated accident that might affect subject SSCs. The GDC reference to electric power was removed. Refer to the rationale for ARDC 17 regarding electric power systems. V. Reactor Containment Criterion mHTGR-DC Title and Content NRC Rationale for Adaptions to GDC 50 Containment design basis. Not applicable to mHTGR. This criterion is not applicable to the mHTGR. The mHTGR designs do not have a “pressure retaining reactor containment structure” but instead rely on a multibarrier functional containment configuration to control the release of radionuclides. See the mHTGR-DC 16 rationale. APPENDIX C. MODULAR HIGH-TEMPERATURE GAS-COOLED REACTOR DESIGN