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:
mal leakage of RCCS coolant to locations other than the exhaust structure may be acceptable provided that (1) the RCCS leakage does not impact safety functions under all conditions, and (2) functional containment is not impacted by RCCS leakage. APPENDIX C. MODULAR HIGH-TEMPERATURE GAS-COOLED REACTOR DESIGN CRITERIA Appendix C to DG-1330, Page C-19 IV. Fluid Systems Criterion mHTGR-DC Title and Content NRC Rationale for Adaptions to GDC Some mHTGR RCCS designs will provide continuous passive operation without need for a requirement to test the operation sequence that brings the system into operation; “if applicable” is included to recognize this contingency. Reference to the operation of applicable portions of the protection system, structural and equipment cooling water systems, and power transfers is considered part of the more general “associated systems” for operability testing of the system as a whole. The criterion was modified to reflect the passive nature of the mHTGR RCCS and the need to verify the ability to transition the RCCS from active mode (if present) to passive mode during postulated accidents. 38 Containment heat removal. 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. 39 Inspection of containment heat removal system. 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. 40 Testing of containment heat removal system. Not applicable to mHTGR. This criterion is not applicable to the mHTGR. The mHTGR designs do not have a “pressure retaining