Document: NRC Regulatory Guide
Document ID: da269da5-7390-4252-b08f-bdb7aeb8beaf
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:
ant accidents (LOCAs) that may not apply to every design. For example, helium is not needed in a mHTGR to remove heat from the core during postulated accidents and does not have the same importance as water does to LWR designs to ensure that fuel integrity is maintained. Therefore, a specific reference to LOCAs is not applicable to all designs. LOCAs may still require analysis in conjunction with postulated accidents if they are relevant to the design. If an mHTGR design proposes using a direct power cycle in which one or more very high-speed, very high-energy gas turbines are APPENDIX C. MODULAR HIGH-TEMPERATURE GAS-COOLED REACTOR DESIGN CRITERIA Appendix C to DG-1330, Page C-3 I. Overall Requirements Criterion mHTGR-DC Title and Content NRC Rationale for Adaptions to GDC ruptures in nuclear power units may be excluded from the design basis when analyses reviewed and approved by the Commission demonstrate that the probability of fluid system piping rupture is extremely low under conditions consistent with the design basis for the piping. located inside the reactor helium pressure boundary. The presence of one or more very high-energy turbines inside the primary helium pressure boundary creates the potential that a catastrophic dynamic failure of the gas turbine (e.g., at power) could result in the consequential catastrophic failure of the primary system pressure boundary caused by the failure of rotating turbine components. To account for the possibility of an mHTGR design that locates high-energy gas turbines inside the reactor helium pressure boundary, the mHTGR-DC language in the area of prevention, protection, and mitigation of turbine dynamic failure is strengthened to support such a power conversion system design approach. 5 Sharing of structures, systems, and components. Same as GDC II. Multiple Barriers Criterion mHTGR-DC Title and Content NRC Rationale for Adaptions to GDC 10 Reactor design. The reactor system and associated heat removal, control, and