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:
rolling the rate of changes resulting from planned, normal power changes (including xenon burnout) to assure acceptable fuel design limits are not exceeded. Staff has identified this as an operational requirement that is not necessary to ensure reactor safety provided a design complies with ARDC 26(1). Therefore, this sentence is not retained in ARDC 26. 27 Combined reactivity control systems capability. Same as ARDC DELETED—Information incorporated into ARDC 26 28 Reactivity limits. The reactor core, including the reactivity control systems, shall be designed with appropriate limits on the potential amount and rate of reactivity increase to ensure that the effects of postulated reactivity accidents can neither (1) result in damage to the reactor helium pressure boundary greater than limited local yielding, nor (2) sufficiently disturb the core, its support structures, or other reactor vessel internals to impair significantly the capability to cool the core. “Reactor coolant pressure boundary” has been relabeled as “reactor helium pressure boundary” to conform to standard terms used for mHTGRs. The list of “postulated reactivity accidents” has been deleted. Each design will have to determine its postulated reactivity accidents based on the specific design and associated risk evaluation. 29 Protection against anticipated operational occurrences. Same as GDC APPENDIX C. MODULAR HIGH-TEMPERATURE GAS-COOLED REACTOR DESIGN CRITERIA Appendix C to DG-1330, Page C-15 IV. Fluid Systems Criterion mHTGR-DC Title and Content NRC Rationale for Adaptions to GDC 30 Quality of reactor helium pressure boundary. Components that are part of the reactor helium pressure boundary shall be designed, fabricated, erected, and tested to the highest quality standards practical. Means shall be provided for detecting and, to the extent practical, identifying the location of the source of reactor helium leakage. Means shall be provided for detecting ingress of moisture, air,