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:
down the reactor (Ref. 27). The staff changed control rods to “means” in recognition that advanced reactor designs may not rely on control rods to rapidly shut down the reactor (e.g., alternative system designs or inherent feedback mechanisms may be relied upon to perform this function). Additionally, “specified acceptable fuel design limits” is replaced with “design limits for fission product barriers” to be consistent with the AOO acceptance criteria. ARDC 10 and ARDC 15 provide the appropriate design limits for the fuel and reactor coolant boundary, respectively. A non-LWR may not necessarily shut down rapidly (within seconds) but the shutdown should occur in a time frame such that the fission product barrier design limits are not exceeded. In regards to safety class, the capability to shut down the APPENDIX A. ADVANCED REACTOR DESIGN CRITERIA Appendix A to DG-1330, Page A-9 III. Reactivity Control Criterion ARDC Title and Content NRC Rationale for Adaptions to GDC reactor is identified as a function performed by safety-related SSCs in the 10 CFR 50.2 definition of safety-related SSCs. (2) Current GDC 27 states that the reactivity control systems shall be designed to have a combined capability of reliably controlling reactivity changes to assure that, under postulated accident conditions and with appropriate margin for stuck rods, the capability to cool the core is maintained. Reliably controlling reactivity, as required by GDC 27, requires that the reactor achieve and maintain safe, stable conditions, including subcriticality, using only safety related equipment with margin for stuck rods (Ref. 26). The first sentence of ARDC 26 (2) refers to the safety-related means (systems and/or mechanisms) to achieve and maintain safe shutdown. “Maintain safe shutdown” indicates subcriticality in the long term or an equilibrium condition naturally achieved by the design. The staff changed “reactivity control systems” to “means” in recognition that