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:
t APPENDIX B. SODIUM-COOLED FAST REACTOR DESIGN CRITERIA Appendix B to DG-1330, Page B-12 III. Reactivity Control Criterion SFR-DC Title and Content NRC Rationale for Adaption to GDC conditions,” to emphasize that plants are required to maintain a safe shutdown following AOOs as well as postulated accidents. The second sentence of ARDC 26(2) refers to a means of achieving and maintaining shutdown that is important to safety but not necessarily safety related. The second means of reactivity control serves as a backup to the safety-related means and, as such, margins for malfunctions are not required but the second means shall be highly reliable and robust (e.g., meet ARDC 1 -5). “Independent” indicates no shared systems or components with the safety-related means and “diverse” indicates a different design than the safety- related means. The purpose of an independent and diverse means of controlling reactivity is to preclude a potential common cause failure affecting both means of reactivity control, which would lead to the inability to shut down the reactor. The second means of reactivity control does not have to demonstrate that design limits for fission product barriers are met. Additionally, the current GDC 26, third sentence, states that the second reactivity control system shall be capable of reliably controlling 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 SFR 26 APPENDIX B. SODIUM-COOLED FAST REACTOR DESIGN CRITERIA Appendix B to DG-1330, Page B-13 III. Reactivity Control Criterion SFR-DC Title and Content NRC Rationale for Adaption to GDC 28