Document: NRC Regulatory Guide
Document ID: 7fa0e9f9-cb40-463b-adc5-53fe2057e43f
Document Type: regulatory_guide
Title: Fresh and Spent Fuel Pool Criticality Analysis + HISTORY - HISTORY 08/2020 – DG-1373 , Proposed Revision 0
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2018/ML20182A788.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.240
CFR Part: 
CFR Title: 

Content:
ed in the NRC’s regulations, and the NRC’s requirements take precedence over the international guidance. DG-1373, Page 7 C. STAFF REGULATORY GUIDANCE 1. The NRC staff considers the guidance in NEI 12-16, Revision 4, with clarifications and exceptions, acceptable as a means for demonstrating compliance with the requirements in 10 CFR 50.68(b). The NRC staff provides these clarifications and exceptions to certain technical positions and statements in NEI 12-16, Revision 4, as discussed below: a. Section 1.4 states that the double contingency principle, as applied to criticality accidents, means, in part, that licensees do not need to consider the simultaneous occurrence of two independent and unlikely conditions. The example provided discusses conditions that are controlled through technical specification requirements. A licensee or applicant may consider certain conditions to be unlikely conditions, such as the possibility that a burnable absorber panel may not have been correctly installed. However, if no controls or documents exist to preclude such a condition, then the licensee or applicant should treat it as part of the normal condition. b. The last paragraph of Section 1.6 discusses the concept of using a “graded” licensing approach to use risk insights, which is consistent with current licensing practices. Licensees or applicants should establish how they will maintain any excess safety margins being used to justify assumptions or simplifications when they update the criticality analyses, using their approved methodology, to accommodate changes in the fuel storage characteristics. c. Section 2 discusses acceptance criteria for fresh fuel vault storage and states that one of the situations for which an evaluation does not need to be performed in accordance with 10 CFR 50.68(b) is when a licensee has been granted an exemption to 10 CFR 70.24. This only applies if the licensee maintains the conditions upon which the exemption was based. If the conditions