Document: NUREG-0800
Document ID: dcd79479-0633-4d67-ba17-e369513aa55d
Document Type: srp
Title: SPECTRUM4 OF ROD EJECTION ACCIDENTS (PWR)
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350410.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.4.8
CFR Part: 
CFR Title: 

Content:
ogical evaluation by AEB. The radiological criteria used in the evaluation of control rod ejection accidents (PWRs) are given in Appendix B of Regulatory Guide 1.77 (Ref. 2). III. REVIEW PROCEDURES 1. Review of the applicant's analyses, showing that the first of the acceptance criteria above is met, proceeds as follows: a. A spectrum of initial conditions is considered, which must include both zero-power and full-power conditions, at beginning and end of a reactor fuel cycle (BOC and EOC), to assure examination of upper bounds on possible fuel damage. Initial full-power conditions should include the uncertainties in the calorimetric measurement of power. b. From the initial conditions of (a) and from control rod patterns, the limiting rod worth is determined. Where confirmation is considered necessary the reviewer may calculate, as an audit, the worth of limiting rods. c. Reactivity coefficient values corresponding to the limiting initial conditions must be used at the beginning of the transient. The reviewer checks the reactivity coefficient curves used by the applicant with those reviewed by the CPB under SRP Section 4.3. The two coefficients of most interest are the Doppler and moderator coefficients.. If no three-dimensional space-time calculation is performed, the reactivity feedback must be conservatively weighted to account for the variation in the missing dimension(s). d. The reviewer inspects the control rod insertion assumptions which include: trip parameters, trip delay time, rod velocity curve, and differential rod worth. Trip parameters and delay time are reviewed under SRP Section 7.2. Control rod worth is checked by the reviewerI for consistency with the review performed under SRP Section 4.3. e. The applicant's analytical methods are reviewed. The reviewer may use the results of previous case work, if the analytical methods have been previously reviewed and approved by the staff. Otherwise 15.4.8-2 Rev. 2 - July 1981 he must perform a de novo review