Document: NUREG-0800
Document ID: 6997f9d9-dedc-49d7-ac15-7615c1bd9713
Document Type: srp
Title: SPECTRUM OF ROD DROP ACCIDENTS (BWR)
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550015.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.4.9
CFR Part: 
CFR Title: 

Content:
subsection II acceptance criteria (e.g. fuel rod failure, peak pressure, long-term cooling) and maximizing fuel rod failures due to each failure mechanism (e.g. pallet/cladding mechanical interaction versus dry-out) may differ. 1. Review of the applicant's analyses showing that the first acceptance criterion is met proceeds as follows: A. The reviewer verifies whether the applicant considers for this event a spectrum of initial conditions that cover the range of time-in-cycle and initial power levels. B. The reviewer verifies the use of maximum expected individual control rod worths. The nominal control rod withdrawal pattern and abnormal patterns not precluded by an instrumentation system accepted under SRP Chapter 7 review must be considered in the development of control rod worth criteria. C. The reviewer determines whether an acceptable and conservative function describes the control rod worth as a function of control rod position and whether the control rod position as a function of time is suitably conservative. D. The reviewer determines whether conservative reactivity coefficients, notably the Doppler, are compatible with those described in SRP Section 4.3. E. The reviewer ensures that the scram action is represented conservatively in the integral scram worth curve (SRP Section 4.3) and in the scram delay time. F. The reviewer checks the analytical methods for previous review and approval. The reviewer also may perform an independent calculation. The applicant's methods should account conservatively for all major reactivity feedback mechanisms. 2. The reviewer inspects the results of the calculation of maximum reactor pressure for compliance with the acceptance criterion in subsection II of this SRP section (the reviewer may do an audit calculation when appropriate). 3. For the second acceptance criterion the number of fuel rods with clad failure is determined (for the SRP section 15.0.3 reviewer evaluating the radiological consequences of the control rod