Document: NUREG-0800
Document ID: 40c0bbb1-aed6-41a9-b8ac-ca483637a639
Document Type: srp
Title: - 15.4.5-4
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550007.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.4.4
CFR Part: 
CFR Title: 

Content:
applicant, they are evaluated by the staff for acceptability. The values of parameters used in the analytical model are to be suitably conservative. The following values are considered acceptable: 1. Initial power level is rated output (licensed core thermal power) for the number of loops initially assumed to be operating, plus an allowance of 2% to account for power measurement uncertainty, unless (a) a lower number can be justified through the measurement uncertainty methodology and evaluation, or (b) unless the uncertainty has otherwise been accounted for (see SRP Section 4.4). An analysis to determine the effects of a flow increase must be made for each allowed mode of operation (i.e., one, two or three loops initially operating) or the effects referenced to a limiting case. 2. Conservative scram characteristics are assumed, e.g., maximum time delay with the most reactive rod held out of the core for a PWR and a design conservatism factor of 0.8 times the calculated negative reactivity insertion rate for a BWR, unless (a) a different conservatism factor can be justified through the uncertainty methodology and