Document: NUREG-0800
Document ID: ecb92ac6-97df-4e4b-a20a-81638c2d573b
Document Type: srp
Title: - 15.3.4
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350157.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.3.3
CFR Part: 
CFR Title: 

Content:
uld be performed using an acceptable analytical model. The equations, sensitivity studies, and models described in Refer- ences 7 through 11 are acceptable. If other analytical methods are proposed by the applicant, these methods are evaluated by the staff for acceptability. For new generic methods, the reviewer requests an evaluation. There are certain assumptions regarding important.parameters used to describe the initial .plant conditions and postulated system failures which should be used. These are listed below: i. The initial power level is taken as the licensed core thermal power for the number of loops initially assumed to be operating plus an allowance of 2% to account for power measurement uncertainties, unless a lower power level can be justified by the applicant. The number of loops operating at the initiation of the event should correspond to the operat- ing condition which maximizes the consequences of the event. ii. Conservative scram characteristics are assumed, i.e., for a PWR maximum time delay with the most reactive rod held out of the core, and for a BWR a design conservatism factor of 0.8 times the calculated negative reactivity insertion rate. iii. The core burnup is selected to yield the most limiting combination of moderator temperature coefficient, void'coefficient, Doppler coefficient, axial power profile, and radial power distribution. III. REVIEW PROCEDURES The procedures below are used during both the construction permit (CP) and operating license (OL) reviews. During the CP review, the values of system parameters and setpoints used in the analysis will be preliminary in nature and subject to change. At the OL review stage, final values should be used in the analysis, and the reviewer should compare these to the limiting safety system settings included in the proposed technical specifications. The applicants' analyses of the rotor seizure and shaft break events are reviewed by RSB regarding the occurrences leading to the initiating