Document: NUREG-0800
Document ID: b694ca5b-4dcc-4098-be04-431e0137a936
Document Type: srp
Title: - 15.5.2
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0708/ML070820081.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.5.1
CFR Part: 
CFR Title: 

Content:
dently. The applicant's analysis of events leading to an increase of reactor coolant inventory should be performed using an acceptable analytical model. If other analytical methods are proposed by the applicant, these methods are evaluated by the staff for acceptability. For new generic methods, the reviewer performs an evaluation of the new method as part of its review under this SRP section. The values of parameters used in the analytical model should be suitably conservative. The following values are considered acceptable for use in the model: 1. 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. 15.5.1-15.5.2-5 Revision 2 - March 2007 The number of loops operating at the initiation of the event should correspond to the operating condition which maximizes the consequences of the event. 2. 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. 3. 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. Technical Rationale The technical rationale for application of these acceptance criteria to the areas of review addressed by this SRP section is discussed in the following paragraphs: 1. Compliance with GDC 10 requires that the reactor core and associated coolant, control, and protection systems be designed with appropriate margin to ensure that fuel design limits are not exceeded during any condition of normal operation, including AOOs. The requirements of GDC 10 apply to the CVCS malfunction events, since power level could conceivably increase