Document: NUREG-0800
Document ID: 7b7303eb-a3a7-433b-8301-fcaba03194ea
Document Type: srp
Title: - 15.1.4
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070676.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.1.1
CFR Part: 
CFR Title: 

Content:
in the model: a. 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 operating condition which maximizes the consequences of the event. b. 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. c. 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. d. Mitigating systems should be assumed to be actuated in the analyses at setpoints with allowance for instrument inaccuracy in accordance with Regulatory Guide 1.105. Compliance with Regulatory Guide 1.105 is determined by ICSBHICB.34 Technical Rationale The technical rationale for application of these acceptance criteria to reviewing events initiated by an increase in heat removal by the secondary system is discussed in the following paragraphs.35 (a) Compliance with GDC 10 requires that the reactor core and associated coolant, control, and protection systems be designed with appropriate margin to ensure that specified acceptable fuel design limits are not exceeded during any condition of normal operation, including the effects of anticipated operational occurrences. DRAFT Rev. 2 - April 1996 15.1.1-6 GDC 10 is applicable to this section because the reviewer evaluates the consequences of four anticipated operational occurrences that have the potential to exceed allowable thermal design criteria for fuel cladding integrity. These four anticipated operational occurrences involve the transient increase in