Document: NUREG-0800
Document ID: 784779aa-bf3d-4538-b7b3-4358a3e2a604
Document Type: srp
Title: - 15.4.5-8
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:
Revision 2 - March 2007 4. The operation of engineered safety systems that are required. 5. The extent to which operator actions are required. 6. That appropriate margin for malfunctions, such as stuck rods, is accounted for. 7. That instrumentation uncertainties of system and operating parameters are appropriately accounted for. If the SAR or DCD states that a particular core flow AOO is not as limiting as some other similar AOO, the reviewer evaluates the justification presented by the applicant. The applicant should present a quantitative analysis in the SAR or DCD of the increase in flow AOO that is determined to be most limiting. For this AOO, the reactor systems reviewer, with the aid of the instrumentation and controls reviewer, reviews the timing of the initiation of protection, engineered safety feature, and other systems needed to limit the consequences of the core flow increase AOO to acceptable levels. The reviewer compares the predicted variation of system parameters with various trip setpoints. The review of Chapter 7 of the SAR or the corresponding chapter of the DCD confirms that the instrumentation and control system design is consistent with the requirements for safety system actions for these events. To the extent required, the reviewer evaluates the effect of single active failures of safety systems and components that may alter the course of the AOO. This phase of the review uses the system review procedures described in the SRP sections for Chapters 5, 6, 7, and 8 of the SAR or the corresponding chapters of the DCD. The reviewer considers and evaluates the possibility of a single failure that would permit the loop isolation valves to open prior to startup of a pump in an idle loop (for those plants with loop isolation valves). If this could occur, the core flow rate increase would not be limited by the rate at which the valve opens, and the resulting rate of reactivity insertion could be greater than for other AOOs of this group. The