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:
prior to reactor trip, the event could cause DNB to occur. However, this is not likely, since (1) core pressure increases, and (2) the reactor protection system automatically trips the reactor when it senses a reduction in thermal margin. Like the inadvertent operation of ECCS, the CVCS malfunction is not expected to pose a concern with respect to RCS and main steam system overpressurization. The CVCS malfunction event should meet the same acceptance criteria as the inadvertent operation of ECCS. The event is mitigated (i.e., terminated) when the operator shuts off the charging flow. The CVCS malfunction event is expected to be less limiting (i.e., to fill the pressurizer more slowly) than the inadvertent operation of ECCS event. This is due to some coolant shrinkage that occurs when the reactor is tripped, and to the lower charging flow rate that is delivered when the charging pumps are not operating as part of the ECCS. III. REVIEW PROCEDURE The reviewer will select material from the procedures described below, as may be appropriate for a particular case. These review procedures are based on the identified SRP acceptance criteria. For deviations from these acceptance criteria, the staff should review the applicant’s evaluation of how the proposed alternatives provide an acceptable method of complying with the relevant NRC requirements identified in Subsection II. The applicant's description of events leading to an increase in reactor coolant inventory is reviewed with respect to the occurrences leading to the initiating event. The sequence of events, from initiation until a stabilized condition is reached, is reviewed to determine the following: 1. The extent to which normally operating plant instrumentation and controls are assumed to function. 2. The extent to which plant and reactor protection systems are required to function. 15.5.1-15.5.2-8 Revision 2 - March 2007 3. Credit taken for the functioning of normally operating plant systems; 4. Operation of