Document: NUREG-0800
Document ID: 41b2cf88-b6dc-4005-939a-cf3fb1a561d2
Document Type: srp
Title: INADVERTENT DECREASE IN BORON CONCENTRATION IN THE REACTOR
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0703/ML070380222.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.4.6
CFR Part: 
CFR Title: 

Content:
n dilution events (one or more times during the life of the nuclear power unit) without other concurrent failures or incidents, regulatory requirements for AOOs apply to their analyses or evaluations. Uncertainties of quantification or measurement of relevant boron dilution event parameters are verified by analyses including appropriate design margins. To address single failures not attributable to a common cause/mode, the control rod system is designed for a specified minimum shutdown margin without credit for the functioning of the highest worth control rod. 15.4.6-7 Revision 2 - March 2007 Thus, GDC 26 assures that analyses demonstrate whether the control rods reliably control reactivity changes with appropriate margin for malfunctions like stuck rods under applicable conditions of normal operation (startup and power operation), including the effects of postulated boron dilution events, to maintain fuel cladding integrity. III. REVIEW PROCEDURES 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 procedures below are for both the construction permit (CP) and operating license (OL) reviews. During the CP review, the values of system parameters and setpoints in the analysis are preliminary in nature and subject to change. At the OL review, final values should be used in the analysis, and the reviewer should compare these to the limiting safety system settings in the proposed technical specifications. 1. The SAR describes moderator dilution transients reviewed by the staff for the occurrences leading to the initiating events. The sequence of events, from initiation to a stabilized