Document: NUREG-0800
Document ID: 8b6b2506-1305-4f5c-9cd6-725a1d90c61c
Document Type: srp
Title: CHEMICAL AND VOLUME CONTROL SYSTEM MALFUNCTION THAT RESULTS IN A
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350402.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.4.6
CFR Part: 
CFR Title: 

Content:
eginning-of- life (BOL) condition. (iv) All fuel assemblies are installed in the core. (v) A conservatively low value is assumed for the reactor coolant volume. (vi) For analyses during refueling, all control rods are withdrawn from the core. (vii) For analyses during power operation, the minimum shutdown margin allowed by the technical specifications (usually l%) is assumed to exist prior to the initiation of boron dilution. (viii) For each event analyzed, a conservatively high reactivity addition rate is assumed taking into account the effect of increasing boron worth with dilution. (ix) Conservative scram characteristics are assumed, i.e., maximum time delay with the most reactive rod held out of the core. III. REVIEW PROCEDURES The procedures below are used during both the construction permit (CP) and operat- ing license (OL) reviews. During the CP review, the values of system parameters and setpoints used in the analysis will be preliminiary 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 included in the proposed technical specifications. The descriptions of moderator dilution transients presented in the SAR are reviewed by RSB regarding the occurrences leading to the initiating events. The sequence of events, from initiation until a stabilized condition is reached, is reviewed.to ascertain: 1. The extent to which normally operating plant instrumentation and controls are assumed to function. Particularly important are the alarms which alert the operator to the unplanned boron dilution. 2. The extent to which the plant and reactor protection systems are required to function. 3. The credit taken for the functioning of normally operating plant systems. 4. The operation of engineered safety systems that is required. 5. The extent to which operator actions are required. 6. The appropriate margin for malfunctions, such as stuck rods are