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:
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 accounted for. 15.4.6-4 Rev. 1 - July 1981 The RSB reviewer confirms that analyses are included for a boron dilution incident occurring during each of the following plant initial conditions: refueling, startup, power operation (automatic. control and manual modes), hot standby, and cold shutdown. The refueling condition should consider cases when the reactor vessel head is removed and the coolant is drained to the elevation of the hot leg piping. For each such incident reviewed, all possible causes must have been considered by the applicant and justification presented that the cause selected for analysis is the one that allows the operator the least time to take corrective action. With the aid of the EICSB reviewer, the timing of the initiation of those protec- tion, engineered safety, and other systems needed to limit the consequences of each boron dilution incident to acceptable levels is reviewed. The RSB reviewer compares the predicted variations of system parameters with various trip and system initiation setpoints. the ICSB reviewer evaluates automatic initiation, actuation delays, possible bypass modes, interlocks, and the feasibility of manual operation where the SAR states that operator action is needed or expected. To the extent deemed necessary, the RSB reviewer evaluates the effects of single active failures of systems and components that may affect the course of the transient. This phase of the review uses the system review procedures described in the standard review plans for Chapters 5, 6, 7, 8, and 9 of the SAR. In particular, the redundancy of alarms that alert the operator to the unplanned dilution is confirmed. The mathematical models used by the applicant to evaluate core performance and reactivity status are reviewed by RSB to determine if these