Document: NUREG-0800
Document ID: d4441736-a9bb-45c2-8d16-d23e8312ab08
Document Type: srp
Title: CHEMICAL AND VOLUME CONTROL SYSTEM MALFUNCTION THAT
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070717.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.4.6
CFR Part: 
CFR Title: 

Content:
vity control. PWR conditions of normal operation include startup, power operation, hot standby, shutdown (hot and cold), and refueling modes. The control rods may reduce reactivity only when withdrawn and operable (i.e. during startup and power operation), however. Because of the frequency with which boron dilution events are anticipated to occur (one or more times during the life of the nuclear power unit) without other concurrent failures or incidents, regulatory requirements associated with anticipated operational occurrences are applied to their analyses/evaluation. Inherent uncertainties associated with quantification or measurement of relevant boron dilution event parameters are verified by analyses to be addressed through inclusion of appropriate design margins. To address single failures not attributable to a common cause/mode, the control rod system is designed such that a specified minimum shutdown margin exists without credit for the functioning of the highest worth control rod. 15.4.6-7 DRAFT Rev. 2 - April 1996 Application of GDC 26 thus assures that analyses demonstrate that the control rods are capable of reliably controlling reactivity changes with appropriate margin for malfunctions such as stuck rods, under applicable conditions of normal operation (startup and power operation), including the effects of postulated boron dilution events, such that fuel cladding integrity will be maintained. III. REVIEW PROCEDURES The procedures below are used during both the construction permit (CP) and operating license (OL) reviews. During the CP review, the values of system parameters and setpoints used in the analysis will be 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 included in the proposed technical specifications. The descriptions of moderator dilution transients presented in the SAR are reviewed by RSBSRXB regarding