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:
conditions of normal operation include startup, power operation, hot standby, shutdown (hot and cold), and refueling modes. 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. Application of GDC 10 thus assures that analyses demonstrate, under all operating, shutdown, and refueling modes, that the reactor core and associated coolant, control, and protection systems are designed with sufficient margins to address postulated boron dilution events, so that fuel cladding integrity will be maintained for such postulated events. 2. GDC 15 requires that the reactor coolant system and associated auxiliary, control, and protection systems be designed with sufficient margin to assure that the design conditions of the RCPB are not exceeded during any condition of normal operation, including anticipated operational occurrences. The design conditions (e.g. pressure limits for DRAFT Rev. 2 - April 1996 15.4.6-6 transients) of the RCPB are established to assure its integrity. The RCPB provides a fission product barrier, a confined volume for the inventory of reactor coolant, and flow paths to facilitate core cooling. In PWRs, boron is added to the reactor coolant in sufficient concentrations to effect reactivity control. PWR conditions of normal operation include startup, power operation, hot standby, shutdown (hot and cold), and refueling modes. 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