Document: NUREG-0800
Document ID: d4d35b7c-b4e5-4cb4-8dd9-1b7edddf0ad6
Document Type: srp
Title: CHEMICAL AND VOLUME CONTROL SYSTEM (PWR) (INCLUDING BORON
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070537.pdf
Revision Date: 2023-06
Chapter: 9
Section ID: 9.3.4
CFR Part: 
CFR Title: 

Content:
ide seal injection to the RCPs or the capability to maintain RCS chemistry to prevent gross failure of the reactor coolant pressure boundary. The CVCS must be designed such that the ability to perform these and other designated safety-related functions are not compromised for each unit regardless of equipment failures or other events that may occur in another unit. Meeting the requirements of GDC 5 provides assurance that unacceptable effects of equipment failures or other events occurring in one unit of a multi-unit site will not propagate to the unaffected unit(s). 4. GDC 14 requires assurance that the reactor coolant pressure boundary will have an extremely low probability of abnormal leakage, of rapidly propagating failure and of gross rupture. Failure of the reactor coolant pressure boundary may be postulated where the mechanisms of general corrosion and/or stress corrosion cracking induced by impurities in the reactor coolant are present. Acceptable purity levels in the reactor coolant are maintained by the CVCS system through the removal of insoluble corrosion products by filtration and through the removal of dissolved ionic material by ion exchange. In addition, the CVCS maintains proper RCS chemistry by allowing for the control of total dissolved solids, pH, oxygen concentration and halide concentrations within the acceptable ranges. Meeting the requirements of GDC 14 enhances plant safety by providing assurance that the probability of corrosion-induced failure of the reactor coolant pressure boundary will be minimized, thereby maintaining the integrity of the reactor coolant pressure boundary. 5. GDC 29 requires that the reactivity control systems be designed to assure an extremely high probability of accomplishing their safety functions in the event of anticipated operational occurrences. Portions of the CVCS system may be relied upon to provide negative reactivity addition by injection of boric acid to the reactor coolant system. Injection of sufficient