Document: NUREG-0800
Document ID: 0b529a75-fd6e-4e39-9791-94f199dfcf56
Document Type: srp
Title: CHEMICAL AND VOLUME CONTROL SYSTEM (PWR) (INCLUDING BORON
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0701/ML070160660.pdf
Revision Date: 2023-06
Chapter: 9
Section ID: 9.3.4
CFR Part: 
CFR Title: 

Content:
unit, an orderly shutdown and cooldown of the remaining units. The CVCS may be designed to provide essential safety-related functions necessary for continued safe operation of the unit(s), such as the ability to provide seal injection to the RCPs or the capability to maintain RCS chemistry to prevent gross failure of the reactor coolant pressure boundary (RCPB). The CVCS must be 9.3.4-8 Revision 3 - March 2007 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 RCPB will have an extremely low probability of abnormal leakage, of rapidly propagating failure and of gross rupture. Failure of the RCPB may be postulated where the mechanisms of general corrosion and/or stress corrosion cracking induced by impurities in the reactor coolant are present. The CVCS maintains acceptable purity levels in the reactor coolant through the removal of insoluble corrosion products and dissolved ionic material by filtration and ion exchange. In addition, the CVCS maintains proper RCS chemistry by controlling 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 RCPB will be minimized, thereby maintaining the integrity of the RCPB. 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 (AOO). Portions of the CVCS may be relied upon to provide negative reactivity