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:
Regulatory Guide and 10 CFR 50.63 provides assurance that the CVCS is capable of performing their intended functions to support core cooling in the event of an SBO. III. REVIEW PROCEDURES The reviewer will select material from the procedures described below, as may be appropriate for a particular case. These review procedures are based on the identified SRP acceptance criteria. For deviations from these acceptance criteria, the staff should review the applicant’s evaluation of how the proposed alternatives provide an acceptable method of complying with the relevant NRC requirements identified in Subsection II. The design of the CVCS will vary with each PWR plant supplier. For example, some PWR designs use the CVCS charging pumps as high pressure safety injection pumps as part of the ECCS, while in other PWR designs, the CVCS is not a part of the ECCS and not relied upon to perform safety function for mitigation of the design basis events. Also, most PWR designs use CVCS to provide seal injection for the reactor coolant pump seal, while other designs, such as Westinghouse’s AP1000, have sealless, canned-motor, reactor coolant pumps that do not require seal injection from the CVCS. For the purpose of this SRP section, a typical system is assumed for use as a guide. It is assumed that the typical system consists of a regenerative heat exchanger to cool the letdown flow from the RCS before processing through the demineralizers (or ion exchangers) and to reheat it prior to reinjection into the RCS, demineralizers, and filters for removal of suspended and dissolved impurities, high pressure charging pumps to inject makeup flow into the RCS, a volume control tank for system surge capacity and makeup volume, a boron makeup and storage system to provide neutron absorber to the RCS as needed, evaporators and tanks for boron recovery and demineralized water makeup, and a boron thermal regeneration subsystem to minimize the quantity of waste water and allow reactivity