Document: NUREG-0800
Document ID: 73148264-0cb4-4b1b-8586-3105a0a46c78
Document Type: srp
Title: REACTOR WATER CLEANUP SYSTEM (BWR)
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0631/ML063190009.pdf
Revision Date: 2023-06
Chapter: 5
Section ID: 5.4.8
CFR Part: 
CFR Title: 

Content:
he containment structure and contains radioactive material. Failure of a system component as the result of a natural phenomenon could result in release of reactor water until the containment isolation valves close and in release of radioactive materials outside the containment structure. Meeting the requirements of GDC 2 minimizes the probablity that a failure of the RWCS will occur, thus decreasing the potential for release of reactor coolant or other radioactive materials outside the containment structure. 3. Compliance with GDC 14 requires that the reactor coolant pressure boundary shall be designed, fabricated, erected, and tested to ensure extremely low probability of abnormal leakage, rapidly propagating failure, and gross rupture. GDC 14 applies because the RWCS is used to maintain reactor cooling water chemistry. Thus, reactor cooling water chemistry and levels of impurities must be monitored to avoid deterioration of the reactor coolant pressure boundary by general corrosion or by intergranular stress corrosion cracking (IGSCC). IGSCC results from the simultaneous occurrence of aggressive water environment, susceptible material, and tensile stress conditions. Should general corrosion or IGSCC occur, leakage, failure, or gross rupture could result. The RWCS provides a means of controlling reactor cooling water chemistry and levels of impurities. In addition, parts of the RWCS connected directly to the reactor coolant system must be fabricated to the same standards as the reactor coolant system. Meeting the requirements of GDC 14 minimizes the probability of failure of the reactor coolant pressure boundary as a result of general corrosion or IGSCC, thus decreasing the potential for a loss-of-coolant accident. 4. Compliance with GDC 60 requires that the nuclear power unit design shall include a suitable means to control the release of radioactive materials in gaseous and liquid effluents and to handle radioactive solid wastes produced during normal reactor