Document: NUREG-0800
Document ID: 91fee075-c567-438d-bf9f-47be3177b457
Document Type: srp
Title: ENGINEERED SAFETY FEATURES MATERIALS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070453.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.1.1
CFR Part: 
CFR Title: 

Content:
corrosive environment, the probability of failure can be significantly reduced. Our recommended minimum pH is somewhat higher than the Oak Ridge recommendation of a minimum of 6.5. B. Branch Technical Position CMEBThe criteria for pH level of postaccident emergency coolant water to reduce the 131 probability of stress-corrosion cracking of austenitic stainless steel components, nonsensitized or sensitized, nonstressed or stressed, are as follows: 1. Minimum pH should be 7.0. 2. For the spray water recirculated from the containment sump, the higher the pH in the 7.0 to 9.5 range, the greater the assurance that no stress corrosion cracking will occur. See 6.1.1-21 DRAFT Rev. 2 - April 1996 SRP Section 6.5.2 for additional water chemistry requirements related to fission product removal. 3. If a pH greater than 7.5 is used, consideration should be given to the hydrogen generation problem from corrosion of aluminum in the containment. C. Evaluation Findings The controls on the pH and chemistry of the reactor containment sprays and ECCS solutions meet the staff positions on postaccident chemistry requirements for PWR emergency coolant water. It also meets the requirements of GDC 14 for assuring the low probability of abnormal leakage or failure of the reactor coolant pressure boundary and safety-related structures. We conclude that the proposed pH for emergency coolant water is acceptable. D. References 1. D. D. Whyte and L. F. Picone, "Behavior of Austenitic Stainless Steel in Post Hypothetical Loss of Coolant Environment," WCAP-7798-L, Westinghouse Nuclear Energy Systems, November 1971 (NES Proprietary Class 2).132 2. J. C. Griess and E. E. Creek, "Design Considerations of Reactor Containment Spray Systems - Part X, The Stress Corrosion Cracking of Types 304 and 316 Stainless Steel in Boric Acid Solutions," ORNL-TM-2412, Part X, Oak Ridge National Laboratory, May 1971.133 DRAFT Rev. 2 - April 1996 6.1.1-22 [This Page Intentionally Left Blank] SRP Draft Section 6.1.1