Document: NUREG-0800
Document ID: 6aed9d14-682e-4421-ba5e-a1fcc9263878
Document Type: srp
Title: NUREG-0800
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0631/ML063190011.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6
CFR Part: 
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Content:
ld be made to the U.S. Nuclear Regulatory Commission, Washington, DC 20555, Attention: Reproduction and Distribution Services Section, or by fax to (301) 415-2289; or by email to DISTRIBUTION@nrc.gov. Electronic copies of this section are available through the NRC's public Web site at http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr0800/, or in the NRC's Agencywide Documents Access and Management System (ADAMS), at http://www.nrc.gov/reading-rm/adams.html, under Accession ## ML063190011. U.S. NUCLEAR REGULATORY COMMISSION STANDARD REVIEW PLAN BRANCH TECHNICAL POSITION 6-1 pH FOR EMERGENCY COOLANT WATER FOR PRESSURIZED WATER REACTORS REVIEW RESPONSIBILITIES Primary - Organization responsible for the review of component integrity issues related to engineered safety features Secondary - None A. BACKGROUND To establish the minimum value of pH in postaccident containment sprays in pressurized water reactors (PWRs), the NRC staff has reviewed the available information and recommended the criteria listed in the branch technical position below. The minimum pH value of 7.0 follows from the Westinghouse report conclusion that, in ECCS solutions adjusted with NaOH to pH 7.0* or greater, no cracking should be observed at chloride concentrations up to 1000 ppm during the time of interest. Figure 7 of the Westinghouse report shows that the time for initiation of cracking of sensitized and nonsensitized U-bend specimens of Type 304 austenitic stainless steel in solutions of 7.0 pH having 100 ppm chloride was 7-1/2 months and 10 months, respectively. BTP 6-1.2 March 2007 The great majority of tests reported in the Oak Ridge report were performed with pH of 4.5, and only two tests were conducted with pH values other than 4.5. Some cracking was observed at pH 7.5 in the sensitized 304 stainless steel U-bend specimens after 2 months exposure to pH 7.5 and chloride concentration of 200 ppm. All of the 316 stainless steel specimens showed no evidence of cracking.