ML16211A188
| ML16211A188 | |
| Person / Time | |
|---|---|
| Issue date: | 05/15/1995 |
| From: | Kress T Advisory Committee on Reactor Safeguards |
| To: | Taylor J NRC/EDO |
| References | |
| Download: ML16211A188 (2) | |
Text
D950515 Mr. James M. Taylor Executive Director for Operations U.S. Nuclear Regulatory Commission Washington, DC 20555-0001
Dear Mr. Taylor:
SUBJECT:
PROPOSED FINAL GENERIC LETTER 95-XX, "VOLTAGE-BASED REPAIR CRITERIA FOR WESTINGHOUSE STEAM GENERATOR TUBES" During the 421st meeting of the Advisory Committee on Reactor Safeguards, May 4-6, 1995, we discussed the subject generic letter. During this meeting, we had the benefit of discussions with representatives of the NRC staff, the Nuclear Energy Institute, and the Southern Nuclear Operating Company. We also had the benefit of the documents referenced.
We provided comments on a draft version of the generic letter in our report dated September 12, 1994. A number of changes have been made in the generic letter as a result of public comments. These changes do not affect our technical assessment that the generic letter provides an acceptable approach to ensure the integrity of tubing subject to axially oriented outside diameter stress corrosion cracking in Westinghouse steam generators with drilled-hole support plates.
In our September 12, 1994 report, we noted that the database for the present empirical correlations of burst pressure, leakage, and bobbin coil voltage appears to be only marginally adequate. Because of this, we believe the staff decision to retain the conservative lower voltage limits of 2 volts for 7/8-inch diameter tubing and 1 volt for 3/4-inch diameter tubing until more experience is gained with the application of the criteria is prudent and appropriate.
In our previous report, we noted that the concern raised in the differing professional opinion on the calculation of the radiological releases during a main steamline break appeared to warrant further consideration. This issue has not yet been resolved, but we believe that timely implementation of the generic letter should proceed to prevent unnecessary tube repairs and reduce staff resources associated with plant-specific reviews. However, the radiological release issue should be addressed in the proposed rule on steam generator tube maintenance and surveillance.
Dr. William Shack did not participate in the Committee's deliberations regarding this matter.
Sincerely, T. S. Kress Chairman
References:
- 1. Memorandum dated April 6, 1995, from Brian Sheron, Director, Division of Engineering, NRR, to John Larkins, Executive Director, ACRS,
Subject:
ACRS Review of Generic Letter (GL) 95-XX, "Voltage-Based Repair Criteria for Westinghouse Steam Generator Tubes"
- 2. ACRS Report dated September 12, 1994, from T. S. Kress, Chairman, ACRS, to Ivan Selin, Chairman, NRC,
Subject:
Proposed Generic Letter 94-XX, "Voltage-Based Repair Criteria for Westinghouse Steam Generator Tubes"