ML19208D336
| ML19208D336 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 07/26/1979 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| NUDOCS 7909280252 | |
| Download: ML19208D336 (1) | |
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TENNESSEE VALLEY AUTHORITY
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CHATTANOOGA. TENNESSEE 37401 400 Chestnut Street Tower II
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- 7. [, 0 b July 26, 1979 Mr. James P. O'Reilly, Director Office of Inspection and Enforcement U.S. Nuclear Regulatory Comission Region II - Suite 3100 101 Marietta Street Atlanta, Georgia 30303
Dear Mr. O'Reilly:
OFFICE OF INSPECTION t.ND ENFORCEMENT BULLETIN 79-01A - RII:JPO 50-259, -260, -296 - BROWNS FERRY NUCLEAR PLANT UNITS 1, 2, AND 3 As a result of additional review of OIE Bulletin 79-OlA, TVA is providing a response to the subject bulletin. The results of our investigaticus at Browns Ferry are enclosed.
Very truly yours, TENNESSEE VALLEY AUTHORITY
. M. Mills, ager Nuclear Regulation and Safety Enclosure cc:
Mr. Noman C. Moseley, Director (Enclosure)
Division of Reactor Operations Inspection Office of Inspection and Enforcement U.S. Nuclear Regulatory Comission Washington, DC 20555 1044 188 gs %.T1 7909280 q,
An Ecual Optortunity Employer
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ADDITIONAL RESPONSE AS A RESULT OF REVIEWING OIE BULLETIN 79-OlA DEFICIENCIES IN THE ENVIRONMENTAL QUALIFICATION OF ASCO SOLENOID VALVES BROWNS FERRY NUCLEAR PLANT ACTION ITEMS:
1.
Determine whether or not ASCO solenoid valves are used or planned for use in safety-related syste=s at your facility (ies).
2.
If such valves are used or planned for use, identify the safety system involved and determine that:
(a) valves which could b'e subjected to a LOCA environment are qualified to that environment.
Specifically that no parts made of acetal plastic or Buna "N" materials or Class "A",
"B", or "F" solenoid coils are used in ssh valves; (b) a preventive maintenance program is being conducted such that the solenoid coil, the manual operator (if applicable), and the resilient parts of the valves are being replaced in accordance with the time period established by the manufacturer and documented as the qualified life of the assembled component.
RESPONSE
AsstatedinourreplytoIEBulletin79-01datedJune11,19f9,(J.E.C111 eland to N. C. Moseley) ASCO solenoid valves (catalog No. WPHIX8300B86F) are used on the automatic depressurization system (ADS) relief valves at Browns Ferry Nuclear Plant. These solenoid valves have stainless steel seats, are operated by a coil having a Class H insulation rating (as indicated by the "HT" in the catalog number), and the coil is enclosed in a NEMA "6" enclosure (as indicated by the "WP" in the catalog number). The environmental qualification of these solenoid valves was shown in our response to IE Bulletin 79-01. Discussions with ASCO have revealed, however, that our solenoid valves may have 0-rings made of Buna "N" elastomer material.
Our main steam relief valve (MSRV) maintenance procedures will be =odified that those solenoid valves on all MSRV's are maintained in to ensure accordance with the manufacturer's recommendations.
1-o Our engineers have disassembled and examined one of the ASCO solenoid valves and have concluded that even if the Buna "N" 0-rings were to become brittle, the small amount of possible leakage would not affect the proper operation of the solenoid valve.
In light of the fact that the ASCO solenoid valves installed have stainless steel seats, as opposed to the resilient seats in the ASCO valve that failed (as discussed in Bulletin 79-01A), and the conclusions of our engineers that the valve will continue to operate properly e' if the Buna "N" gaskets become brittle, we plan no additional actions at this time.
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