ML20079N685

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Final Part 21 Rept Re Check Valve Leak in Air Start Sys of Standby Diesel Generators.Initially Reported on 820209. Defective Valves Modified by Replacing Disc Assembly Per Conversion Procedure
ML20079N685
Person / Time
Site: Bellefonte  Tennessee Valley Authority icon.png
Issue date: 01/25/1984
From: Mills L
TENNESSEE VALLEY AUTHORITY
To: James O'Reilly
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
REF-PT21-84-268-000 PT21-84-268, PT21-84-268-000, NUDOCS 8401300300
Download: ML20079N685 (2)


Text

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'l C% TENNESSEE yALLEY. AUTHORITY CHATTANOOGA. TENNESSEE 37401 400 Chestnut Street Tower II

. ,, g g.Ofanuary 5, 1984 BLR3-50-438/82-13 BLRD-50-439/82-13 U.S. Nuclear Regulatory Commission Region II Attn: Mr. James P. O'Reilly, Regional Administrator 101 Marietta Street, NW Suite P900 Atlanta, Georgia 30303

Dear Mr. O'Reilly:

BELLEFONTE NYJCLEAR PLANT UNITS 1 AND 2 - CHECK VALVE LEAX IN AIR START SYSTEM OF STANDBY DIESEL GENERATORS - BLRD-50-438/82-13, BLHD-50-439/82 FINAL REPORT The subject deficiency wac initially mported to NRC-0IE Inspector R. V. Crlenjak on February 9,1982 in accordance with 10 CFR 50.55(e) as NCR BLN MEB 8201. This was followed by our interim reports dated March 3, May 28, and August 30, 1982 and March 29, 1983 Enclosed is our final repor t. We consider 10 CFR Part 21 applicable to this deficiency.

Although in our March 3,1982 letter, TVA had stated that the standby diesel generators at Hartsville Nuclear Plant B would be transferred to the Yellow Creek Nuclear Plant site, these plans have been deferred until further notice.

If you have any questions, please get in touch with R. H. Shell at FTS 858-2688.

Very truly yours, TENNESSEE VALLEY AUTHORITY L. M. Mills, nager Nuclear Licensing Enclosure oc: Mr. Richard C. DeYoung, Director (Enclosure)

Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Records Center (Enclosure)

Institute of Nuclear Power Operations OFFICIAL corv 1100 circle 75 Parkway, Suite 1500 4 [27

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Atlanta, Georgia 30339 8401300300 840125 An Equal Opportunity Employer 8l F

1 ENCLOSURE c, i?

BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 CHECK VALVE LEAK IN AIR START SYSTEM OF STANDBY DIESEL GENE'tATORS NCR BLN MEB 8201 BLRD-50-438/82-13, BLRD-50-439/82-13 10 CFR 50.55(e)

FINAL REPORT Description of Deficiency A check valve identical to those installed by Transamerica Delaval, Incorporated (TDI), in the diesel generator starting air system between the air compressor and the air storage tanks was found to leak daring a saismic qualification test. The function of the valve is to allow the starting air compressor to charge the storage tank, and then prevent backflow once the tanks are d1arged.

TDI was requested to investigate this problem and supply a root cause of the deficiency. TDI has refused to do so.

Safety Implications Failure of the subject check valve could result in the standby diesel generators being unavailable during a loss of offsite power. In the event of an accident, this conli ,lon would adversely affect safe plant operations.

Corrective Action TVA has modified the defective valves by replacing the existing disc assembly per the conversion procedure and revised drawing provided by TDI.

Since the modification to the existing disc assembly is to an internal component of the check valve, the valve's pressure code boundaries are not affected. This modification has been seismically tested and accepted.

TVA had requested that TDI supply us with action required to prevent recurrence. However, they refused to do so in their letter dated December 2, 1982.

TVA has made every effort to ensure that all items procured from this vendor do not have the subject deficiency. Furthermore, TVA will place a note in the vendor files which prohibits TVA from procuring any more diesel generators from this vendor without verifying that this problem has been correc ted.

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