ML20202G974

Final Part 21 & Deficiency Rept Re Failure of BIF Butterfly Valve Seats.Initially Reported on 820511.Seat Failures Reworked.Informal Tests Performed After Seat Replacement Show That Leakage Corrected

ML20202G974
Person / Time
Site:	Bellefonte
Issue date:	03/28/1986
From:	Gridley R TENNESSEE VALLEY AUTHORITY
To:	Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
REF-PT21-86, REF-PT21-86-128-000 PT21-86-128, PT21-86-128-000, NUDOCS 8604150052
Download: ML20202G974 (4)

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d. -o TENNESSEE VALLEY AUTHORITY I

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J h' March 28, 1986 BLRD-50-438/82-37 BLRD-50-439/83-08 U.S. Nuclear Regulatory Commission Region II Attn: Dr. J. Nelson Grace, Regional Administrator 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 1

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Dear Dr. Grace:

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BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - FAILURE OF BIF BUTTERFLY VALVE SEATS  ;

- BLRD-50-438/82-37, BLRD-50-439/83 FINAL REPORT l The subject deficiency was initially reported to NRC-OIE Inspector .

R. V. Celenjak on May 11, 1982 in accordance with 10 CFR 50.55(e) as NCR 1819. This was followed by our interim reports dated June 8, and I October 29, 1982; February 8, May 25, and July 28, 1983; September 18, 1984; April 25 and October 9, 1985. Related NCRs 2170, 2186, and 2187 were included in our second interim report and NCR 2231 was included in our fourth interim report. Enclosed is our final report. We consider 10 CFR Part 21 applicable to this deficiency.

If you have any' questions concerning this matter, please got in touch with R. H. Shell at FTS 858-2688.

Very truly yours, TENNESSEE VALLEY AUTHORITY R. L. Gridl y Manager of icensing Enclosure ec: Mr. James Taylor, Director (Enclosure)

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

Institute of Nuclear Power Operations 1100 circle 75 Parkway, suite 1500 Atlanta, Georgia 30339 I E604150052h$O 38 pDR ADOCK PDR S

1 An Equal Opportunity Employer lI J %E.27 -

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ENCLOSURE BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 FAILURE OF BIF BUTTERFLY VALVE SEATS BLRD-50-438/82-37 and BLRD-50-439/83-08 NCRs 1819, 2170, 2186, 2187, AND 2231 10 CFR 50.55(e)

FINAL REPORT Description of Deficiency.

The following butterfly valves, manufactured by BIF, a unit of General Signal Corporation, West Warwicke, Rhode Island, which are used in the essential air (RJ) system were determined to be leaking in excess of an acceptable rate.

BIF Serial UNID No. Mark No. Contract No. Item _No. No.

1-RJ-VTAC-50B 3BWWO471-00-20 76K30-86163-3 577 N-49445-10 1-RJ-VTAC-44B 3BWWO471-00-15 76K30-86163-3 576 N-49445-7 1-RJ-VTAC-27A 3BWWO471-00-15 76K30-86163-3 576 N-49445-2 Further investigation revealed that the rubber seats had failed due to damage (i.e., the seats were cut and portions were missing).

Subsequent to the identification of the deficient valves cited above on NCR 1819, the following essential raw cooling water (ERCW) (KE) system valves also supplied by BIF were determined to be deficient and documented as such on the indicated nonconformance reports (NCRs).

NCR 217_0 The valve seat on 2KE-VTAC-255A had pulled loose from the valve body.

l l NCR 2_186, i

Valve 1KE-VTAC-252A was removed to inspect for leakage; it was discovered that the valve seat had pulled loose from the valve body.

NCR 2187 j l

When ERCW valve 1KE-VTAC-255A was removed to inspect leakage of 1KC-MHS-006A heat exchanger, it was discovered that the valve seat had pulled loose from the valve body. ,

NCR 2231 ERCW valves IKE-VTAC-113B and 2KE-VTAC-113B were removed to inspect for leakage; it was discovered that the valve seats were cut.

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TVA has determined that BIF butterfly valves are currently incorporated into-the design of twelve safety-related systems at BLN: component cooling (KC),

essential raw cooling water (KE), spent fuel cooling (NM), high-pressure fire protection (RF), service air (RH), essential air (RJ), auxiliary building (AB) common area environmental control (VC), AB trained area air conditioning (A/C)

(VE) AB common area A/C (VF), liquid radwaste disposal (WL), makeup l demineralizer (VM), and sample and water quality (YQ).

The causes of this deficiency were:

! 1. Valve seats were manufactured or installed improperly on air service (e.g., RH and RJ) system valves.

2. In the liquid service (e.g., KE and KC) systems, valve seats deteriorated during storage or were damaged due to improper storage or damaged during system flushing.

Safety Implications _

If valve 1-RJ-VTC-50B had been placed into service in the deficient condition

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described and the service air system pressure boundary degraded, a single active failure of isolation valve 1-RJ-IFCV-045B could result in a potentially significant loss of pressure in the RJ system. The RJ system is a safety-related system that supplies air to essential pneumatically operated

• instruments, controls, and operators. Consequently, a significant loss of pressure in the RJ system could be a condition adverse to the safe operation of the plant.

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Corrective Actions TVA has approximately 400 BIF butterfly valves procured for use on safety-related systems in Bellefonte Nuclear Plant (BLN) units 1 and 2. To date, approximately 45 documented cases of seat failures have occurred. These seat failures have been reworked by either TVA or the manufacturer, and informal tests performed after seat replacement show that leakage was corrected.

i Section II of the ASME Code or Appendix J of the ASME Code provide the rules {

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and requirements for in-service testing to assess operational readiness of '

valves.Section II places valves in several categories; included are:

CateRory A - Valves for which seat leakage is limited to a specific maximum amount in the closed position for fulfillment of their function.

CateRory B - Valves for which seat leakage in the closed position is inconsequential for fulfillment of their function.

Section II requires leak rate testing of Category A valves and specifies corrective action to be taken if leakage is unacceptable.

Appendix J includes requirements for in-service testing, which in some cases are applied to valves not covered by Section II (e.g., air system valves).

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TVA has identified or will identify valves requiring in-service testing in accomplishing our Section II and Appendix J compliance program.

To date, TVA has identified ten (10) valves per reactor unit manufactured by BIF, which are either Category A or Appendix J valves, that will require in-service leak tests. In addition, these valves require leakage testing during the Preoperation Testing Program.

• The majority of BIF valves at BLN has been installed. In accordance with the

' requirements of Section II of the ASHE code and the preoperational test program, each Category A valve will be subjected to the appropriate system seat leak test and performance test per TVA standard system procedures. Seats will be replaced as necessary, based on the results of the testing. TVA is also evaluating other information, such as seat shelf life, to develop preventative maintenance and long term lay-up programs in order to enhance component integrity.

In addition, BIF informed TVA that the subject seats have a finite shelf life that is bounded by storage conditions. Therefore, storage and preventive maintenance for Category A valves will be reviewed, evaluated, and incorporated as appropriate into the site program by July 31, 1986.

The above program of leak and performance testing and storage condition l

evaluation will verify that any Category A BIF butterfly valve has acceptable seat leakage rates and will provide necessary notice of seat leakage problems that may develop. Any leakage of BIF butterfly valves that are not included in Category A will be discovered and corrected in accordance with normal maintenance programs. TVA expects that any seat damage incurred during future system flush activities will also be detected and repaired during normal maintenance activities.

With respect to the deficiencies noted on the RJ system valves, TVA discussed the deficiency with a manufacturer's representative who visited the site and inspected the valves. He concluded that the shape of the installed seats was concave instead of convex, which indicated an improper installation or a manufacturing problem. He indicated that BIF manufacturing procedures and installation procedures have been revised to prevent recurrence of the deficiency.

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