ML20214K527

First Interim Deficiency Rept Re Missing Internal Lockwelds on Anchor Darling swing-check Valves.Initially Reported on 861016.Two Subj Valves Found Thus Far Inspected & Found Acceptable.Final Rept to Be Submitted 1 Yr Before Fuel Load

ML20214K527
Person / Time
Site:	Bellefonte
Issue date:	11/17/1986
From:	Gridley R TENNESSEE VALLEY AUTHORITY
To:	Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
NUDOCS 8612020334
Download: ML20214K527 (3)

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. L TENNESSEE VALLEY AUTHORITY CHATTANOOGA. TENNESSEE 37401 SN 15 g %kut Place BLRD-50-438/86-11

@M NOV 17 886 BLRD-50-439/86-09 U.S. Nuclear Regulatory Conunission

-Region II Attention: Dr. J. Nelscn Grace, Regional Administrator 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323

Dear Dr. Grace:

BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - MISSING INTERNAL LOCKWELDS ON ANCHOR DARLING SWING-CHECK '/ALVES - BLRD-50-438/86-11 AND BLRD-50-439/86 FIRST INTERIM REPORT The subject deficiency was initially reported to NRC-OIE Inspector Art Johnson on October 16, 1986 in accordance with 10 CFR 50.55(e) as SCR BLN MEB 8622.

Enc 1.osed is our first interim report. We expect to submit our final report on ot before one year before fuel load of unit 1.

If you have any questions, please call D. L. Terrill at 615/751-3274 extension 265.

Very truly yours, TENNESSEE VALLEY AUTHORITY

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R. L. Gridi . Director Nuclear Safety and Licensing Enclosure cc (Enclosure):

Mr. Jamed Taylor, Director Mr. G. G. Zech Office of Inspection and Enforcement Director, TVA Projects U.S. Nuclear Regulatory Commission U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Region II 101 Marietta Street, NW, Suite 2900 Records Center Atlanta, Georgia 30323 Institute of Nuclear Power Operations 1100 circle 75 Parkway, Suite 1500 Atlanta, Georgia 30339 h

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An Equal Opportunity Employer =

. l ENCLOSURE BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 MISSING INTERNAL LOCKWELDS ON ANCHOR DARLING SWING-CHECK VALVES SCR BLN MEB 8622 BLRD-50-438/86-ll AND BLRD-50-439/86-09 10 CFR 50.55(e)

FIRST INTERIM REPORT Description of Deficiency A potential problem exists on certain Anchor Darling (A/D) check valve designs. Inspections at other nuclear plants have revealed that internal lockwelds were sometimes found missir.g and were possibly omitted during the

! ' manufacturing process.

TVA was notified by A/D in their letters dated July 25 and December 9, 1985 that lockwelds were discovered missing on several A/D 150-pound and 300-pound check valves at Palo Verde and V. C. Summer Nuclear Plants. Similar valves have been purchased by TVA for various plants. No actual failure or discovery of missing lockwelds has been reported at a TVA facility.

Safety Implications Missing lockwelds for hinge pin set screws, hinge support capscrews, disc nut pins, and the hinge support / bonnet interface could cause uncontrolled leakage or internal valve parts could be disengaged and block flow downstream.

In order to maintain the geometry necessary for tight shutoff, the hinge support should be lockwelded to the bonnet. If this weld is missing the hinge support could conceivably shift, thus preventing the valve from seating properly. Such a failure could prevent one or more of these valves from performing its/their safety function thereby degrading the safe operation of the plant.

Interim Progress Only two valves have been identified to date that have been sent to BLN. One check valve, transferred from Hartsville Nuclear Plant (HTN), has been -

installed in unit 1 Essential Raw Cooling Water (ERCW) system train A which supplies water to the auxiliary control room air conditioning. The other

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valve transferred from HTN has not been installed and is located in the i warehouse. Both valves identified to date have been inspected and are in full compliance with the lockweld requirements as specified on the vendor

drawings. At this time, these two valves are the only valves that have been identified as transferred to BLN. TVA is continuing its investigation to determine if any other A/D valves at BLN are affected by this condition.

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TVA has obtained from A/D (in their letter dated October 13, 1986) a list of all affected drawings. Valves, covered by these drawings, which may have been received at BLN will be identified. TVA will then inspect the subject valves to determine if valves were assembled and lockwelded in accordance with the applicable drawings. TVA will install any missing lockwelds in accordance with approved procedures.

Our final report on this item will be provided by one year before fuel load of unit 1 and will identify any defective valves which may have been received at BLN.

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