ML20094C897

Part 21 Rept Re Valves Being Supplied W/Bushings Made of Babbitt Graphalloy Instead of Graphite.Corrective Actions: Ring-O-Valve Spa Supplied Replacement Nickel Graphalloy Bushings

ML20094C897
Person / Time
Site:	Pilgrim
Issue date:	11/01/1995
From:	Matthew Smith GENERAL ELECTRIC CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
REF-PT21-95 MFN-#248-95, NUDOCS 9511030028
Download: ML20094C897 (5)

Text

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GENERAL INFORMATION or OTHER EVENT NUMBER: 29535 LICENSEE: GENERAL ELECTRIC NOTIFICATION DATE: 11/01/95 CITY: SAN JOSE REGION: 4 NOTIFICATION TIME: 09:22 [ET]

COUNTY: STATE: CA EVENT DATE: 11/01/95 LICENSE #: AGREEMENT: Y EVENT TIME: 00:00[PST]

DOCKET: LAST UPDATE DATE: 11/01/95 NOTIFICATIONS NRC NOTIFIED BY: NOEL SHIRLEY HQ OPS OFFICER: JOSEPH SEBROSKY VERN HODGE NRR EMERGENCY CLASS: NOT APPLICABLE 10 CFR SECTION:

CCCC 21.21 UNSPECIFIED PARAGRAPH EVENT TEXT GENERAL ELECTRIC IS ISSUING A PART 21 REPORT DUE TO IMPROPER VALVE PACKING MATERIAL USED IN VALVES THAT WERE SUPPLIED TO THE PILGRIM NUCLEAR POWER PLANT.

GE NUCLEAR ENERGY (GE-NE) BOUGHT FROM RING-O VALVE spa OF ITALY, AND PROVIDED TO THE BOSTON EDISON COMPANY PILGRIM PLANT, FOUR GATE VALVES INTENDED FOR SAFETY RELATED APPLICATIONS (TWO IN THE HPCI SYSTEM AND TWO IN THE RWCU SYSTEM). AS PART OF THE VALVE DELIVERY IMPROPER VALVE PACKING BUSHINGS WERE SUPPLIED WHICH CONTAINED BABBITT, A LEAD BEARING ALLOY WHICH IS KNOWN TO CAUSE EMBRITTLEMENT IN STAINLESS STEEL. THIS DID NOT MEET THE GE-NE VALVE SPECIFICATION.

THE IMPROPER MATERIAL WAS IDENTIFIED DURING THE INSTALLATION PERIOD AND THE BUSHINGS WERE REPLACED WITH BUSHINGS CONTAINING AN ACCEPTABLE MATERIAL. THE VALVES WERE NOT YET PLACED INTO NUCLEAR SERVICE AT THE TIME OF DISCOVERY.

GE-NE HAS EVALUATED THE SAFETY SIGNIFICANCE OF THE IMPROPER BUSHING MATERIAL IN ALL FOUR VALVES AND HAS CONCLUDED THAT FOR THE VALVES IN THE HPCI SYSTEM, A SIGNIFICANT SAFETY CONCERN DID NOT EXIST. HOWEVER GE-NE ENGINEERING HAS NOT BEEN ABLE TO CONCLUSIVELY RULE OUT THE POSSIBILITY THAT i THE POTENTIAL CONSEQUENCES OF HAVING THIS MATERIAL IN THE RWCU SYSTEM WOULD l NOT RESULT IN A SUBSTANTIAL SAFETY CONCERN AND HAS THEREFORE ELECTED TO l REPORT THIS UNDER 10CRF21. GE-NE HAS NOT SUPPLIED THIS VALVE TO ANY OTHER '

NUCLEAR POWER PLANT TO DATE.

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i November 1,1995 i

9546nrc. doc MFN-#248-95 Document Control Desk j ll Nuclear Regulatory Commission l Washington, D. C. 20555

Subject:

10CFR Part 21, Reportable Condition, improper Valve Packing Bushing 7

Material '

This letter is to inform the NRC of a reportable defect per 10 CFR Part 21, as reported to I

! Mr. Joe Sebrosky the duty officer in the NRC's emergency operations center by  !

. N.C. Shirley for M.A. Smith, Manager, Safety Evaluations Project, on October November 1,1995.

GE Nuclear Energy (GE-NE) bought from Ring-O valve spa of Italy, and provided to the 130ston Edison Company Pilgrim Plant, four gate valves intended for safety related j applications (two in the HPCI system and two in the RWCU system). As part of the valve ,

delivery improper vale packing bushings were supplied which contained Babbitt, a lead bearing alloy which is known to cause embritdement in stainless steel. This did not meet the GE-NE valve specification. The improper bushing material was identified during the i installation period, and the bushings were replaced with bushings containing an

acceptable material. The valves were not yet placed into nuclear service at the time of discovery. GE NE has evaluated the cafety significance of the improper bushing material

in all four valves and has concluded 1 hat, for the valves in the HPCI system, a significant safety concern did not exist. Howevgr, GE NE Engineering has not been able to conclusively rule out the possibility that the potential consequencesof having this material in service in the RWCU systkm would not result in a substantial safety concern,

] and has therefore elected to report tbis under 10CFR21. GE-NE has not supplied this valve to any other nuclear power plant to date. Ringo Valve spa ofItaly has implemented internal measures to assure strict compliance with GE-NE specifications requirements in all future orders of ! hese valves.

Very truly yours, M. A. Smith, Manager Safety Evaluations ProjectQ 3 0 0 2 ] ,

M/t 187, (408) 925-10]9

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Attachment cc: G. C. Cwalina (NRC-NRR/ DISP / PSIB)

C. R. Shockley (GE-NE)

PRC File 1

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t ATTACHMENT ,

REPORTABLE CONDITION (i) Name and address of the indisidualinforming the Commission:

M.A. Smith, Manager, Safety Evaluations Project, GE Nuclear Energy,175 Curtner i

Avenuc, SanJose, CA 95125 (ii) Identification of the facility, the activity, or the basic component supplied for such  ;

facility or such activity within the United States which fails to comply or contains defect:  ;

GE-NE supplied two gate valve s, designed and manufactured by Ring-O Valve spa ofItaly, to the Pilgrim Nuclear Power Station. These valves were intended to function as inboard and outboard containment isolation valves in the Reactor j Water Cleanup (RWCU) syste n effluent line.

(iii) Identification of the firm cons tructing the facility or supplying the basic componentwhich fails to con 1 ply or contains the defect:

GE Nuclear Energy, SanJose, California (iv) Nature of the defect or failure to comply and safety hazard which is created or could be created by such defect or failure to comply:

The RWCU inboard and outboard containmentisolation valves are normally open and are closed upon receipt o'f an isolation signal to conserve reactor coolant and to isolate the containment to .:ontrol release of radioactivity to the atmosphere.

The GE valve specification required that non-metallic materials comply with trace material control requirement; and also requires the bushings, which are in contact with the valve stem, to be made of graphite. The valves were supplied with bushings made of Babbitt Graphalloy, which is a 50% graphite matrix that is impregnated with roughly 50% Babbitt, a lead bearing alloy. The Graphalloy bushing is a 50% graphite mttrix that is impregnated with roughly 50% Babbitt, a lead bearing alloy. This Lead alloy has a melting temperature of approximately  ;

400 *F, whereas the actual setvice l temperature is expected to be close to 550 *F.

Under thse conditions the l ead alloy could attack the grain boundaries of the neighboring ferrous parts and result in embrittlement and cracking, For a normally open valve, the valve disc is continually buffeted by flow induced vibration. Since the stem is chnnected to the disc, the stem is also afTected by this ,

vibration. Should an embri}tled stem crack, the crevice would become a stress  ;

concentration point. Such drevice could propagate under continuous vibration, t

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l and the stem could fracture due to fatigue cycles. The valve stem connects the valve actuator to the disc. If the stem is fractured, the actuator would no longer be j capable of either opening or closing the disc. The disc would begin to drop into  :

the flow stream, however it might not fall to the fully closed position as the  !

differential pressure across tbe disc might induce a friction force that is greater than the weight of the disc.

l Since a partially closed disc might not reduce the flow through rA e vaive by a noticeable, amount a fractured stem might not be detected under normal plant operation. Although this sequence of events is highly unlikely, especially with the i existing leak detection system sensitivity and the low probability of the RWCU pipe break, a decision was still mac e to report this under 10CFR21.

(v) Date on which the information of such defect or failure to comply was obtained:

October XXXX 1995 I

(vi) In the case of a basic component which contains a defect or failure to comply, the number and locations off all ! uch components in use at, supplied for, or being j supplied for one or more facilities or activities subject to the regulations in this l l

part:

Pilgrim Nuclear Plant (vii) The corrective action which lias been,is being, or will be taken; the name of the individual or organization responsible for the action; and the length of time that has been or will be taken to complete the action:

Upon discovery of the incorrect bushing material installation, Ring-O Valve spa supplied replacement Nickel Graphalloy bushings; these were approved and installed by GE-NE prior to placing the valves into nuclear service. In additon, Ring-O Valve spa of Italy has impicmented a policy to identify specific and detailed ordering data includjng a " Nuclear Plant Application" statement incorporating media and design temperature and pressure information for parts ordered for application and dse in valves being supplied for use in nuclear plant applications. l (viii) Any advice related to the defqct or failure to comply about the facility, activity, or basic component that has been,is being, or will be given to purchasers or licensecs:

Since the subject valves were ordered solely for the Pilgrim Station, and since Ring-O Valve spa of Italy has changed their ordering policy, there is no planned communication to otherlicensees.

l S/S'd A933N3 80313rN 39 LJe95:40 S6, 10 AON