United States Nuclear Regulatory Commission - Protecting People and the Environment

Accession No.:  9511030028

November 1, 1995
95-06nrc.doc
MFN-#248-95

Document Control Desk
Nuclear Regulatory Commission
Washing[on, D. C.  20555

Subject:  10CFR Part 21, Reportable Condition, Improper Valve Packing
          Bushing Material

This letter is to inform the NRC of a Deportable defect per 10 CFR Part
21, as reported to 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 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 vale 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 bushing 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 the potential
consequences, of having this material in service in the RWCU system would
not result in a substantial safety concern, and has therefore elected to
report this under 10CFR21. GE-NE has not supplied this valve to any other
nuclear power plant to date.  Ring-O Valve SpA of Italy has implemented
internal measures to assure strict compliance with GE-NE specifications
requirements in all future orders of these valves.

Very truly yours,

M.  A.  Smith, Manager
Safety Evaluations Project
M/C 187, (408) 925-1019

Attachment

cc.  G.  C.  Cwalina (NRC-NRR/DISP/PSIB)
     C.  R.  Shockley (GE-NE)
     PRC File

                               ATTACHMENT

                          REPORTABLE CONDITION

(i)       Name and address of the individual informing the Commission:

          M.A.  Smith, Manager, Safety Evaluations Project, GE Nuclear
          Energy, 175 Curtner Avenue, San Jose, 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 valves, designed and manufactured by
          Ring-O Valve SpA of Italy, to the Pilgrim Nuclear Power
          Station.  These valves were to function as inboard and outboard
          containment isolation valves in the Reactor Water Cleanup
          (RWCU) system effluent line.

(iii)     Identification of the firm constructing the facility or
          supplying the basic component which fails to comply or contains
          the defect:

          GE Nuclear Energy, San Jose, 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 containment isolation valves are
          normally open and are closed upon receipt of an isolation
          signal to conserve reactor coolant and to isolate the
          containment to control release of radioactivity to the
          atmosphere.

          The GE valve specification required that non-metallic materials
          comply with trace material control requirements 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 matrix
          that is impregnated with roughly 50% Babbitt, a lead bearing
          alloy. This Lead alloy has a melting temperature of
          approximately 400 Degrees F, whereas the actual service
          temperature is expected to be close to 550 Degrees F. Under
          these conditions the lead alloy 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 connected
          to the disc, the stem is also affected by this vibration.
          Should an embrittled stem crack, the crevice would become a
          stress concentration point. Such crevice could propagate under
          continuous vibration,

          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 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 the disc might
          induce a friction force that is greater than the weight of the
          disc.

          Since a partially closed disc might not reduce the flow through
          the valve 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 existing leak
          detection system sensitivity and the low probability of the
          RWCU pipe break, a decision was still made to report this under
          10CFR21.

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

          October XXXX 1995

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

          Pilgrim Nuclear Plant

(vii)     The corrective action which has 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 addition, Ring-O
          Valve SpA of Italy has implemented a policy to identify
          specific and detailed ordering data including a "Nuclear Plant
          Application" statement incorporating media and design
          temperature and pressure information for parts ordered for
          application and use in valves being supplied for use In nuclear
          plant applications.

(viii)    Any advice related to the defect or failure to comply about the
          facility, activity, or basic component that has been, is being,
          or will be given to purchasers or licensees:

          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 other
          licensees.

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