United States Nuclear Regulatory Commission - Protecting People and the Environment

95150
ACCESSION #: 9507030139

                   VIRGINIA ELECTRIC AND POWER COMPANY
                        RICHMOND, VIRGINIA 23261
                              June 27, 1995

U. S. Nuclear Regulatory Commission          Serial No.     95-318
Attention: Document Control Desk             NL&P/DAS
Washington, D.C. 20555                       Docket Nos.    50-280
                                                            50-281
                                             License Nos.   DPR-32
                                                            DPR-37

Gentlemen:

VIRGINIA ELECTRIC AND POWER COMPANY
SURRY POWER STATION UNITS 1 AND 2
NOTIFICATION OF DEFECT IN ACCORDANCE WITH 10 CFR 21

Virginia Electric and Power Company (Virginia Power) has identified
several incidents of instrument drift in excess of specified limits for
the Rosemount pressure transmitter Model 1154SH9.  In accordance with 10
CFR 21.21, the following information is provided as written notification
of an existing defect.

     1.   Name and address of the individual or individuals informing the
          Commission.

          Mr. R. F. Saunders
          Vice President - Nuclear Operations
          Virginia Electric and Power Company
          5000 Dominion Boulevard
          Glen Allen, Virginia 23060

     2.   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 a defect.

          Surry Power Station Units 1 and 2
          Rosemount Pressure Transmitter Model 1154SH9

     3.   Identification of the firm constructing the facility or
          supplying the basic component which fails to comply or contains
          a defect.

          Rosemount Aerospace Inc.
          1256 Trapp Road
          Eagan, MN 55121
          Attn:  Mr. K. Ewald
                 Business Unit Manager

     4.   Nature of the defect or failure to comply and the safety hazard
          which is created or could be created by such defect or failure
          to comply.

          In February 1995, Virginia Power initiated a root cause
          evaluation (RCE) to determine the cause of calibration
          discrepancies identified with the pressurizer pressure
          protection transmitters.  During this evaluation, three spare
          Model 1154SH9 transmitters were tested in an oven to determine
          if they were affected by temperature variations.  As a result
          of this testing and readings taken in the process racks,
          Virginia Power concluded that some Rosemount Model 1154SH9
          pressure transmitters were exhibiting instrument drift greater
          than specification.  This drift was due to changes in
          containment ambient temperature between calibration during
          shutdown and normal operations.  Affected transmitters
          exhibited a zero shift in the negative direction of between 6
          and 15 psig.  This shift was greater than the 5.8 psig shift
          expected for such temperature variation as specified in
          Rosemount Product Data Sheet PDS 2631/4631 Rev 8/93 and the
          Part 21 letters from Rosemount to Virginia Power on May 27,
          1993 and August 31, 1993.  Although this instrument drift was
          not safety significant for Surry, it was a causal factor in an
          incident in which Unit 2 pressurizer pressure channels had been
          set outside of Technical Specification limits.  Accordingly, it
          was determined that given the variability observed in
          instrument drift and the multiple examples of occurrence, this
          condition could have the potential to be safety significant in
          other similar safety-related applications at other facilities
          dependent on plant specific setpoint margins.  Specific
          applicability with respect to safety systems or licensee
          facilities is not known.

     5.   The date on which the information of such defect or failure to
          comply was obtained.

          April 26, 1995

     6.   In the case of a basic component which contains a defect or
          fails to comply, the number and location of all such components
          in use at, supplied for, or being supplied for one or more
          facilities or activities subject to the regulation in this
          part.

          There are twelve Model 1154SH9 pressure transmitters at Surry:
          three installed in Unit 1 for pressurizer pressure, three
          installed in Unit 2 for pressurizer pressure, and six spares.
          Only the three Unit 2 pressurizer pressure transmitters and one
          spare have exhibited excessive instrument drift and are
          therefore affected by this notification.  There are seven Model
          1154SH9 pressure transmitters at North Anna: three installed in
          Unit 1 for pressurizer pressure, three installed in Unit 2 for
          pressurizer pressure and one spare.  Excessive instrument drift
          has not been observed in the transmitters presently installed.
          (One previous Unit 2 transmitter, which had exhibited excessive
          shift, was replaced earlier with a spare.)

     7.   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.

          As stated above, Virginia Power performed an RCE which resulted
          in the identification of the excessive instrument drift
          concern, the variability of the degree of drift between
          individual transmitters, and the individual transmitter
          applicability (i.e. not all Model 1154SH9 transmitters exhibit
          excessive drift).  Individual instrument channels identified as
          subject to the excessive drift phenomena were evaluated to
          ensure continued operability by establishing that the
          individual transmitter drift was within overall channel
          setpoint margins.

          The NRC was advised of our preliminary findings in a meeting
          with Region II on April 24, 1995.  Copies of our RCE were
          provided to the resident inspectors.  The industry was notified
          of our RCE findings in an INPO Network entry made on June 15,
          1995, which addressed various calibration errors identified
          with the pressurizer pressure protection transmitters.

          We will continue to work with the manufacturer and intend to
          ship one of the transmitters exhibiting excessive drift for
          future investigations of the condition we have observed.

     8.   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.

          Virginia Power advises other licensees to be alert to
          differences in pressure indication between individual Model
          1154SH9 transmitters as well as between functional groupings of
          Model 1154SH9 transmitters and other related but non-Model
          1154SH9 pressure indications.  Either circumstance might
          indicate the presence of excessive shift.  Furthermore for
          temperature sensitive applications, consideration should be
          given in the interim to temperature testing Model 1154SH9
          transmitters prior to use to determine actual temperature
          related shifts.

Should you have any questions or require additional information, please
contact Mr. M. L. Bowling, Manager Nuclear Licensing and Programs, at
(804) 273-2699.

Very truly yours,

R. F. Saunders
Vice President - Nuclear Operations

cc:  U. S. Nuclear Regulatory Commission
     Region II
     101 Marietta Street, N. W.
     Suite 2900
     Atlanta, Georgia 30323

     Mr. M. W. Branch
     NRC Senior Resident Inspector
     Surry Power Station

     Mr. R. D. McWhorter
     NRC Senior Resident Inspector
     North Anna Power Station

     Mr. K. Ewald
     Business Unit Manager
     Rosemount Aerospace Inc.
     1256 Trapp Road
     Eagan, Minnesota 55121

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