Part 21 Report - 1996-741

 
 
ACCESSION #: 9611200167

                     Initial 10 CFR 21 Notification
                    NUS Summator and Isolator Modules

I.   NAME AND ADDRESS OF THE INDIVIDUAL(S) INFORMING THE COMMISSION.

     NAME:     E. C. Simpson
               Senior Vice President - Nuclear Engineering

     ADDRESS:  Public Service Electric and Gas Company
               P.O. Box 236
               Hancock's Bridge, NJ 08038

II.  IDENTIFICATION OF THE FACILITY, ACTIVITY OR COMPONENT WHICH FAILS
TO
     COMPLY OR CONTAINS A DEFECT.

     The facility is the Salem Generating Station, Unit 2.  The basic
     components are Reactor Control and Protection System signal isolator
     and signal summator modules.

III. IDENTIFICATION OF THE FIRM SUPPLYING THE BASIC COMPONENT WHICH
FAILS
     TO COMPLY OR CONTAINS A DEFECT.

     The modules were manufactured by:

     NUS
     P.O. Box 50736
     Idaho Falls, ID 83405

IV.  NATURE OF THE DEFECT OR FAILURE TO COMPLY AND THE SAFETY HAZARD
     WHICH IS CREATED OR COULD BE CREATED.

     NUS Model OCA801 signal isolator modules and Model MTH 801 Signal
     Summator Modules are being installed as replacements for modules in
     the Reactor Control and Protection System to provide improved
     reliability.  During bench testing, an electrical connection with no
     solder was observed on a replacement summator module.  All
     replacement summator and isolator modules for Salem Unit 2 were then
     inspected.  Ten (of 222) modules were found to have unsoldered
     electrical connections.  Another seven modules were found to have
     insufficient solder on at least one connection.  Some of the
     defective connections were covered by heat shrink insulation.

     The isolator modules function to provide electrical separation
     between the Reactor Protection System (Class 1E) and the Process
     Control System (non-Class 1E) portions of the Reactor Control and
     Protection (RCP) instrument loops.  The summator modules are used to
     algebraically combine analog signals, either adding or subtracting
     inputs in combination with module gain and bias.  The summators
     accept up to four inputs and provide one summed and isolated output.

     The reactor protection system is designed to assure that the system
     can perform its required functions in the event of a design basis
     earthquake. The defect could affect the modules' ability to function
     during a design basis earthquake.  It could result in a loss of
     redundancy sufficient to constitute a major degradation of essential
     safety related equipment.

V.   THE DATE ON WHICH THE INFORMATION OF SUCH DEFECT OR FAILURE TO
     COMPLY WAS OBTAINED.

     The information was obtained on June 28, 1996.

VI.  IN THE CASE OF A BASIC COMPONENT WHICH CONTAINS A DEFECT OR FAILS
TO
     COMPLY, IDENTIFY THE NUMBER AND LOCATION OF ALL SUCH COMPONENTS
IN
     USE AT OR SUPPLIED FOR PSE&G FACILITIES SUBJECT TO THE REGULATIONS
     OF 10 CFR 21.

     222 replacement modules are being installed in the Salem Unit 2
     Reactor Control and Protection System.  The replacement modules for
     Salem Unit 1 have been returned to the vendor.

VII. THE CORRECTIVE ACTION WHICH HAS BEEN, IS BEING, OR WILL BE TAKEN;
     THE NAME OF THE RESPONSIBLE INDIVIDUAL OR ORGANIZATION; AND THE
     LENGTH OF TIME THAT HAS BEEN OR WILL BE TAKEN TO COMPLETE THE
     ACTION.

     All replacement modules for Salem Unit 2 have been inspected by the
     vendor and repaired.  All replacement modules for Salem Unit 1 have
     been returned to the vendor for inspection and repair.

     PSE&G is investigating the cause of the defect with the vendor.
     Results will be provided when the investigation is complete.

VIII. ANY ADVICE RELATED TO THE DEFECT OR FAILURE TO COMPLY THAT HAS
      BEEN, IS BEING, OR WILL BE GIVEN TO PURCHASERS OR LICENSEES.

     None.

                             NRC DATA SHEET
                              (Page 1 of 2)

NOTIFICATION TIME   FACILITY OR ORGANIZATION  UNIT     CALLER'S NAME

TELEPHONE NUMBER (FOR CALL BACK)

EVENT TIME & ZONE  EVENT DATE           EVENT CLASSIFICATION (Check One)

                              GENERAL EMERGENCY   * 1HR 10CFR50.72(b)(1)
                                                       (     )
POWER/MODE     POWER/MODE
BEFORE         AFTER          SITE AREA EMERGENCY * 4HR 10CFR50.72(b)(2)
                                                       (     )

                              ALERT                 1HR SECURITY/
                                                    SAFEGUARDS

                              UNUSUAL EVENT         TRANSPORTATION EVENT

                                                    OTHER:

                              *    FOR NON-EMERGENCIES PROVIDE THE
                                   SPECIFIC SUBPART NUMBER OF THE
                                   10CFR50.72 REPORTING REQUIREMENT FROM
                                   THE ECG INITIATING CONDITION
                                   STATEMENT.

                            EVENT DESCRIPTION

Include   In accordance with 10 CFR 21.21(d)(3)(i), the attached initial
          notification is provided on the NUS Summator and isolator
          modules.  NUS Model OCA801 signal isolator modules and Model
          MTH 801 Signal Summator Modules are being installed as
          replacements for modules in the Reactor Control and Protection
          System to provide improved reliability.  During bench testing,
          an electrical connection with no solder was observed on a
          replacement summator module.  All replacement summator and
          isolator modules for Salem Unit 2 were then inspected.  Ten (of
          222) modules were found to have unsoldered electrical
          connections.  Another seven modules were found to have
          insufficient solder on at least one connection.  Some of the
          defective connections were covered by heat shrink insulation.

          The isolator modules function to provide electrical separation
          between the Reactor Protection System (Class 1E) and the
          Process Control System (non-Class 1E) portions of the Reactor
          Control and Protection (RCP) instrument loops.  The summator
          modules are used to algebraically combine analog signals,
          either adding or subtracting inputs in combination with module
          gain and bias.  The summators accept up to four inputs and
          provide one summed and isolated output.

          The reactor protection system is designed to assure that the
          system can perform its required functions in the event of a
          design basis earthquake.  The defect could affect the modules'
          ability to function during a design basis earthquake.  It could
          result in a loss of redundancy sufficient to constitute a major
          degradation of essential safety related equipment.  All
          replacement modules for Salem Unit 2 have been inspected by the
          vendor and repaired.  All replacement modules for Salem Unit 1
          have been returned to the vendor for inspection and repair.
          PSE&G is investigating the cause of the defect with the vendor.
          Results will be provided when the investigation is completed.

NOTIFICATIONS  YES  NO  WILL BE    ANYTHING UNUSUAL    YES            NO
                                   OR NOT UNDERSTOOD?  (Explain above)
NRC RESIDENT

STATE(s) (NJ)
         (DEL)                     DID ALL SYSTEMS     YES            NO
                                   FUNCTION AS                   (Explain
                                   REQUIRED?                     above)
LOCAL (LACT)

OTHER GOV.                         MODE OF     ESTIMATE FOR    ADDITIONAL
AGENCIES                           OPERATION   RESTART DATE:   INFO ON
                                   UNTIL                       PAGE 2?
MEDIA/PRESS                        CORRECTED:
RELEASE

ADDITIONAL INFORMATION FOR TELECOPY E

ECG Section    Initiating Condition     APPROVED FOR TRANSMITTAL:
                                                                 SNSS

SGS                                                                Rev. 2

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