ML18102A370

Part 21 Rept Re Installation of NUS Model OCA 801 Signal Isolator Modules & Model Mth 801 Signal Summator Modules. Replacement Modules Including Spares for Plant,Unit 2 Have Been Inspected by Vendor & Repaired

ML18102A370
Person / Time
Site:	Salem
Issue date:	09/06/1996
From:	Eric Simpson Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
REF-PT21-96 LR-N96274, NUDOCS 9609170010
Download: ML18102A370 (5)

Text

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. Electric and Gas Company E. C. Simpson Public Service Electric and Gas Company P.O. Box 236, Hancocks Bridge, NJ 08038 609-339-1700 Senior Vice President - Nuclear Engineering LR-N96274 SE~ 06 1996 United States Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 Gentlemen:

10 CFR 21 NOTIFICATION, NUS SUMMATOR AND ISOLATOR MODULES SALEM GENERATING STATION UNITS 1 AND 2 FACILITY OPERATING LICENSE NO. DPR-70 AND DPR-75 DOCKET NOS. 50-272 AND 50-311 Pursuant to the notification requirements of 10 CFR 21.21(d) (3) (ii), Public Service Electric and Gas Company (PSE&G) is providing the attached written notification on the identification of a defect in NUS summator and isolator logic modules. PSE&G identified this deviation on June 25, 1996 and made initial notification to the NRC Operations Center as required by 10 CFR 21.21(d) (3) (i) on August 8, 1996.

Should you have any questions, please contact us.

Sincerely, Attachment (1)

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~ Recycled Paper

Document Control Desk LR-N96274 C Mr. H. J. Miller, Administrator - Region I U. s. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 Mr. L. Olshan, Licensing Project Manager - Salem

u. s. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Mail Stop 14E21 Rockville, MD 20852 Mr. C. Marschall (X24)

USNRC Senior Resident Inspector Mr. K. Tosch, Manager IV Bureau of Nuclear Engineering 33 Arctic Parkway CN 415 Trenton, NJ 08625 NUS P.O. Box 50736 Idaho Falls, ID 83405

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, Units 1 and

2. The basic components are Reactor Control and Protection System signal isolator and signal summator modules:

Isolator module Model No. OCA801 Summator module Model 'No. MTH801 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 MTH801 Signal Summator Modules are being installed as replacements for modules in the Hagan 7100 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. The replacement summator and isolator modules for Salem Unit 2

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• Attachment 1 were then inspected. Of 220 modules inspected, fifteen were found to have solder workmanship deficiencies (i.e.,

joints with no solder or with insufficient or cold solder). 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 reactor protection system is designed to assure that the system can perform its required functions in the event of a design basis earthquake. The missing and defective solder joints could affect the modules' ability to function during a design basis earthquake. It is not practical to determine the exact failure modes introduced by these defects for each plant application. However, due to the interchangeability of the modules, the defects 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 25, 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.

219 replacement modules are being installed or kept as spares for Salem Unit 2. 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.

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

PSE&G requested the vendor to perform a root cause analysis of the deficiencies. NUS provided a report of their evaluation to PSE&G on September 3, 1996. NUS concluded that the soldering workmanship deficiencies were due primarily to failure to perform self-verification by assembly personnel and inadequate supervisory monitoring of module assembly. NUS stated that they had taken action to prevent recurrence and had communicated the results of their inspection to affected personnel.

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.