ML20045B518

LER 93-007-00:on 930512,protective Devices Not Analyzed to Function During Environ Excursions Due to Unknown Cause Which Is Under Review.Operability Determination Was performed.W/930611 Ltr

ML20045B518
Person / Time
Site:	Seabrook
Issue date:	06/11/1993
From:	Feigenbaum T, Peschel J NORTH ATLANTIC ENERGY SERVICE CORP. (NAESCO)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-93-007, LER-93-7, NYN-93085, NUDOCS 9306180035
Download: ML20045B518 (5)

Text

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                                             =                                               Telephone (603)474-9521 -

( Facsimile (603)474-2987 Energy Service Corporation Ted c: Feigenbe.um i Senior Vice President and  : Chief Nuclear Officer  ? NYN- 93085  ; June 11,1993 United States Nuclear Regulatory Commission  : Washington, D.C. 20555 ' I Attention: Document Control Desk [

Reference:

(a) Facility Operating License No. NPF-86, Docket No. 50-443  ;

Subject:

Licensee Event Report (LER) 93-07-00: ' Protective Devices Not Analyzed to Fuaction During Environmental Excursions' Gentlemen: Enclosed is Licensec Event Report (LER) No. 93-07-00 for Seabrook Station. This submittal documents an event which occurred on May 12,1993. This event is being reported pursuant to 10CFR50.73(a)(2)(ii). This event was previously reported by North Atlantic on , May 12,1993, pursuant to 10CFR50.72(b)(2)(ii).  ; Should you require further information regarding this matter, please contact Mr. James M. Peschel, Regulatory Compliance Manager at (603) 474-9521 1 3772. Very ruly yours, V AJ Ted L. Fei nbaum ., TCF:MDO/ tad s ,

Enclosures:

NRC Forms 366/366A s

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                     - United States Nuclear Regulatory Commission                      June 11,1993       !

Attention: Document Control Desk Page two cc: - Mr. Thomas T. Martin Regional Administrator l 1! United States Nuclear Regulatory Commission Region 1 475 Allendale Road i King of Prussia, PA 19406 , Mr. Albert W. De Agazio, Sr. Project Manager i

            /                       Project Directorate 'I-4.                                              {'

Division of Reactor Projects U.S. Nuclear Regulatory Commission ' ~'

      ;                             Washington,.DC 20555                                                    ;
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          ,                         Mr. Noel Dudley                                                         ;

NRC Seniar Resident Inspector  ! P.O. Box 1149 ,

                                ,; Seabrook, NH 03874 r                                ,..                                                                       :

INPO ~! Records Center 700 Galleria Parkway -{ Atlanta, GA 30339-5957 -l; a I 9 I i i 1

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NRC FORM 356 U.S. NUCLEAR REGULATORY CDP 9tlSSI0ii APPROVD) B7 OMB NO. 3150-0104 ' (5-92) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO LICENSEE EVENT REPORT (LER) THE INFORMATION AND RECORDS MANAGEMENT BRANCH (MNDB 7714), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503. [ (See reverse for required numtier of digits / characters for each block) FACILITY NAME (1) DOCKETNUMBER(2) PAGE(3) Seabrook Station 05000443 1 OF 3 TITLE (4) Protective Devices Not Analyzed to Function During Environmental Excursions EVENT DATE (5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED (8) REVISION MONTH DAY YEAR YEAR MONTH DAY YEAR HUMBER NUMBLR 05000 FACILITY NAME DOCKET NUMBER 05 12 93 93 -- 07 -- 00 06 11 93 05000 OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR 6: (Check one or nore) (11) 1 MODE (9) 20.402(b) 20.405(c) 50.73(a)(2)(iv) 73.71(b) POWER 20.405(a)(1)(1) 50.36(c)(1) 50.73(a)(2)(v) 73.71(c) 100 LEVEL (10) 20.405(a)(1)(11) 50.36(c)(2) 50.73(a)(2)(v11) OTHER 20.405(a)(1)(iii) 50.73(a)(2)(i) 50.73(a)(2)(viii)(A) (Specify in ow 20.405(a)(1)(iv) X 50.73(a)(2)(ii) 50.73(a)(2)(viii)(B) fjtrac 20.405(a)(1)(v) l 50.73(a)(2)(iii) 50.73(a)(2)(x) NRC Form 366A) LICENSEE CONTACT FOR THIS LER (12) NAME ILLLPHONE NUMBER (include Area Code) Mr. James M. Peschel, Regulatory Compliance Mngr. (603)474-9521 ext. 3772 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13) CAUSE SYSTEM COMPONENT MANUFACTURER E CAUSE SYSTEM COMPONENT MANUFACTURER R 0 E 3 SUPPLEMENTAL REPORT EXPECTED (14) EXPECTED MONTH DAY YEAR Y SUDMISSION X (ES If yes, complete EXPECTED SUBMISSION DATE). NO 08 27 93 DATE(15) ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) (16) On May 12,1993, North Atlantic Energy Senice Corporation (North Atlantic) determined that some items containing circuit protective devices were not analyzed to function during emironmental excursions to which they may be subjected. The subject items containing circuit protective devices consist of non-Class 1E items located in harsh emironments, or mild environments which could experience an emironmental excursion; and Class 1E items located in mild emironment areas which could experience emironmental excursions. This event was previously reported on May 12,1993, pursuant to 10CFR50.72(b)(ii) as a condition outside the design basis of the plant. North Atlantic performed an evaluation of the items containing circuit protective devices. This evaluation determined that the devices would be capable of performing their circuit protective function if they were subjected to an emironmental excursion. The ability of these devices to perform their circuit protective function ensures that Class IE cable in the same cable tray would not be degraded by a fault occurring on a Class IE or non-Class IE load. The root cause of this event is under review and will be provided to the NRC in a supplemental report, immediate corrective action w .s performance of an Operability Determwation which verified that Class IE cables, which share the same cable tray as non-Class IE cable, would continue to perform their intended safety function. In addition, North Atlantic replaced the normally energized circuit protective devices located in containment with like items which had been tested to verify their high current tripping capability.

LC f ORM 366A U.S. NUCLEAR REGULATORY COP 9tISSION APPROVED BY OMB NO. 3150-0104 , (5-92) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO LICENSEE EVENT REPORT (LER) THE INFORMATION AND RECORDS MANAGEMENT BRANCH TEXT CONTINUATION (MNBB M 4), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555-0001, AND TO THE PAPERWDRK REDUCTION PROJECT {3I50-0104), OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503. FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6? PAGE (3) YEAR SEQUENTIAL REVISION Seabrook Station " 05000443 93 2 OF 3

                                                                                            -- 007 -- 0 TEKT (1f more space is required, use additional copies of NRC fom 36bA) (11)

On May 12,1993 North Atlantic Energy Service Corporation (North Atlantic) determined that some items containing electrical protective devices were located in emironments for which they were not analyzed. This event was reported pursuant to 10CFR50.72(b)(ii) as a condition outside the design basis of the plant. The non-Class 1E electrical circuits at Seabrook Station aa., designated as " associated circuits". Appendix 8A of the Updated Final Safety Analysis Report (UFSAR) defines " associated circuits" as follows:

            "Non-Class IE circuits that share power supplies, enclosures, or raceways with Class IE circuits or are not physically separated from class 1E circuits by acceptable separation distance or barriers" The cable routing design at Seabrook Station employs four (4) separation groups. All non-Class IE electrical circuits are associated with and routed in one of the four (4) separation groups. UFSAR Section 83.1.4 " Independence of Re:iundant Systems" describes this separation design and provides an analysis which " examines the design features and modes of failure of associated circuits of each separation group to determine any interaction and challenges with other separation groups. The overall objective is to assure that the ability to achieve a safe plant shutdown under design basis event (DBE) conditions is not compromised".

Non-Class IE electrical circuit protective devices are provided in the Seabrook Station design to remove power from the circuit if the non-Class 1E load were to fail during a design-basis event. Removal of power from the non-Class 1E electrical circuits ensures that the Class 1E electrical circuits which are routed in the same cable trays are not degraded and are able to perform their specified safety function. North Atlantic has determined that some items containing circuit protective devices were not analyzed to function during emironmental excursions to which they could be subjected. The devices consist of non-Class IE items located in harsh emironments, or mild emironments which could experience an emironmental excursion; and Class 1E items located in mild emironments which could experience emironmental excursions. North Atlantic evaluated the subject items containing circuit protective devices and determined that the protective devices, located in areas which experience environmental excarsions, would continue to perform their circuit protective function in those areas if called upon to do so. In addition, North Atlantic replaced the normally energized circuit protective devices located in containment with like items which had been tested to verify their high current tripping capability. North Atlantic has also identified other issues pertaining to the procurement and inspection of associated circuits as well as i the interpretation of UFSAR commitments. These issues are currently being evaluated and will be discussed in a supplemental report. Safety Consecuences There were no adverse safety consequences as a result of this event. An evaluation performed by North Atlantic determined that the subject items containing circuit protective devices would continue to perform their circuit protective function in the event they were exposed to an emironmental excursion. This assures that an electrical fault occurring on Class IE or non-Class IE equipment would not degrade safety related equipment. l NRC FORM 356A (5-92) i i I i

NRC FORM 366A U.S. NUCLEAR REGULATORY C0retISSION APPROVED BY OMB NO. 3150-0104 (5-92) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH

   ** .                                                                          THIS INFORMATION COLLECTION REQUEST: 50.0 HRS.

FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO LICENSEE EVENT REPORT (LER) THE INFORMATION AND RECORDS MANAGEMENT BRANCH TEXT CONTINUATION (MNBB 7714), U.S. NUCLEAR REGUL ATORY COMMISSION, WASHINGTON. DC 20555-0001, AND TO THE PAPERWORK REDUCTION PROJECT ( 3150-0104) . OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503. IACitlTY NAME (1) DOCKEl NUMBLR (2) LLR NUMBER (6? PAGE (3)

                                                                                            $EQUENTIAL     REVISION YEAR Seabrook Station                                                                    "             "      "

05000443 93 0 3 OF 3

                                                                                          -- 07       --

TEKt (if more space is required, use additional copies of NRC Fonn 366A) (17) Root Cause The root cause of this event is currently under investigation and will be provided to the NRC in a supplemental report. North Atlantic expects to submit this report by August 27,1993. Corrective Actions North Atlantic has taken or will take the corrective actions listed below. This listing may be revised when the LER supplement is completed.

1. The UFSAR will be revised to clearly state the requirements for procurement and inspection of associated circuit protective devices.

2. A design change will be developed to resolve concerns about items containing circuit protective devices located in harsh emironments.

3. Training on associated circuits will be provided for appropriate personnel.

4. An Independent Review Team has been assigned to perform a comprehensive evaluation of associated circuits at Seabrook Station. The evaluation will encompass the extent of clarity of licensing documents, the translation of licensing commitments into functional area programmatic and procedural controls, and the root cause(s) of programmatic or procedural control deficiencies, if any.

Previous Occurrences This is the first event reported by North Atlantic invohing associated circuits. North Atlantic will report any previous occurrences once a root cause determination is completed. At the time of the event the plant was in Mode 1 at 100% power. i hRC 10RM .ibbA (5-92))}}