ML18030A192

Interim Deficiency Rept Re Use of Improperly Grounded Flexible Conduit on safety-related Circuits,Initially Reported on 801210.Caused by Manufacturer Failure to Remove Paint from Termination Module.Next Rept by Apr 1981

ML18030A192
Person / Time
Site:	Susquehanna
Issue date:	01/14/1981
From:	Curtis N PENNSYLVANIA POWER & LIGHT CO.
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
10CFR-050.55E, 10CFR-50.55E, ER-100450, ER-100508, PLA-613, NUDOCS 8101210362
Download: ML18030A192 (5)

Text

REGULAT~ INFORMATION DISTRIBUTION TEr>> (RIDS)

ACCESSION NBR:8101210362 DOC ~ DATE: 81/Oi/14 NOTARI7ED: NO 00CKET FACIL:g - 8 Susquehanna Steam Electric Station< Unit '1R Pennsylva 05000387 0-.388 Susquehanna Steam Electric Station~ Unit 2< Pennsylva 05000388 A ~ AUTHOR AFFILIATION CURTISR N ~ ency rept re use of improperly grounded flexible conduit on safety-related cir'cuitsEinitiallv reported on 801210 Caused by manufacturer failure to remove

~

paint from termination modules Next rept by April 1981

'I STRI SU TI ON CODE: SOILS COPIES RECEIVED:LTR /ENCL SIZE:

TITLE: Constr uc t i on Deficiency Repor t (10CFR50,55E)

NOTES:Send IEE 3 copies FSAR lt all amends. 05000387 Send ILE 3 copies FSAR R all amends. 05000388 RECIPIENT (.OP I ES RECIPIENT COPIES Io CODE/Nar>>E LTTR EhlCL ID CODE/IYAYiE LTTR ENCL ACTION; A/0 L ICENSNG 04 1 1 YOUf<GBLOODEB 05 1 RUSHBROOKsr>> ~ 06 1 STARKERS 07 1 1 INTERNAL: AD/RCt/IE 17 1 1 AEOD 18 1 1 ASL'BP/J ~ HARD 1 1 D/DIR HUM FAC15 1 1 OIR MDIV OF LIC 1 EDO 8 STAFF 19 l 1 EQUIP QUAL RR1 1 1 1 HYD/GEO BR 22 1 1 IS,E 09 1 1 lIC QUAL BR 12 1 1 iMP A 20 NRC PDR 02 OELO 21 1

1 1

1 .P -- ST REV 13 1

1 1

1 QA BR 14 1 1 REG F II 01 1 1 RUTHERFORDEAs I 1 1 ST ADS, DEV 21 1 1 EXTERNAL: ACRS 16 16 16 LPDR 03 NSIC 08 1 g p ]9Sl TOTAL NUMBER OF COPIES REQUIRED: LTTR ~ ENCL gg

TWO NORTH NINTH STREET, ALLENTOWN, PA. 18101 PHONEr t215) 770-5151 NORMAN W. CURTIS Vice President'-Engineering IL Construction-Nuclear 77D5381 January 14, 1981 Mr. Boyce H. Grier Director, Region I U. S. Nuclear Regulatory Commission 631 Pa k Avenue King of Prussia, PA 19406 SUSQUEHANNA STEAM ELECTRIC STATION INTERIM REPORT OF A DEFICIENCY RELATING TO IMPROPERLY GROUNDED FLEXIBLE CONDUIT ER's 100450/100508 FILE 840-4 PLA-613

Dear Mr. Grier:

This letter serves to confirm information provided by telephone to NRC Inspector, Mr. J. Mattia, by Mr. A. R. Sabol of PP&L on December 10, 1980.

During that conversations Mr. Mattia was advised that the subject condition was under evaluation for reportability under the provisions of 10CFR50.55(e).

The deficiency involves the use of improperly grounded flexible conduit in various safety related circuits as reported to the NRC by General Electric under the provisions of 10CFR 21 on December 8, 1980 (Letter No.

MFN212-80) . PPaL has evaluated the condition and determined that it is reportable under 10CFR50.55(e). A complete description of the condition along-with its safety implications and corrective action planned is attached to this letter.

Since the details of this report provide information relevant to the reporting requirements of 10CFR 21, this. correspondence is considered to also discharge any formal responsibility PPaL may have for reporting in compliance thereto.

We expect to provide a final report prior to April, 1981.

PENNSYLVANIA POWER IL LIGHT COMPANY 8 1 02 2 2 0 '3 llt7t

Mr. Boyce H-. Griex January 14, 1981 Very truly yours, N. W. 'Curtis Vice President-Engineering 6 Construction-Nucleax'LW:sab Attachment cc: Mr. Victor Stello (15)

Director-Office of Enspection a Enforcement U. S. Nuclear Regulatory Commission Washington, D.C. 20555 mcsghgme Office of Management Information a Program Control U. S. Nuclear Regulatory Commission Washington, D.C. 20555 Mr. Robert M. Gallo U. S. Nuclear Regulatory Commission P.'O. Box 52 Shickshinny, PA 18655

INTERIM REPORT

~sub 'ec0: Improperly Grounded Flexible Conduit on Safety-Related Fail Safe Circi Metallic flexible conduit is utilized to enclose electrical conductors in various fail-safe (deenergize to perform the 'safety function) safety related circuits. These fail-safe ci.rcuits, are part of the Reactor .

Protection System (RPS), Nuclear Steam Supply Shut-Off'System (NSSS) and Neutron Monitoring System (NMS) logics. The'ail-safe design requires that

.the flexible conduit provide a low resistance path to ground .to prevent external voltage sources, that could occur from certain short circuits, from defeating (deenergizing to operate) fail-safe mode of these safety related circuits. The positive ground path assures that the upstream protective devices will sense and interrupt a short circuit, thereby eliminating the possibility of an external voltage source defeating the safety function.

Flexible conduit i:s utilized for fail-safe circuits within the GE-supplied Power Generation Control Complex (PGCC). Typically the flexible conduit is routed through the PGCC floor sections from the termination cabinets to panels or from panel to panel.

The defect being reported is the lack of positive metallic grounding for the flexible conduit either at the terminati.on cabinet or at the panel. In a typical term@nation cabinet installation; the conduit is attached with a locking ring to a termination module. This is an acceptable ground connecti.on; however, the termination module is ultimately mounted on a painted (high electrical resistance) surface. During manufacturing, there was no procedure to assure paint was removed prior to mounting the termination module. Hence, a positive ground path was not provided.

GE has reported this defect to the NRC under 10 CFR, Part 21.

Anal sis of Safet Im lications The design basis, for safety-related fail-safe circuits of the RPS, NSSS and NMS systems requires protection against the possibility of loss of protective functions from external voltage sources. Installation of these circuits in 'positively grounded metallic conduit is required to meet this design basis.'.

Engineering considers the omission of a positive ground on the GE supplied flexible metal'lic conduit to be a significant deficien'cy in design and construction of the PGCC such that if it were to have remained uncorrected, could have adversely affected the safety of operation of the plant. Therefore, the lack of grounding on flexible metallic conduit containing safety-related fail-safe circuits within the PGCC is considered reportable under 10 CFR 5e.55 (e).

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Corrective Action:

GE wi;11 issue instructions. to field investigate installations of fail-safe circuits in flexible conduit ~for adequate grounding.

is. found to will be Where'he grounding be unacceptable, positive grounding installed.

I Bechtel has been instructed to review'nstallations of safety-related fail-safe circuits within. their design scope to assure that positive raceway grounding has been applied.

A final report identifying the total scope of the problem and corrective actions will be provided by March 31, 1981.

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