ML20067A638

Interim Deficiency Rept CP-91-01 Re Potential for Electrical Penetration Assembly Overpressurization.Initially Reported on 910103.Review & Determination of Corrective Actions Will Be Completed by 910731

ML20067A638
Person / Time
Site:	Comanche Peak
Issue date:	02/01/1991
From:	William Cahill, Woodlan D TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
CP-91-01, CP-91-1, TXX-91056, NUDOCS 9102070329
Download: ML20067A638 (2)

Text

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Log # TXX 91056

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Fi1e # 10110

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R50,55(e)

Williara J Cahill, Jr.

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February 1, 1991 U.ES. Nuclear Regulatory Cuwi.,i 9n i

Attn

. Document Control Desk Washington. 0.C.

20555

.5UBJECT:

COMANCHE PEAK STEAM ELEC1hlC STATION (CPSES)

DOCKET NQ, 50-446 POTENTIAL-FOR ELECTRICAL PENETRATION

ASSEMBLIES 071.RPRESSURIZAT10H SDAR

CP-91 01 (INTERIM-REPORT)

Gentlemen:

On:Jancary 3, 1991, we orally notified the NRC Region IV office of o deficieacy involving the potential for electrical penetration assembly evernrassurization.

This deficiency has been evaluated and determined to be reportable pursuant to 10CFR50,55(e). This condition was reported for Unit 1 1

via LER-90 039,-

' Description Of The Deficiency CPSES. Electrical ' Penetration Assemblies (EPAs). supplied.by Conax, consist of electric-conductors,sconductor-seals, nodule--seals, and aperture seals =that allow.for the passage of electric.-conductors through a single aperture in the nuclear: containment structure, while providing a pressure barrier between'the 4

n

'inside and outside of-the containment structure.

The EPAs are designed.in conformance with Regulatory Guide.1,63 and IEEE 317-1976.

Each EPA has double aperture seals with the-inboari to G

Containment seals providing the Containment pressure boundary, Each EPA has porting interconnecting-the volume between three sets of double seals'that allows monitoring and or testing of the seal for integrity.

Except for the Airlock.EPAs, Containment EPAs are connecttd to a 4 dicated Lnon-safety-related Nitrogen Pressurization-System.

The Nitrogen 1'

.Pressurizati'on. System wa's originally provided i'n accorda'nce with Bunker Ramo

recommendations to facilitate the maintenance of the penetrations-alth a H2 blanket to prevent moisture ingress or condensation which could-eventually result in equipment degradation.

Conax has indicated that the:

Nitrogen Pressurization System is not required during normal or accident Leondition's ~and is therefore:not required for. the Containtient EPAs to perform their safety' function.

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9102070329 910201 PDR ADOCK 05000446

,vu north Olive Street 1,B. 81 ' Dallas, Texas 75201

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__TXX-91056 Page 2 of 2 As a result of_the condition discovered in Unit I described in LER-90 039, Nitrogen Pressurization System non compliance with FSAR design basis, an applicability review was done for Unit '2 and determined that the Nitrogen Pressurization System design is similar to that of Unit 1.

On December 3, 1990, a TUE form was generated to document the potential for

-overpressurization of-the EPAs with a resulting potential for loss of Containment integr_ity for Unit 2.

lafety ImD11 cations Primary containment integrity ensures that the release of radioactive materials from the containment atmosphere will be restricted to those leakage-paths'and associated leak rates assumed in the safety oaalysis.

This restriction, in conjunction with the leakage rate limitation, will limit the exclusion area bourdary radiation _ doses to within the dose guideline values of 10CFR100 during accident conditions, llad-this deficiency remained uncorrected, the potential failure of EPAs existed due toioverpressurization from the Nitrogen Pressurization System.

Failure of the EPAs could have resulted in potential leakage paths and associated leak rates in excess of those assumed in the safety analyses. As a result, the potential for exceeding 10CFR100 limits could'have existed.

The described-condition represents a deficiency in final design es releasea for: construction'and is-considered reportable under 10CFR50.55(e).-

Corrective-ActioJ1 j

Due tn[the construction status of Unit 2. no immediate corrective actions were required.

Unit-2 Engineering is.losely monitoring the corrective actions of Unit 11._ Upon completion of-design validation of the EPA Hitrogen Pressurization System and related-corrective actions by Unit 1 _ Unit 2 Engtneering will review the results and determine' specific corrective actions i

required-'for Unit 2..

We anticipate this action to_be complete by F

July 31,11990 Sincerely, William J. Cahill. Jr.

By:

D. R. Woodlan Docket Licensing Manager

'JLR/bm c

_Mr__R.

D. Hartin. Region IV Resident inspectors. CPSES.(3)

Mr. M. Fields. NRR i

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