ML20091P621

Final Deficiency Rept CP-91-001 Re Potential for Electrical Penetration Assembly Overpressurization.Initially Reported on 910201.Nitrogen Penetration Sys Will Be Modified to Disconnect Bottles,Pressure Switches & Associated Alarms

ML20091P621
Person / Time
Site:	Comanche Peak
Issue date:	01/31/1992
From:	William Cahill, Walker R TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
CP-91-001, CP-91-1, TXX-92029, NUDOCS 9202030225
Download: ML20091P621 (1)

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Log # T"X-92029 b J File # 10110 C

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C" 908.3 Ref. # 10CFR50.55(e)

TUELECTRIC Williana J.Cahnt Jr.

Groep Ywe fruidew U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555

SUBJECT:

COMANCHE PEAK STEAM ELECTRIC STATION (CPSES) UNIT 2 DOCKET NO. 50 446 POTENTIAL FOR ELECTRIC PENETRATION ASSEMBLIES OVERPRESSURIZATION SDAR CP-91-001 (FINAL REPORI')

REF: 1. TU Electric letter logged TXX 91056 from William J. Cahill, Jr.

to V. S. Nuclear Regulatory Commission dated February 1,1991.

2. TV Electric letter logged TXX-91258 from William J. Cahill, Jr.

to U. S. Nuclear Regulatory Commission dated July 24, 1991.

Gentlemen:

TU Electric notified the NRC staff, via the above referenced letters of a reportable deficiency involving the potential for electrical penetration assembly (EPA) overpressurization. The purpose of this final report is to provide the corrective action to be performed which alleviates the potential for EPA overpressurization for Unit 2.

As originally designed, a Nitrogen Pressurization (N ) System 2 and leak detection system was provided specifically for Bunker Ramo penetration assemblies. Failure of the non-safety pressure control valve could have overpressurized the EPA's causing a loss of containment integrity.

TU Electric has revised the appropriate Design Basis Documents stating that the Nitrogen Pressurization System or pressure monitoring is not required (i.e.,

the Conax feedthrough assemblies installed in Unit 2 do not require this system to perform their safety function). The N2 system will be modified to disconnect the N2 bottles in place, pressure switches and associated alarms.

This will remove the source of high pressure. Associated corrective actions will'be completed prior to fuel load for Unit 2. >

/[

William J. Cahill, Jr.

9202030225 920131 PDR B: 1 -

S ADOCK 05000446 Roger J. Waher PDR MLosger of Nuclear Licensing JLR/gj c - Mr. R. D. Martin. Region-IV d Resident-Inspectors. CPSES (2)

Hr. H. B. Fields. NRR }r a ,i h

400 N, ouve street LB. 81 Dauas, Texas 75201 l

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