TXX-6046, Interim Deficiency Rept CP-85-19 Re Conduit Support Spans. Initially Reported on 850515.Field Verifications & Engineering Evaluations Continuing for Unit 1.Design Verification Conducted for Unit 2.Next Rept by 870310

Interim Deficiency Rept CP-85-19 Re Conduit Support Spans. Initially Reported on 850515.Field Verifications & Engineering Evaluations Continuing for Unit 1.Design Verification Conducted for Unit 2.Next Rept by 870310

ML20215L969
Person / Time
Site:	Comanche Peak
Issue date:	10/21/1986
From:	Counsil W, Keeley G TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	Johnson E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
CP-85-19, TXX-6046, NUDOCS 8610290404
Download: ML20215L969 (2)

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Log # TXX-6046 .

! File # 10110 I l 903.11 l

! TEXAS UTILITIES GENERATING COMPANY l

l October 21, 1986 i

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l OCT 211986 . ,!

Mr. Eric H. Johnson, Director Division of Reactor Safety and Projects

[ L  ; l ,u U. S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 1000

Arlington, TX 76012 l

SUBJECT:

COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)

DOCKET NOS. 50-445 AND 50-446 CONDUIT SUPPORT SPANS SDAR: CP-85-19 (INTERIM REPORT) l

Dear Mr. Johnson:

On May 15, 1985, we verbally notified your Mr. D. Hunnicutt of a deficiency regarding the use of a nonrepresentative sample in determining generic values for typical conduit span calculations. Our most recent interim report was logged TXX-4804, dated May 16, 1986. We are reporting this issue under the provisions of 10CFR50.55(e) and the required information follows.

DESCRIPTION l

The seismic conduits and conduit supports at CPSES are segregated into Trains A, B and C. Conduit supports on Trains A and B are safety related. Train C conduit supports are considered to be non-safety related with the following exceptions:

- Unit 2, Train C conduits which are larger than 2 inches in diameter and their conduit supports are seismically designed with the same requirements as Trains A and B.

a

• g - Unit 1, supports on Train C conduits which are over 2 inches in diameter 5'ga. are grouped into three categories: 1) seismically designed, 2) seismically Og restrained with aircraft cables, and 3) non-seismically designed. This g, issue addresses the conduits which are seismically supported or restrained.

$2 Seismic conduit and support design is governed by two documents: the S-0910 g design package for Unit 1 and Common areas, and the S2-0910 design package for p Unit 2. These documents describe various types of " engineered" and " generic" y supports along with the allowable conduit spans. Supports deviating from

• g generic support criteria are identified as either " Modified" or " Individually

$a.cn Engineered" (IN) supports.

External Design Reviews identified a specific concern questioning the yield stress tests used to justify the conduit span calculations for Units 1 and 2.

This issue is addressed as CPRT Program Plan Item DSAP VIII. A comprehensive reverification plan has been implemented in order to resolve these concerns.

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TXX-6046 l October 21, 1986 l Page 2 of 2 i Results of this verification to date indicate that a number of supports in Unit I have reduced capacities for certain elevations and buildings.

Moreover, certain extreme span configurations may cause overstressing of the conduit and overloading of supports. Evaluations of conduit support spans in Unit '2 are in progress.

SAFETY IMPLICATIONS Failure of seismic category conduits and conduit supports to meet the design criteria could result in an inability of associated safety related systems to perform as required for safe operation and shutdown.

CORRECTIVE ACTION For Unit 1, field verifications and subsequent engineering evaluations are continuing. Formulation of corrective actions resulting from this evaluation will be complete by February 17, 1987.

For Unit 2, a complete design verification of the S2-2910 design package is being conducted. This design verification and the preparation and 4

verification of the isometric drawing packages is contingent upon Project schedules which are currently being redefined.

We anticipate submitting our next report by March 10, 1987.

Very truly yours, h 14 Y W. G. Co i l ,,

By: ., m

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G. 'S. Keeleh /-

Manager, Nuclear icensing JCH/gj c - NRC Region IV (0 + 1 copy)

Director, Inspection & Enforcements (15 copies)

U. S. Nuclear Regulatory Commission Washington, D.C. 20555 4

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