TXX-6153, Interim Deficiency Rept CP-85-42 Re Adverse Effect of Rectangular Oversized Preformed Thermolag on Conduit Installations.Initially Reported on 861026.Conduits Evaluated & Corrective Action Initiated.Next Rept by 870428

Interim Deficiency Rept CP-85-42 Re Adverse Effect of Rectangular Oversized Preformed Thermolag on Conduit Installations.Initially Reported on 861026.Conduits Evaluated & Corrective Action Initiated.Next Rept by 870428

ML20212B167
Person / Time
Site:	Comanche Peak
Issue date:	12/12/1986
From:	Counsil W, Keeley G TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	Johnson E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
CP-85-42, TXX-6153, NUDOCS 8612290187
Download: ML20212B167 (2)

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Lcg # TXX-6153

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4 File # 10110 TEXAS UTILITIES GENERATING COMPANY SKYWAY TOWER . 9d NORTH OL8VE NTREET, L.B. 88 . DALLAS. TEXA8 7E301 December 12, 1986 WI.L_LI

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Mr. Eric H. Johnson, Director -J Division of Reactor Safety and Projects U. S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 1000 Arlington, TX 76011

SUBJECT:

COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)

DOCKET NO. 50-445 THERM 0 LAG ON CONDUIT SUPPORT SDAR: CP-85-42 (INTERIM REPORT)

Dear Mr. Johnson:

On October 26, 1986, we notified you (TUGC0 Letter TXX-6049) that the deficiency involving the possible adverse effect of the substitution of rectangular and oversized preformed sections of thermolag on conduit installations is reportable under the provision of 10CFR50.55(e). This is an interim report submitted to status corrective action implemented to date.

An engineering verification was performed, which provided the shape and size of installed thermolag, specific conduit dimensions, support location and configuration. Also, this verification effort provided a complete survey of the original unique IN-FP drawings from the S-0910 document which comprised 329 conduit runs, 141 junction boxes and approximately 1500 conduit supports (including 46 Unistrut supports which are being addressed as part of SDAR CP-85-34).

The IN-FP drawings have been revised to incorporate the engineering verification information, existing design changes and inspection reports.

With the utilization of the revised IN-FP drawings each conduit span had the thermolag weights conservatively calculated and dynamic system analysis performed. All support loads have been established, but final evaluation of the adequacy of the supports cannot be performed until the test data on clamp capacity has been fully evaluated. This specific evaluation is being conducted as a separate issue.

Our present evaluations have established the following conclusions:

1) Nine (9) conduit runs have been identified as overstressed due to overloaded conditions.

o Four (4) of these nine (9) runs are overstressed due to the presence of conduit couplings at the critical section between supports.

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TXX-6153 l e December 12, 1986 i Page 2  ;

o One (1) conduit run will have the existing thermolag removed and replaced with a smaller size.

o Out of these nine (9) conduit runs eight (8) runs will have a total of ten (10) supports added.

2) Fifteen (15) junction box failures were identified.

3) Thirteen (13) conduit support failures were identified by analysis, o The number of conduit support failures (13) may be reduced as a result of refined analysis that is currently being conducted. Any

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found to be unacceptable through refined analysis will be modified. ,

Additional corrective action steps will be established for the remaining identified areas after the Fire Protection analysis of existing conditions to evaluate the adequacy of existing thermolag applications.

We anticipate submitting our next report no later than April 28, 1987.

Very truly yours, Ad#

W. G. Counsil By:

G. S. Keele~ - ' -

g Manager,NuclearL}c[nsing DAR/mlh c - NRC Region IV (0 + 1 copy)

Director, Inspection & Enforcement (15 copies)

U. S. Nuclear Regulatory Commission Washington, D.C. 20555 1

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