TXX-6048, Interim Deficiency Rept CP-85-35 Re Design & Const Activities of Cable Tray Hanger Program.Initially Reported on 850906.Verification Program implemented.As-built Drawings for Supports Developed.Next Rept Expected by 870130

Interim Deficiency Rept CP-85-35 Re Design & Const Activities of Cable Tray Hanger Program.Initially Reported on 850906.Verification Program implemented.As-built Drawings for Supports Developed.Next Rept Expected by 870130

ML20215L023
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), NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
CP-85-35, TXX-6048, NUDOCS 8610280431
Download: ML20215L023 (3)

Text

DALLAS-SLIC TEL No. 214 979 8700 Oct 21,86 17:05 P.04 e

Log # TXX-6048 File # 10110 1 903.9 TEXAS UTILITIES GENERATING COMPANY SEYWAY TOWBa . 400 NomTlf 01JVB 87333t7. La. e 3 e ThAILA4. r5EAS 7890, October 21, 1986 EM*:A?A?,%

.$@hilf Mr. Eric H. Johnson, Director I Division of Reactor Safety and Projects i OU 2 I E U. S. Nuclear Regulatory Commission L, j 611 Ryan Plaza Drive, Suite 1000 Arlington, TX 76012

SUBJECT:

COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)

DOCKET NO. 50-445 AND 50-446 CABLE TRAY HANGER DESIGN SDAR: CP-85-35 (INTERIM REPORT)

Dear Mr. Johnson:

On September 6,1985, we verbally notified your Mr. C. Gould of a deficiency involving the design and construction activities of the cable tray hanger program. Our latest report, logged TXX-4884, was submitted on June 27, 1986.

We are reporting this issue under the provisions of 10CFR50.55(e) and the required information follows.

DESCRIPTION Cable tray supports were originally installed in accordance with general criteria including standard support designs and associated guidelines based on tray configurations, loads, and span lengths. The criteria were based on equivalent static analysis methods for assessing seismic loads. Where field conditions precluded the application of standard designs, design changes were reviewed, approved, and issued as qualified specific support designs.

As a result of design and construction related concerns raised by external sources, EBASCO and IMPELL have been directed to perform a 100% verification of the cable tray system design. These design activities are being conducted in accordance with CPRT Program Plan Item DSAP VIII, which includes third-party overview to assure resolution of the issues and compliance to licensing commitments.

Evaluation of this issue has progressed to the stage that modifications of some supports are required to meet the FSAR criteria. Since the program implements required modifications, no evaluation has been performed of the safety consequences had these potential deficiencies remained undetected.

This item is applicable to Units 1 and 2.

8610280431 861021 DR ADOCK 0500 5 SAFETY IMPLICATIONS g Failure of seismic category cable tray supports to meet the required design criteria could result in an inability of associated safety-related systems to perform as required for safe operation and shutdown.

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DALLAS-SLIC TEL No. 214 979 8700 Oct 21.86 17:06 P.05 i

TXX-6048 October 21,'1986

'. Page 2 of 3 m IDRRECTIVE ACTION The verification program is being implemented for Units 1 and 2. The primary difference between the two units is related to the inaccessibility of hardware for Unit I due to the advanced state of construction.

For Unit 1, a number of the support design attributes are inaccessible as a result of congestion or the presence of fire protection material. Our approach in the development of these as-built drawings is as follows:

0 As-designed drawings have been developed for each support. These drawings are based on the original design and include design changes generated in the construction / design process.

O Field walkdowns have been performed using the as-designed drawing.

For all accessible supports and accessible portions of partially inaccessible supports, as-built conditions were confirmed or noted as different on the as-designed drawing. Final as-built drawings were produced specifically noting any items within the scope of the walkdown that were inaccessible. Quality Control verification of as-built drawings is currently in process.

O Span sketches (noting span lengths) have been developed based on field inspections of Unit I supports.

For Unit 2, where almost all attributes are accessible, as-built verification is being accomplished by direct field inspection of design attributes and the production of as-built drawings for each support.

Unit 2 design verification is performed using maximum cable tray fill weights, and conservative assumptions regarding the weight of fire protection material.

The equivalent static analysis method is typically used to determine sup) ort loads. The response spectrum method is being used to justify limiting tie scope of modifications that would be difficult to implement in a congested environment.

Design verification based on as-built conditions is currently in process. The l

basis for design review of inaccessible items for Units 1 and 2 has been address 2d and documented in specific studies or reports.

For both units, loading combinations and stress limits are checked in accordance with acceptance criteria which conforms to CPSES licensing commitments.

A testing program has been established to augment the cable tray support verification effort. The testing program is anticipated to be complete in .

November, 1986. Evaluation of the test results should be performed by late December, 1986.

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DALLAS-SLIC TEL No. 214 979 8700 Oct 21.86 17:06 P.06 TXX-6048 October 21, 1986 Page 3 of 3 The design verification program addresses all cable tray support issues in an integrated manner. It will confirm that the design criteria is met or result in modifications to conform with design criteria. A number of modifications (approximately 800 hangers) have already been implemented in Unit 2 and a significantly lesser amount of hangers in Unit I have been identified as requiring potential modifications. To achieve qualification, all modifications will be inspected for as-built conditions and the design will be verified.

Based on the projected schedules for testing and engineering evaluations, it is anticipated that our next report will be submitted by January 30, 1987.

Very truly yours.

W. G. Coun i By:

G. S. Keeley - /

Manager,Nuclearycensing JCH/amb 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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