ML19347F854

Final Deficiency Rept Re Cable Tray Hanger Design,Initially Reported on 801205.Program Implemented to Identify & Correct Any Nonconforming Design Condition

ML19347F854
Person / Time
Site:	South Texas
Issue date:	05/18/1981
From:	Oprea G HOUSTON LIGHTING & POWER CO.
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
10CFR-050.55E, 10CFR-50.55E, ST-HL-AE-668, NUDOCS 8105260474
Download: ML19347F854 (5)

Text

l The Light ShE Uf Houston Ughting & Power P.O. Box 1700 Houston, Texas 77001 (713)228-9211 May 18, 1981 ST-HL-AE-668 SFN: V-0530 m

Mr. Karl Seyfrit -

U Director, Region IV t:

Nuclear Regulatory Commission -I 611 Ryan Plaza Drive, Suite 1000 i Arlington, Texas 76012 .

Dear Mr. Seyfrit:

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Units 1 & 2 Docket Nos. STN 50-498, STN 50-499 Final Report Concerning Cable Tray Hanaer Desian On December 5, 1980, in accordance with 10CFR50.55(e), Houston Lighting &

Power Company notified your office of an item involving the cable tray hanger design for the South Texas Project. The final report on this item has been attached.

If you have any question, please contact Mr. M. E. Powell at (713) 676-8952.

Very truly yours, Exe a.

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ivedt'ce President RRH/aaj Attachments OI VJI '

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81052604 74

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Houston Lighting & Power Company May 18,1981 cc: J. H. Goldberg ST-HL-AE-668 D. G. Barker SFN: V-0530 C. G. Robertson Page 2 Howard Pyle R. L. Waldrop H. R. Dean D. R. Beeth J. D. Parsons L. K. English J. W. Briskin R. A. F razar STP RMS H. S. Phillips (NRC)

J. D. Read (Read-Poland,Inc.)

M. D. Schwarz (Baker & Botts)

R. Gordon Gooch (Baker & Botts)

J. R. Newman (Lowenstein, Newman.,Reis, & Axelrad)

Director, Office of Inspection & Enforcecent/

Nuclear Regulatory Commission Washington, D. C. 20555 M. L. Borchelt Charles Bechhoefer, Esquire President Chairman, Atomic Safety & Licensing Board Central Power & Light Company V. S. Nuclear Regulatory Commission P. O. Box 2121 Washington, D. C. 20555 Corpus Christi, Texas 78403 R. L. Range Dr. James C. Lamb, III Central Power & Light 313 Woodhaven Road P. O. Box 2121 Chapel Hill, North ~arolina 27514 Corpus Christi, Texas 78403 R. L. Hancock Mr. Ernest E. Hill Director of Electrical Utilities Lawrence Livermore Laboratory City of Austin University of California P. O. Box 1088 P. O. Box 808, L-123 Austin, Texas 78767 Livermore, California 194550 T. H. Muehlenbeck Citizens for Equitable Utilities, Inc.

City of Austin c/o Ms. Peggy Buchorn P. O. Box 1088 Route 1, Box 1684 Austin, Texas 78767 Brazoria, Texas 77422 J. B. Poston Pat Coy Assistant General Manager of Operations Citizens Concerned About Nuclear Power City Public Service Board 5106 Casa Oro P. O. Box 1771 San Antonio, Texas 78233

..n Antonio, Texas 78296 A. vonRosenberg Lanny Sinkin City Public Service Board 2207-0, Nueces P. O. Box 1771 Austin, Texas 78705 Sar Antonio, Texas 78296 Brian E. Berwick, Esquire day Gutierrez, Esquire Assistant Attorney for the State of Texas Hearing Attorney P. O. Box 12548 Office of the Executive Legal Director Capitol Station U. S. Nuclear Regulatory Conmission Austin, Texas 78711 Washington, D. C. 20555 pessegg

FINAL REPORT CONCERNING CABLE TRAY HANGER DESIGN I. Summary On December 5, 1980 in accordance with the requirements of 10CFR50.55(e), Houston Lighting & Power notified your office of an item concerning the design of the safety related cable tray hangers. During a routine Engineering review of the design for the safety related cable tray hangers it was identified that Field Engineering in transcribing a design standard the specific design connection detail was modified. As the design calculation referenced a structural standard detail this modification was not identified in the Engineering design verification process. At the time that this item was identified the design connection had been verified, fabricated and erected.

An engineering evaluation of the subject connection has determined that the connection would not fail if left uncorrected and thus it would not represent a significant safety hazard.

II. Description of the Incident During a routine design review, it was identified that a safety-related cable tray hanger connection between the hanger beam and vertical leg had been based in part on an improper cross reference to a cable tray hanger design standard. The specific connection involved a 21/2 inch wide plate which was welded on two sides of a connecting channel beam with a 1/4 inch weld. The design standard required a 3 inch wide plate with a 1/4 inch weld around the channel beam connection (Figure 1). At the time the design review identified the modified standard, the connection had been design verified, fabricated and erected.

i III. Corrective Acticn The investigation into the cause of this condition resulted in identification of a nonconformance with respect to the cable tray hanger design control process. A standard had been developed by Engineering for use by field personnel who were responsible for creating the detailed hanger design on field : ketches. The field sketches were then forwarded to Engin:.ering for design verification and incorporation into '.he standard. ProcetJres permitted fabrication and erection of hangers based on the field j sketenes with final inspection (acceptance) being performed l

against the design verified document. The design process, however, was not being followed in a timely fashion.

A program has been implemented to identify and correct any nonconforming design condition. As-built safety related cable l

tray hanger designs are being evaluated in accordance with the l latest design control procedures and actual loading conditions.

The connections will De modified as necessary to meet project

design requirements. Affected design documents will also be revised as required to reflect resultant design modifications.

IV. Recurrence Control The responsib!11ty for design and engineering of safety related l cable tray supports is now exclusively assigned to Engineering to preclude a recurrence of this condition. Additionally, the importance of checking cross references has been re-emphasized to design verifiers. Further the design control process has been revised to allow safety related cable tray hanger erection only on the basis of a documented and design verified drawing. ,

V. Safety Analysis An engineering analysis has been performed and has determined that the connection would not fail if left uncorrected and thus it would not represent a significant safety hazard.

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GENERAL NOTE:

DESIGN DETAILS NOT DRAWN TO SCALE AND SERVE TO ILLUSTRATE THE ITEM REPORTED.

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