TXX-6011, Interim Deficiency Rept CP-86-62 Re Mininterpretation of Polar Crane Load Cases.Initially Reported on 860904.Weld Mods at Girder Seat & for Replacing Existing Rail Clips W/ Stronger Clips Will Be Implemented.Next Rept by 861219

Interim Deficiency Rept CP-86-62 Re Mininterpretation of Polar Crane Load Cases.Initially Reported on 860904.Weld Mods at Girder Seat & for Replacing Existing Rail Clips W/ Stronger Clips Will Be Implemented.Next Rept by 861219

ML20215F369
Person / Time
Site:	Comanche Peak
Issue date:	10/03/1986
From:	Counsil W TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	Johnson E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
CP-86-62, TXX-6011, NUDOCS 8610160175
Download: ML20215F369 (2)

Text

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• Log # TXX-6011 J File # 10110 903.8 TEXAS UTILITIES GENERATING COMPANY NKYWAY TOWER . 400 NORTH OtJVE STREEf E It. 88 . DALLAN, TEXAM 75201 October 3, 1986 WILLIAM G. COUNSIL

• arsivvws vics PMesoamt Mr. Eric H. Johnson, Director fj Division of Reactor Safety and Projects U. S. Nuclear Regulatory Commission j

E ~ 7$

611 Ryan Plaza Drive, Suite 1000 'J N Arlington, TX 76012

SUBJECT:

COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)

D0CKET NOS. 50-445 AND 50-446 POLAR CRANE SUPPORT STRUCTURE SDAR: CP-86-62 (INTERIM REPORT)

Dear Mr. Johnson:

On September 4,1986, we verbally notified your Mr. I. Barnes of a deficiency involving a misinterpretation of the polar crane load cases. We are reporting this issue under the provisions of 10CFR50.55(e) and the required information follows.

DESCRIPTION The load cases provided by the crane supplier (KRANCO) in the interface load drawing were not properly censidered in the design of the supporting structure. As a result, the design does not consider the load case of the horizontal load acting simultaneously with the uplift of the crane. The acequacy of the polar crane support structure was considered indeterminate pending further analysis.

The cognizant engineering contractor has evaluated this issue and determir,ed that the welds connecting the bottom flange of the girder and sole plate at the girder seat must be increased and the crane rail hold down clips must be replaced with heavier clips.

SAFETY IMPLICATION In the event that the interface loading containing the horizontal load acting

, simultaneously with vertical uplift load had remained undetected, it could i have adversely affected safety related structures, systems and components in the containment.

CORRECTIVE ACTION Design Change Authorizations (DCAs) have been prepared for Unit 1 to provide for weld modifications at the girder seat and for replacing existing rail clips with stronger clips. The schedule for implementation will be established no later than December 5,1986.

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.. diXM6011 October 3, 1986

.Page 2 We anticipate submitting our next report no later than December 19, 1986.

Very truly yours, f)

W. G. Counsil JCH/amb c - NRC Region IV (0 + 1 copy)

Director, Inspection & Enforcement (15 copies)

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

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