TXX-6052, Interim Deficiency Rept CP-86-46 Re Gould Battery Racks Transverse Bracing.Originally Reported on 860611.Engineering Procedure Revised to Provide More Detailed Instructions. Next Rept Anticipated by 870501
| ML20215L931 | |
| 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-86-46, TXX-6052, NUDOCS 8610290376 | |
| Download: ML20215L931 (2) | |
Text
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Log # TXX-6052 File # 10110 TEXAS UTILITIES GENERATING COMPANY 908.3 SKYWAY TOWER 400 NORTH OlJVE STRE'h:7.1.B Al. DALLAS. TEXAS 75308 October 21, 1986
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Mr. Eric H. Johnson W2iE j,
Division of Reactor Safety and Projects L
U. S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 1000 Arlington, Texas 76012
SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)
DOCKET N0. 50-446 G0ULD BATTERY RACKS TRANSVERSE BRACING SDAR:
CP-86-46 (INTERIM REPORT)
Dear Mr. Johnson:
On June 11, 1986, we verbally notified your Mr. C. Hale of a deficiency involving a design change to vendor supplied equipment being made without i
formal evaluation by the vendor. We have submitted interim reports logged TXX-4900 and TXX-5002, dated July 11, 1986 and September 5, 1986, respectively. We are reporting this issue under the provisions of 10CFR50.55(e) and the required information follows.
DESCRIPTION During preparation of a Unit 2 design change in 1983 involving vendor supplied equipment, conversations with the vendor (Gould) indicated the proposed change was acceptable pending evaluation of the final design change. Subsequent review of the design change indicates formal evaluation by TUGC0 has not been completed and was not scheduled for submittal to the vendor for formal review / approval.
The specific issue identified involves a design change revising the transverse bracing mounting bolt design from a two (2) bolt to a one (1) bolt configuration. An independent review and analysis of the one (1) bolt configuration has c.ncluded a two (2) bolt connection is required to insure adequate strength and avoid excess eccentricity. The one bolt connection could yield under seismic loads and cause loss of the transverse bracing allowing the battery racks to become unstable. This could result in collapse of the racks.
This applies to all Class IE battery racks in Units 1 and 2.
SAFETY IMPLICATIONS In the event the deficiency had remained undetected, the structural integrity of the battery racks could not be assured thereby affecting all associated safety systems dependent upon DC power.
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O TXX-6052 October 21, 1986 Page 2 CORRECTIVE ACTION The design change which authorized the one (1) bolt connection has been voided and the original design requirements reestablished, thus reverting back to the original design of the two (2) bolt connection.
TUGC0 Nuclear Engineering Procedure TNE-DC-8-1, " Engineering Review and Design Verification of Field Design Changes," (currently Rev.10) has been revised and now provides more detailed instructions and establishes a verifiable approval record of all design changes including calculations.
Completion of the associated rework is scheduled for April 15, 1987. We anticipate submitting our next renort no later than May 1, 1987.
Very truly yours, IDQ GmdC W. G. Cou sil By:
., v G.S. Keeley & /--
Manager, Nuclear / Licensing JCH/gj c - Region IV (Original + 1 copy)
Director, Inspection & Enforcement (15 copies)
U. S. Nuclear Regulatory Commission Washington, D. C.
20555
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