ML20079C335

Supplemental Deficiency Rept CP-87-062 Re Class 5 Pipe Supports.Initially Reported on 890907.Corrective Actions Stated in Ref Ltr Will Be Applied to Unit 2.Walkdowns & Analyses Will Be Completed Prior to Unit 2 Fuel Load

ML20079C335
Person / Time
Site:	Comanche Peak
Issue date:	06/14/1991
From:	William Cahill TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
CP-87-062, CP-87-62, TXX-91222, NUDOCS 9106190236
Download: ML20079C335 (2)

Text

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903.9 71/ELEC7RlC Ref. # 10CFR50.55(e)

June 14, 1991

% I?tiam J. Cahlil. Jr.

Drawow Vkr henknt U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555

SUBJECT:

COMANCHE PEAL STEAH ELECTRIC STATION (CPSES)-UNIT 2 DOCKET NO. f0-446 CLASS S PIPE SUPPORTS SDAR: CP 87 062 (SUPPLEMENTAL REPORT)

Ref: TV Electric letter from William J. Cahill to NRC dated September 7, 1989 TXX-89651 Gentlemen:

9n August 24, 1987 TU Electric orally notified the NRC of deficiencies in the use of nomographs to design seismically supported Class 5 1arge bore piping systems. The final report on this issue was provided by the referenced letter. The final report described a program to demonstrate the adequacy of large bore non nuclear non-ASME Class 5 piping systems in Unit 1. This program applies earthquake experience to assess the integrity of Class 5 piping systems during the most severe postulated scismic event. This program was extensively reviewed by the NRC with results documented in Inspection Report 445/9003. In the referenced letter, TV Electric indicated that the corrective action required for Unit 2 would be assessed upon resumption of the balance of Unit 2 engineering activities.

The corrective actions stated in the referenced letter will also be applied to Unit 2. In summary, the objective of the program is to demonstrate the adequacy of Class 5 pipe supports by selecting a bounding sample consisting of the least conservative seismic design configuratic:4 and proving the acceptability of those configurations by analysis. The walkdowns and analyses will be completed prior to Unit 2 fuel load.

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400 North Ohve Street L H. 81 Dallas, Texas 75201 / I F [u 46 s FDR E

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TXX 91222 Page 2 of 2 TV Electric has taken action to preclude rec'rrence of this deficiency.

Changes have been made to the applicable Design Basis Document to require that nomographs be utilized only in accordance with approved engineering procedures. These procedures contain specific criteria for use of nomographs including the limitations and exclusions on when such methods are not appropriate.

Sincerely, t

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W. J. Cahill, J'.

HAM /gj cc: Mr. R. D. Hartin, Region IV Resident inspectors, CPSES (2)

Mr. H. Fields. NRR

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