ML20087E397

Final Deficiency Rept CP-87-64 Re Pressure Relieving Capacity of Tornado Venting Devices.Initially Reported on 870824.Existing Tornado Venting Analysis Validated to Assure Differential Pressures Are Correct

ML20087E397
Person / Time
Site:	Comanche Peak
Issue date:	01/14/1991
From:	William Cahill TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
CP-87-64, TXX-92011, NUDOCS 9201210206
Download: ML20087E397 (2)

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, me am. Log # TXX-92011 MM File # 10110

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Ref. # 10CFR50.55(e)

TUELECTRIC January 14, 1991 William J. Cahill, Jr.

Group ntinsident U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555

SUBJECT:

COMANCHE PEAK STEAM ELECTRIC STATION (CPSES) - UNIT 2 DOCKET NO. 50 446 DESIGN BASIS TORNADO ANALYSIS FOR SAFETY-RELATED E00lPHENT SDAR CP-87-64 (FINAL REPORT)

Gentlemen:

On August 24, 1987 TV Clectric orally notified the NRC of a potentially reportable item involving the pressure relieving capacity of the tornado venting devices on Units 1 and 2. Specifically, the existing Design Basis Tornado (DBT) analysis did not include sufficient documentation to show conclusively that safety related equipment was qualified for the negative pressure transient expected during a DBT. The last report on this item was logged TXX-89751 dated November 15, 1989, which stated that Unit 2 correctiv?

• actions would be assessed upon resumption of the balance of Unit 2 engineering activities.

The corrective actions completed on Unit I were two-fold:

1)- Validate the existing tornado venting analysis to assure that the differential pressures to which safety-related equipment would be subjected in the event of a DBT are correct, and

2) Validate the component adequacy or operability of affected safety-related equipment using the validated differential pressures.

The corrective actions in Unit 2 are the same. Calculations have now validated the tornado venting analysis for Unit 2 and the results are comparable to the validated Unit I results. Validation of Unit 2 component adequacy or operability of affected safety-related equipment will be completed using the validated Unit 2 DBT differential pressures in accordance with approved project procedures. This activity will be complete prior to Unit'2 fuel load.

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TkX92011 Page 2 of 2 TXX-89751 also stated that appropriate actions were being taken to ensure that affected equipment or components procured since January 20, 1988, were adequate to withstand the effects of a DB1 and that future procurement activities will properly consider the DBT design criteria. These procurement activities apply to Unit 2 as well as to Unit 1.

Sincerely, t2 j s William J. ehill, Jr.

CBC/JTC/fds cc: R. D. Martin, Region IV Regional Inspectors, CPSES (2)

M. B. Fields NRR