ML20127J277

Updates Util Final Response to Actions 2 & 3 of NRC Bulletin 88-008 Re Thermal Stresses in Piping Connected to RCS

ML20127J277
Person / Time
Site:	Comanche Peak
Issue date:	01/20/1993
From:	William Cahill TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
IEB-88-008, IEB-88-8, TXX-93026, NUDOCS 9301250090
Download: ML20127J277 (3)

Text

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.--.o-Log # TXX-93026 File # 10119 903.6 Ref. # NRC8 88-08 7URECTRIC January 20, 1993

% lillam J. Cahllt, Jr.

Gunp M Prestent U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555

SUBJECT:

COMANCHE PEAK STEAM ELECTRIC STATION (CPSES) - UNIT 2 DOCKET NO. 50-446 FINAL RESPONSE FOR UNIT 2 TO NRC BULLETIN 88-08:

THERMAL STRESSES IN PIPlHG CONNECTED TO REACTOR COOLANT SYSTEMS REF: 1) Supplement No. 25 to NUREG-0797 Related to Operation of the Comanche Peak Steam Electric Station, Unit 2 (September 1992)

2) HRC letter from Thomas A. Bergman to William J. Cahill, Jr.,

dated September 17, 1992

3) TV Electric letter logged TXX-92500 from William J. Cahill, Jr., to the NRC dated October 20, 1992 Gentlemen:

NRC Bulletin 88-08 was issued by the NRC on June 22, 1988. It contained two reporting requirements applicable to CPSES. TU Electric's response to Reporting Requirement 1 of NRC Bulletin 88-08 was provided by:

o TU Electric letter logged TXX-88/66, f rom W. G. Counsil to NRC, dated October 31, 1988 (Units 1 and 2)

The purpose for this letter is to update TU Electric's response for Action 2 and 3 of Reporting Requirement 2 for Unit 2. For clarity, Reporting Requirement 2 and associated Actions 2 and 3 have been restated. The attachment provides the required affidavit, in accordance with the requirement of NRC Bulletin 88-08, that responses be submitted under oath or affirmation under the provisions of Section 182a, Atomic Energy Act of 1954, as amended.

Reportina RCaultemc01.1 Those addressees who determine that there are unisolable sections of piping that can be subjected to stresses from temperature oscillations that could be induced by leaking valves and that were not evaluated in the design analysis of the piping shall submit a letter within 30 days of completion of Actions 2 and 3. This letter should confirm that Actions 2 and 3 have been completed and describe the actions taken.

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TXX-93026 Page 2 of 2 Action 2 For any unisolable sections of piping connected to the RCS that may have been subjected to excessive thermal stresses, examine nondestructively the welds, heat-affected zones and high stress locations, including geometric discontinuities, in that piping to provide assurance that there are no existing flaws.

lu._ Electric f<eSponse to Action 2 Based on crack initiation and propagation analysis for Farley Unit 2, TV Electric and Westinghouse have concluded that a crack would not be _

initiated by thermal fatigue during the relatively short amount of time that Unit 2 has been at elevated temperature. Therefore, the non-destructive examination requirements of Action 2 are not considered applicable to Unit 2.

Action 3 Plan and implement a program to provide continuing assurance that unisolable sections of all piping connected to the RCS will not be subjected to combined cyclic and static thermal and other stresses that could cause fatigue failure during the remaining life of the unit. This assurance may be provided by 1) redesigning and modifying these sections of piping to withstand combined stresses caused by various loads including temporal and spatial distributions of temperature resulting from leakage across valve seats, 2) instrumenting this piping to detect adverse temperature dittributions, or 3) providing means for ensuring that pressure upstream from block valves which might leak is nonitored and does not exceed RCS pressure.

TV Electric Response to Action 3 TU Electric has implemented a Unit 2 program similar to the Unit 1 program as described in Reference 3.

Sincerely, .y b -

William J. Cahill, Jr.

CBC/tg Attachment c- Mr. J. L. Milhoan, Region IV Mr. T. A. Bergman, NRR Mr. B. E. Holian, NRR Resident Inspectors, CPSES (2) l

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Attachment to TXX-93026 Page 1 of 1 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION In the Matter of Texas Utilities Electric Company ) Docket No. 50-446 (Comanche Peak Steam Electric Station, Unit 2) )

AFFIDAVIT William J. Cahill, Jr. being duly sworn, hereby deposes and says that he is Group Vice President, Nuclear of TV Electric, the lead Applicant herein; that he is duly authorized to sim and file with the Nuclear Regulatory Commission this response to NRC Bulle 88-08 for the captioned facility; that he is f amiliar with the content t' .cof; and that the matters set forth therein are true and correct to the best of his knowledge, information and belief.

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William J. CahiTI, Jr.

Group Vice President, Nuclear STATE OF TEXAS )

i COUNTY OF SOMERVI)LL Subscribed and sworn to hsfore me, on this 20th day of January , 1993.

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