ML20053C884

Application to Amend License DPR-79,requesting Relief from Hydrostatic Test Requirements for MSIV Warming Line Per Article IWC-5000 of ASME Section XI,1975 Edition-Summer 1975 Addenda.W/Class III Amend Fee

ML20053C884
Person / Time
Site:	Sequoyah
Issue date:	05/27/1982
From:	Mills L TENNESSEE VALLEY AUTHORITY
To:	Adensam E Office of Nuclear Reactor Regulation
References
NUDOCS 8206030112
Download: ML20053C884 (5)

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TENNESSEE VALLEY AUTHORITY CH ATT ANOOG A. T ENN FSSCE 37401 400 Chestnut Street Tower II May 27, 1982 Director of Nuclear Reactor Regulation Attention: Ms. E. Adensam, Chief e Licensing Branch No. 4 Division of Licensing U.S. Nuclear Regulatory Commission Washington, DC 20555

Dear Ms. Adensam:

In the Matter of ) Docket Nos. 50-327 Tennessee Valley Authority ) 50-328 In accordance with 10 CFR Part 50, enclosed is our request for relief and the justification for relief from the hydrostatic test requirements for unit 2 of our Sequoyah Nuclear Plant, for a main steam isolation valve warming line, specified in Article IWC-5000 of ASME Section II,1975 Edition through Summer of 1975 Addenda. This request was discussed with Carl Stahle of your staff and representatives of NRC-OIE Region II in telephone conversations on May 25 and 26, 1982.

In accordance with the requirements of 10 CFR Part 170.22, we have determined the proposed request for approval to be Class III for unit 2.

This classification is based on the fact that a single safety issue is involved and the request applies only for one unit. The remittance fee of

$4,000 is being wired to the Nuclear Regulatory Commission, Attention:

Licensing Fee Management Branch.

If you have any questions concerning this matter, please get in touch with J. E. Wills at FTS 858-2683 Very truly yours, TENNESSEE VALLEY AUTHORITY L. M. Mills, Manager Nuclear Licensing Sworn subscribed before me this -day of @ W 1982 6"obb %. 4fA8 Notary Public My Commission Expires Enclosure cc: See page 2 1}

8206030112 820527 PDR ADOCK 05000328 p PDR  %,3aog . , , , , %.m .

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Director of Nuclear Reactor Regulation May 27, 1982 00: U.S. Nuclear Regulatory Commission Region II Attn: Mr. James P. O'Reilly, Regional Administrator 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303 l

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, . EMCLOSURE SEQUOYAH NUCLEAR PLANT - UNIT 2 MAIN STEAM ISOLATION VALVE WARMING LINE REQUEST FOR RELIEF 1.0 Background . ._

During the present unit 2 ice-weighing outage (May 14-29), it became necessary to remove a portion of the loop 1 main steam isolation valve warming line to provide physical access to perform machining operations on a feedwater check valve. The line in question is a 2-inch senedule 80, ASTM A-106 Gr B carbon steel socket welded line that was installed to class 2 requirements of ANSI B31.7,1969 Edition and 1970 Addenda. The line begins just upstream of main steam isolation valve FCV 1 4 and ties in to main steam check valve 1-623 (see attached sketch). The line was cut at welds 1173 and 1176, also shown on the attached sketch.

Once the machining of the feedwater check valve was completed, the portion of the line that was removed was socket welded back into its original configuration and liquid perietrant examined in accordance with the original construction code requirements. The timeframe in which this work was performed was May 19-22.

2.0 Request for Relief Article IWC-3000 of ASME Section XI, 1975 Edition through S'75 Addenda, which is the Inservice Inspection Code of Record for unit 2, requires that the two welds in question be hydrostatically tested at 1.25 times the system design pressure. To accomplish this will necessitate flooding the steam generator and the 32-inch diameter main steam line out to main steam check valve 1-623 In addition,~the loop 1 main steam safety and power-operated relief valves will have to be gagged to accomplish this test. We propose to perform a system leak test of the subject welds at operating pressure and temperature during the startup from the present outage. Therefore, we request the hydrostatic test requirement for these welds be waived.

• 3.0 Justification It is TVA's policy to minimize to the maximum extent practicable hydrostatic tests involving the secondary side of the steam generator and the main steam safety and relief valves. There is a very real danger of damaging support structures and safety-related valves whenever the steam generator and the main steam lines are flooded and pressurized.

Our justification for waiving the hydrostatic test requirements of the

subject welds is as follows

(1) the consequences of failure of the warming line in question are conservatively bounded by the major secondary system pipe break analysis, (2) the welds were liquid penetrant examined and met the construction code acceptance criteria, (3) the allowable working pressure at operating temperature for a 2-inch schedule 80 carbon steel pipe was calculated to be apprcvimately 3,000 psi whereas the system operating pressure is l approximately 1,000 pai. Therefore, the corresponding socket weld l

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, . size for this line has at least a factor of safety of 3 in addition to the conservatism already established by the construction code, and (4) the subject welds will be leak tested at operating pressure and temperature to demonstrate their integrity prior to the unit returning to service.

Based on the above justification, TVA concludes 'that the subject request for relief does not affect safe operation of the unit.

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