ML20207Q245

Forwards Request for Addl Info Re TVA Thermal Analyses for Equipment in Main Steam Line Valve Vaults,Per Review of Plant Equipment Qualification Under Superheat Conditions. Response Requested within 30 Days of Ltr Date

ML20207Q245
Person / Time
Site:	Sequoyah
Issue date:	01/20/1987
From:	Youngblood B Office of Nuclear Reactor Regulation
To:	White S TENNESSEE VALLEY AUTHORITY
References
NUDOCS 8701270070
Download: ML20207Q245 (4)

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• Docket Nos.: 50-327 )

and 50-328 Mr. S. A. White 20 W Manager of Nuclear Power 1

• iennessee Valley Authority i EN 38A Lookout Place 1101 Market Street 1 Chattanooga, Tennessee 37402-2801 '

Subject:

Sequoyah's Equipirent Qualification Under Superheat Conditions The staff, in its review of the above subject, requests additional information relating to the TVA thermal analyses for equipirent in main steam line valve vaults. Your response to the enclosed questions is requested within 30 days from the date of this letter. ,

Following your response and our staff review of your response, a meeting will prcbably be needed to expedite the review. If you have any questions contact

. Joe Holonich at (301) 492-7270 or Tom Alexion at (301) 492-7386.

Sincerely, B.J. Youngblood, Director PWR Project Directorate #4 Division of PWR Licensing-A Enclost re: As stated cc: See next page DISTRIBUTION:

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i Request for Additional Information  ;

Relating Component Selection and Heat Transfer Analysis  !

in Support of Equipment Qualification for Sequoyah Units 1 and 2 The following questions arise from the review of TVA's December 23', 1986 submi,ttal and the telephone conference of January 7,1987 between members of the NRC, TVA, and FRC staffs.

I j 1. Page 2 of the December 23, 1986 TVA submittal states that: "The equipment that would heat up most during the steam line break were the ones with the least thermal inertia. The value vault equipment lists were reviewed and components with low mass and thin housings ,

i were selected for analysis."

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During the January 7,1987 conference call, TVA stated all Class A and B components in the vaults had either been tested or thermally .,

analyzed to verify that internal temperatures were enveloped by the existing qualification results.

Accordingly

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a. Confirm that all Class A and B equipment in the valve vaults 4 have been tested or thermally analyzed and that none had been i eliminated through an engineering judgment process (e.g.,

! items with high thermal mass were eliminated from the thermal analysis).

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b. For the Class A and B equipment listed in the December 23, 1986 submittal, state which pieces of equipment have now been tested to determine internal temperatures. Also, identify those equipment items for which the thermal analysis remains as the means of determining the internal temperature.

2. In accordance with the discussion of January 7,1987, confirm that any Class A and B equipment in the valve vaults that was originally I

listed as requiring MSLB qualification but that now will be relocated outside of the valve vaults will be relocated prior to restart.

Provide a list of such equipment.

3. Page 4 of the TVA submittal states: "All of the cables located in the valve vault are routed through conduits and are terminated in junction boxes."

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' In light of NRC-sponsored research which demonstrated high leakage currents on instrumentation signals as well as terminal-to-terminal i

shorting of power and control terminations exposed to the effects of a LOCA/MSLB event, provide the test data or analyses which ,

demonstrate the acceptability of the terminations for use in a steam i

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i environment or provide a description of any housings that preclude i condensation of moisture from the steam upon the terminal blocks. j

4. Confirm that the Masoneillan Model 120 level control valve >

positioners and associated ASCO solenoid operated valves no longer require MSLB qualification. Provide a description of the justification for the change in classification.

5. Provide the values of the convective and condensation heat transfer coefficients used to account for the heat flow between the MSLB environment and the outer surface of the equipment housings.

6. For all of the equipment which is being qualified by thermal analysis, provide the models used in the thermal analyses and actual dimensions of equipment.

7. At which point or points inside the conduit was the temperature I measured during the MSLB cable type test (i.e., was the measurement made in the air space or at the cable surface)?

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9 Mr. S.A. White Tennessee Valley Authority Sequoyah Nuclear Plant 4

cc:

Tennessee Department of Public Regional Administrator, Pegion II Health U.S. Nuclear Regulatory Commission, ATTN: Director, Bureau of 101 Marietta Street, N.W., Suite P900 Environmental Fealth Services Atlanta, Georgia 30323 Cordell Hull Building Nashville, Tennessee 37219 J.A. Kirkebo ATTN: D.L. Williams Mr. Michael H. Mobley, Director Tennessee Valley Authority Division of Radiological Health 400 West Summit Hill Drive, W12 A12 T.E.R.R.A. Building Knoxville, Tennessee 37902 150 9th Avenue North Nashville, Tennessee 37203 Mr. Bob Faas Westinghouse Electric Corp. County Judge P.O. Box 355 Hamilton County Courthouse Pittsburgh, Pennsylvania 15230 Chattanooga, Tennessee 37402 R. L. Gridley Tennessee Valley Authority 5N 157B Lookout Place Chattanooga, Tenr.essee 37402-2801 M. R. Harding Tennessee Valley Authority Sequoyah Nuclear Plant P.O. Box 2000 Soddy Daisy, Tennessee 37379 Resident Inspector /Sequoyah NPS c/o U.S. Nuclear Regulatory Commission 2600 foou Ferry Road Soddy Daisy, Tennessee 37374 H.L. Abercrombie Tennessee Valley Authority Sequoyah Nuclear Plant P.O. Box 2000 Soddy Daisy, Tennessee 37379

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