ML20211G274

Requests Rept on Design Min Wall Thickness in Identified Locations,Method/Criteria for Determining Design Thickness, Actual Measured Thickness in Locations & Conditions of Coatings on Inside of Torus

ML20211G274
Person / Time
Site:	Hatch
Issue date:	09/23/1997
From:	Le N NRC (Affiliation Not Assigned)
To:	Sumner H SOUTHERN NUCLEAR OPERATING CO.
References
NUDOCS 9710020180
Download: ML20211G274 (4)

Text

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NUCLEAR REGULATORY COMMISSION t,

"$ep$e"in$er' D997 Mr. H. L. Sumner, Jr.

Vice President - Nuclear Hatch Project Southem Nuclear Operating Company, Inc.

Post Office Box 1295 Birmingham, Alabame 35201-1295

SUBJECT:

VERIFICATION OF ADEQUATE WALL THICKNESS FOR MARK i TORUS SHELLS - EDWIN 1. HATCH NUCLEAR PLANT, UNITS 1 AND 2

Dear Mr. Sumner:

The NRC staff is concemed about torus thinning that may have occurred as a result of corrosion of the steel shellin areas that have defective or missing coatings, and, thus, we are requesting information relating to the rninimum Code wall thickness of the torus structure in the Mark I containments for the Edwin I. Hatch Nuclear Plant (Hatch), Units 1 and 2.

We are requesting information based on the results of your inspections of the Hatch torus structures at the following locations: in the vicinity of the torus-to-ring girder support welds; at the air-water interface; and in submerged areas to determine if the wall thicknesses at these locations are below the Code allowables. While UT thickness measurements would usually be made from the outside of the torus structure, it is important that the condition of the coatings on the inside of the torus structure be visually inspected as well.

Your verification that the Hatch torus wall thicknesses meet the minimum wall thickness requirements can be accomplished by reviewing the results of your recent inspections or by additionalinspections of the torus structure.

Please submit a report providing the design minimum wall thicknesses in the identified locations, the method / criteria for determining their design thicknesses, the actual measured thickness in these locations, the condition of the coatings on the inside of the torus, and the dates when these measurements and/or observations were made. If you identify degradation, you should also provide an assessment of the condition and long-term integrity of the degraded torus.

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4 Mr, H. L. Sumner, Jr. if you determine that you need to do additionalinspections, please provide the infonnation currently available within 60 days. The additionalinspections should be conducted at the next outage of sumcient duration. If you have any questions regarding this matter, please contact me at 301-415-1458.

Sincerely, w

Ngoc B. (Tommy) Le, Project Manager Project Directorate ll 2 Division of Reactor Projects - 1/11 Office of Nuclear Reactor Regulation Docket Nos. 50-321 and 50-366 cc: See next page h

i-Edwin 1. Hatch Nuclear Plant cc:

Mr. Ernest L. Blake, Jr.

Shaw, Pittman, Potts Charles A. Patrizia, Esquire and Trowbridge Paul, Hastings, Janofsky & Walker 2300 N Street, NW.

10th Floor Washington, DC 20037 1299 Pennsylvania Avenue

. Washington, DC 20004 9500 Mr. D. M. Crowe Chairman Manager, Licensing Southern Nuclear Operating Appling County Commissioners Company, Inc.

County Courthousa P. O. Box 1295 Baxley, Georgia 31513 Birmingham, Alabama 35201-1295 Mr. W. G. Harriston,111 Resident inspector President t.nd Chief Executive Plant Hatch Officer Southern Nuclear Operating Southem Nuclear Operating Company, Inc.

Company, Inc.

P. O. Box 439 P. O. Box 1295 Baxley, Georgia 31513 Birmingham, Alabama 35201-1295 Regional A'dministrator, Region ll Mr. J. D. Woodard

- U.S. Nuclear Regulatory Commission Executive Vice President Atlanta Federal Center Southem Nuclear Operating 61 Forsyth Street, SW, Suite 23T85 Company, Inc.

Atlanta, Georgia 30303 P. O. Box 1295 Birmingham, Alabama 35201 1295 Mr.- Charles H. Badger Mr. P. W. Wells Office of Planning and Budget Room 610 General Manager, Edwin 1. Hatch 270 Washington Street, SW.

Nuclear Plant Atlanta, Georgia 30334 Southem Nuclear Operating Company, Inc.

Harold Reheis, Director P. O. Box 439 -

Department of Natural Resources Baxley, Georgia 31513 205 Butler Street, SE., Suite 1252 Atlanta, Geor0ia 30334 Mr. R. D. Barker Program Manager Steven M. Jackson Fossil & Nuclear Operations Senior Engineer - Power Supply Oglethorpe Power Corporation Municipal Electric Authority 2100 East Exchange Place of Georgia P. O. Box 1349 1470 Riveredge Parkway, NW Tucker, Georgia 30085-1349 Atlanta, Georgia 30328 4684 i

Mr. H. L. Sumner, Jr. September 23, 1997 If you determine that you need to do additionalinspections, please provide the information currently available within 60 days. The additionalinspections should be conducted at the next outage of sufficient duration. If you have any questions regarding this matter, please contact me at 301-415-1450.

Sincerely, ORIGINAL SIGNED BY:

Ngoc B. (Tommy) Le, Project Manager Project Directorate 112 Division of Reactor Projects - 1/11 Office of Nuclear Reactor Regulation Docket Nos. 50 321 and 50-336 cc: See next page DistributiqIn (OuehetMlet HBerkow ACRS PUBLIC LBerry JJohnson, Rll PD ll 2 Rdg.

NLe PSkinner, Ril BBoger JStrosnider JZwolinski OGC To receive a copy of this document, Indicate in the box: "C" = Copy without attachment / enclosure "E" = Copy with cttachment/ enclosure "N" = No copy *See previous con'ckence OFFICE PM:PDll-2, LA:PDil-2 BC:EMQBf D:PDK.$ )

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