ML20087P714

Final Significant Deficiency Repts SD-43 & 44 Re Inadequate Brown Boveri 480-volt Load Ctr Anchors & Flakt-Bahnson Air Handling Units.Initially Reported on 831007.Fillet Welds Used to Attach Load Ctrs

ML20087P714
Person / Time
Site:	Millstone
Issue date:	03/14/1984
From:	Counsil W, Sears C NORTHEAST UTILITIES
To:	Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
12, FO-430A, FO430A, FO431A, SD-43, SD-44, NUDOCS 8404090302
Download: ML20087P714 (2)

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General Offices

• Selen Street, Berlin. Connecticut

• ****"""**"""'***" P.O. BOX 270 J HARTFORD, CONNECTICUT 061414270 m .m. ,om. co,-

L g imarm. urwasis.as cow- (203) 666-6911 o ..uw. co,-

March 14,1984 Docket No. 50-423 F0430A F0431A Dr. Thomas E. Murley Regional Administrator Region I U. S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406

Reference:

(1) W. G. Counsil letter to T. E. Murley, B10939, dated November 8,1983.

Dear Dr. Murley:

Millstone Nuclear Power Station, Unit No. 3 Reporting of Potential Significant Deficiencies in Design and Construction:

Brown Boveri 480V Load Center Anchors (SD-43); and Flakt-Bahnson Air Handling Units (SD-44)

In an October 7,1983 telephone conversation between your Mr. 3. Robertson and our Mr. R. E. Lefebvre, Northeast Nuclear Energy Company (NNECO) reported two potential significant deficiencies in the construction of Millstone Unit No. 3 as required by 10CFR50.55(e).' SD-43 involves inadequate welds on seismic anchors used for Brown Boveri 480V load centers. SD-44 involves improper mounting hardware itsed to install cooling coils in Flakt-Bahnson air handling units.

With regard.to SD-44, Flakt-Bahnson supplied self tapping sheet metal screws with their units instead of bolts as described in the seismic analysis. Corrective action has been initiated to replace the sheet metal screws with bolts. However, a review by Flakt-Bahnson indicates that the screws would have been adequate had they remained in the units. It is therefore concluded that SD-44 does not constitute a significant deficiency for Millstone Unit No. 3.

SD-43 involves the use of plug welds instead of fillet welds to mount Brown Boveri 480V load centers to their sill plates. These load centers provide power to essential safety-related and accident mitigation systems. The anchorage details indicated on the Brown Boveri Electric Drawings and Instruction Manual are plug welds, however, the Seismic Qualification Report (BBEL report no. 33-49986-SS) references fillet welds.

/V 8404090302 G40314 PDR ADOCK 05000423 PDR g ,

4. .U A review of ' these welds ' by _ our ' architect-engineer, Stone and Webster Engineering . Corporation, -indicates that the plug welds are not adeqiate.

- Corrective actions have been initiated and fillet welds will be used to attach the

. load centers to their sill plates in accordance with the seismic qualification report. -In addition, the vendor will supply appropriately revised drawings.

! This constitutes _our final report closing out all items related to SD-43 and SD-44.' Internal reviews will continue to. investigate any generic implications concerning equipment mounting. -Shortcomings will be identified and resolved prior to plant start up. --

Based on a February 3,' 1984 ' telephone conversation between your Mr. T.

Elsasser and our Ms. P. Capello-Bandzes, this report is being provided on March 14,.1984 instead of February 1,1984. We trust that the 'above information

- satisfactorily responds to your concerns.

Very truly yours, r 00 .Qi.

W. G. Counsil Senior Vice President L

By: C. F. Sears Vice President Nuclear and Environmental Engineering

~

cc: Mr. R. C. DeYoung,' Director .

Division of Inspection and Enforcement

.U. S. Nuclear Regulatory Commission Phillips Building '

7920 Norfolk Avenue Bethesda, MD 20014 -

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