ML20080J833

Responds to IE Bulletin 84-01 Re Insp of BWR Mark I Containments Currently in Shutdown.No Cracks Found During Visual insp.Through-wall Crack on Main Vent & Vent Header Assembly Considered Very Unlikely.Insp Details Encl

ML20080J833
Person / Time
Site:	Dresden
Issue date:	02/10/1984
From:	Ryback B, Rybak B COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
6026N, IEB-84-01, IEB-84-1, NUDOCS 8402150210
Download: ML20080J833 (3)

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N Commonwealth Edison C ) DresdIn Nucler.r Power St1 tion i ge R.R. # 1

\ Morris, Illinois 60450

Telephone 815/942-2920 1

February 10, 1984 Mr. James G. Keppler, Regional Administrator Directorate of Inspection and Enforcement -

Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137

Subject:

Dresden Units 2 and 3 I

Response to I.E.Bulletin 84-01 NRC Docket No. 50-237 and 50-249

Dear Mr. Keppler:

The subject Bulletin requested specific actions to be taken for BWR units with Mark I containments which are currently in shutdown. .

- Dresden Unit 3 is currently in a refueling outage and lus complied with the required inspection. No cracks were found during the visual inspection. The results of the inspection is detailed in the Attach-ment to this letter.

To the best of my knowledge and belief, the statements contained in the Attachment are true and correct. In some respects, t'ase state-ments are not based on my personal' knowledge but upon information furnished by other Commonwealth Edison employees, consultants and contractors. Such information has been reviewed in accordance with Company practice and I believe it to be reliable.

Please address any questions that you or your staff may have concerning our response to I.E. Bulletin No. 84-01 to this office.

t.

8402150210 840210

{DRADOCK 05000237 PDR 6

., .. _ _ _ = _ _ _ _ _ _. . _ _ _ . . _ _ _ - .

Mr. James G. t.eppler February 10, 1984 Page 2 k

One,(1) signed original with' Attachment is being sent directly to the U.S. NRC Document Control Desk in Washington, DC for reproduction and distribution as requested in the Bulletin, j Respectfully, h, L%fD j- , B.Ryfa Nuclee Licensing Administrator

BR

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/

Attachment cc: U.S. NRC, Document Control Desk /

Washington, DC 20555 RIII Inspectors - DR  !

R. Gilbert - NRR SUBSCRIBED and SWORN to before me this //)/L ' day  !

of ' /eldinu , e

, 1984

% j e .t ). >yb$:

Notary Public 6026N l

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Attachment Dresden Unit 3 Inspection i In Response to 1.E.Bulletin 84-01 In response to I.E.Bulletin 84-01, an inspection of the Unit 3 Drywell Main Vents and Vent Header was performed on February 4, 1984 at 0900 hours0.0104 days <br />0.25 hours <br />0.00149 weeks <br />3.4245e-4 months <br />. The

-inspection was performed by qualified VT-1 visual inspectors following the guidelines for inspection outlined in Visual Examination Procedure VT-1-1.

The inspection consisted of a comprehensive internal and external inspection of all Main Vent and Vent Header welds. A complete circumferential external inspection of Vent Header welds visually accessible from the catwalk inside the torus was performed. The area of the Vent Header below the nitrogen inerting inlet was thoroughly inspected by walking on the top portion of the Vent Header approximately half-way around to ensure that any thermal cycling which might have occurred had not effected structural integrity. The inter-nal inspection was conducted by entering a Main Vent via the missle shield in

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the drywell to walk down and visually inspect the entire Vent Header. No vi.sual indications of weld fatigue were observed as a result of the Unit 3 Main Vent and Vent Header inspection.

The Unit 2 Main Vent and Vent Header assembly is believed to be in good operating condition. Unit 2 drywell to' torus differential pressure is readily maintained with no recent history of an abnormal differential pressure trend. Nitrogen make-up to the drywell was also reviewed with no evidence of excessive make-up being required. -The pump back air compressors were observed to be cycling in a manner. consistent with normal operation. Therefore, a through wall crack on the Main Vent and Vent Header assembly is considered very unlikely.

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