ML19312E738

Interim Deficiency Rept Re Cracking of Control Rod Guide Tube Support Pins.Cracking Restricted to Pins Solution Annealed Below 1,800 F.Cracking of Tube Support Pins Have Potential for Release of Loose Parts Into Upper Core Region

ML19312E738
Person / Time
Site:	Millstone
Issue date:	04/15/1980
From:	Counsil W NORTHEAST NUCLEAR ENERGY CO.
To:
Shared Package
ML19312E737	List: ML19312E738
References
ACE-MP3-207, NUDOCS 8006090474
Download: ML19312E738 (1)

Text

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April 15,1980 United States Nuclear Regulatory Commission Office of Inspection and Enforcement Region I 631 Park Avenue King of Prussia, Pennsylvania 19406 ATTENTION: Mr. B. H. Grier, Director Docket No. 50-423 AEC-MP3-207 Gentlemen:

SUBJECT:

Millstone Unit No. 3 Reporting of Deficiencies in Design and Construction This letter provides written confirmation of a phone conversation held with your Mr. A. Cerne on March 17, 1980. We have determined that the problem as discussed below is reportable under 10 CFR 50.55(e)(1)(ii). ,

As reported to Mr. Cerne on March 17, ;980, our Nuclear Steam Supply System supplier for Millstone Unit No. 3, Westinghouse Electric Corporation, reported to Northeast Nuclear Energy Company that cracking was discovered in solution annealed stainless  !

steel control rod guide tube support pins. The cracking is apparently restricted to pins solution annealed below 18000F. Millstone Unit No. 3 guide tube support pins ]

were solution annealed below 18000F.

Cracking of control rod guide tube support pins has the potential for the release of loose parts into the upper core region. For this reason it is being reported as a significant deficiency.

Westinghouse will inspect two (2) operating United States plants to further define the problem. The results of these inspections will dictate future course of action.

We will inform you at a later date of the corrective action taken.

1 Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY l/ 731./,

Willi'am G. Counsil

$71/' .

l Vice President cc: Nuclear Regulatory Comission Office of Inspection and Enforcement Division of Reactor Operations Inspection Washington, D C. 20555 8006000h7P