ML19305C929

Interim Deficiency rept:3/8-inch Orifices Shown on Flow Diagram Failed to Appear on Fabrication Isometric.S&W Isometrics Also Found Deficient.Caused by Transfer of Info. Drawings Will Be Corrected & Orifices Added by Rework

ML19305C929
Person / Time
Site:	Millstone
Issue date:	02/25/1980
From:	Counsil W NORTHEAST NUCLEAR ENERGY CO.
To:
Shared Package
ML19305C927	List: ML19305C929
References
AEC-MP3-205, NUDOCS 8004100608
Download: ML19305C929 (2)

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February 25, 1980 United States Nuclear Regulatory Comission 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-MP3-205 Gentlemen:

SUBJECT:

Millstone Unit No. 3 Reporting of Deficiencies in Desion and Construction This letter provides written confirmation of a phone conversation held with your Mr. R. McGaughy on January 25, 1980. We have determined that the pro-blem as discussed below is reportable under 10CFR50.55(e)(1)(ii).

As reported to Mr. McGaughy on January 25, 1980, our Engineer Constructor for Millstone Unit No. 3, Stone & Webster Engineering Corporation, reported to Northeast Nuclear Energy Company that a design error had been found in the use of 3/8" orifices which provide the demarkation between the ANS Safety Class 1 and 2 pressure boundary. In nineteen (19) instances (out of 125 possible) 3/8" orifices shown on the flow diagram did not appear on the fabrication isometric. The isometrics are made up from Stone & Webster design drawings which were found to be deficient also. The error occurred in trans-ferring information from the flow diagram to the design drawing. Of the nineteen (19) spool pieces that should have contained orifices, fourteen (14) were fabricated and shipped to the site.

Failure to include the orifices in the sample lines would lead to a higher Reactor Coolant System leak rate in the event of a sample line failure. For this reason it is being repoeted as a significant deficiency.

Corrective action consists of correcting all nineteen (19) of the affected design drawings and the fabrication isometrics for the five spool pieces not 8004100 h[

yet released. For the fourteen (14) spool pieces already fabricated, Engineering & Design Coordination Report P-P2558 has been issued by Stone & Webster to have 3/8" orifices added to the lines in question by rework.

Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY

, Niddf.

William G. Co6nsil Vice President cc: Nuclear Regulatory Commission Office of Inspection and Enforcement Division of Reactor Operations Inspection Washington, D.C. 20555

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