ML19309G003

Responds to IE Bulletin 79-13, Cracking in Feedwater Sys Piping. Util Conducted Insp During Aug 1979 Outage.Several Crack Indications in nozzle-to-pipe Welds of Both Steam Generators Were Found.All Repairs Completed

ML19309G003
Person / Time
Site:	Millstone
Issue date:	04/24/1980
From:	Counsil W NORTHEAST NUCLEAR ENERGY CO.
To:	Reid R Office of Nuclear Reactor Regulation
References
IEB-79-13, TAC-11348, TAC-11561, TAC-12505, TAC-42846, NUDOCS 8005020136
Download: ML19309G003 (2)

Text

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8005020l%ilD 5 NORTHEAST UTILITIES u P O. Box 270 1 y' 1'],*,"7,(',,'

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, HARTFORD CONNECTICUT 00101 L L A 5{55.5?5N"l::

Apiil 24, 1980 Docket No. 50-336 Director of Nuclear Reactor Regulation Attn: Mr. R. Reid, Chief Operating Reactors Branch #4 U. S. Nuclear Regulatory Commission Washington, DC 20555

References:

(1) B. H. Grier letter to W. G. Counsil dated June 25, 1979 transmitting I&E Bulletin No. 79-13 (2) B. H. Grier letter to W. G. Counsil dated October 17, 1979 transmitting I&E Bulletin No. 79-13, Revision 2.

(3) W. G. Counsil letter to R. Reid dated December 7, 1979 Gentlemen:

Millstone Nuclear Power Station, Unit No. 2 Feedwater System Piping Inspections Reference (1), as supplemented by Reference (2), requested Northeast Nuclear Energy Company (NNECO) to perform certain volumetric examinations of the feedwater piping system at Millstone Unit No. 2. Specifically, the Staff expressed concern with potential cracking of the feedvater system piping.

In response to References (1) and (2), during an unscheduled outage in August ,1979, NNECO performed the inspections required by References (1) and (2). The inspections identified several crack indications in the nozzle-to-pipe velds and the piping to first elbow welds of both steam generators.

As a result of the discovery of crack indications in the feedwater nozzle-to-pipe and pipe to first elbow welds, NNECO performed volumetric examinations of the remaining feedwater piping welds inside containment in accordance with the Bulletin requirements. These inspections did not reveal any unacceptable indications in any of the additional feedwater piping welds which were inspected.

8005020

o NNECO ultimately repaired the affected feedwater piping welds and a summary report of the feedwater piping repair program and associated o aservations and findings were provided in Reference (3).

Because of the wording of certain portions of References (1) and (2),

various interpretations regarding inspection requirements for those plants which have completed feedwater piping repair programs are possible.

To preclude the possibility of misinterpretation, NNECO hereby clarifies its position below.

As previously stated, NNECO has examined all feedwater piping velds to the first support and high stress points in the feedwater piping inside contairs;;ent at Millstcne Unit No. 2, and has affected repairs to the welds where crack l indications had been discovered. As reported in Reference'(3), it is NNECO's intention to re-examine only those welds where cracking had previously been identified. Specifically, Welds AC-G-1, AC-G-2, BC-G-1, and BC-G-2 vill be re-examined during the upcoming 1980 refueling outage. No further action regarding the remaining feedwater system piping welds and other areas is  ;

planned for the upcoming refueling outage.

l Wa trust you find the above information sufficient to satisfactorily disposition the Reference (1) and (2) requirements as they apply to Millstone Unit No. 2.

Confirmation of the acceptability of the above approach, in either verbal or written form, by June 13, 1980, would be most appreciated.

Very truly yours, NORTHEAST hUCLEAR ENERG,Y COMPANY W."G. Counsil Vice President l

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