ML20206N377

Forwards Safety Evaluation Re Undefined Eddy Current Signals in Steam Generators.Study Re Steam Generator Tube Ends,W/ Proposed Corrective Action Plan,Should Be Completed by 860930.License Amend Should Be Submitted by 861031

ML20206N377
Person / Time
Site:	Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date:	06/26/1986
From:	Charemagne Grimes Office of Nuclear Reactor Regulation
To:	Opeka J NORTHEAST NUCLEAR ENERGY CO.
Shared Package
ML20206N381	List: ML20206N377 ML20206N400
References
NUDOCS 8607010447
Download: ML20206N377 (4)

Text

..

r[**'%[';,

UNIT ED STATES NUCLEAR REGULATORY COMMISSION h., J h $a vlj.

WASHINGTON, D. C. 20555 s

..... June 26, 1986 Docket No.: 50-213 Mr. John F. Opeka, Senior Vice President Nuclea ingineering and Operations Northeast Nuclear Energy Company Post Office Box 270 Hartford, Connecticut 06141-0270

SUBJECT:

UNDEFINED SIGNALS OBSERVED DURING STEAM GENERATOR TUBE EDDY CURRENT INSPECTION Re: Haddam Neck In a conference call on June 20, 1986, the Connecticut Yankee Atomic Power Company (CYAPC0) informed the NRC headquarters staff and Region I that, using advanced eddy inspection equipment, 575 steam generator (SG) tube ends were identified during the 1986 refueling as having " undefined eddy current signals" in the roll expansion region. CYAPC0 stated that no actions were taken during the outage, as the nature of the signals is unknown and characterization of the anomalies could not be performed.

4 However, a post-outage investigation is being conducted in an attempt to -

characterize the undefined signals.

These findings were presented in a letter dated June 20, 1986, which concluded that the potential flaws do not represent an undue risk to the public health and safety.

j As described in the enclosed evaluation, we conclude that there is reasonable

! assurance that the potential flaws associated with these signals will not result in catastrophic tube failure in the near term and that any propagation of existing flaws will be revealed by an increased primary-to-secondary coolant l leakage rate, which is limited by plant technical specifications. On this l basis, the staff concludes that plant operation does not present an undue j risk to the public health and safety while this evaluation is being conducted

and is, therefore, acceptable.

I The criteria for steam generator tube integrity in Section 4.10.1.D of the plant technical specifications do not separately define the criteria for integrity of the tube ends in the region of the tubesheet. Moreover, the definitions of " plugging limit" and " unserviceable" in the technical speci-fications are not clear in this respect. We agree that it is appropriate t

l 8607010447 DR 860626 g ADOCK 05000213 PDR

Mr. John F. Opeka for 'you to complete an evaluation which will serve as the basis for a license amendment to specify the acceptance criteria for the steam generator tubes in the tubesheet region.

In view of the quantity of SG tube ends with undeffned signals and the results of the destructive examination of a single tube end sample taken during the outage with an 82% through-wall crack, we require that your study regarding the SG tube ends, with a proposed corrective action plan, be completed no later than September 30, 1986. A license amcadment, with the appropriate inspection criteria for the tube ends, should subsequently be submitted by October 31, 1986. Further, we propose that a meeting be held with the NRC

~

staff toward the end of August 1986 to discuss any preliminary results regarding the significance of the undefined eddy current signals.

Sincerely, W 4Q W -

Christopher I. Grimes, Director Integrated Safety Assessment Project Directorate Division of PWR Licensing - B

Enclosure:

As stated cc w/ enclosure:

See next page i

l i

l

.. &M h-e-June 26, 1966 Mr. John F. Opeka for you to complete an evaluation which will serve as the basis for a license amendment to specify the acceptance criteria for the steam generator tubes in the tubesheet region.

In view of the quantity of SG tube ends with undefined signals and the results of the destructive examination of a single tube end sample taken during the outage with an 82% through-wall crack, we require that your study regarding the SG tube ends, with a proposed corrective action plan, be completed no later than September 30, 1986. A license amendment, with the appropriate inspection criteria for the tube ends, should subsequently be submitted by October 31, 1986. Further, we propose that a meeting be held with the NRC staff toward the end of August 1986 to discuss any preliminary results regarding the significance of the undefined eddy current signals.

Sincerely, Original signed by Christopher I. Grimes Christopher I. Grimes, Director Integrated Safety Assessment Project Directorate

, Division of PWR t.icensing - B

Enclosure:

DISTRIBUTION As stated Docket File PAnderson NRC PDR ACRS (10) cc w/ enclosure: Local PDR JDurr, Reg. I See next page ISAP Reading FAkstulewicz CGrimes DCrutchfield OELD FMiraglia EJordan MBoyle BGrimes JPtrt; s AWar, gwkSAP:DPL-B I AWang:mn P on

-B D:1 SAP:DP CGrimes EB:Dl h 1 DC field C /X /86 (, 86 L/g/86 </7[/86 4 yf786

/

f ia 86 f

.t Mr. John F. Opeka Connecticut Yankee Atomic Power Company Haddam Neck Plant cc:

Gerald Garfield, Esquire Kevin McCarthy, Director Day, Berry & Howard Radiation Control Unit Counselors at Law Department of Environmental City Place Protection Hartford, Connecticut 06103-3499 State Office Building Hartford, Connecticut 06106 Superintendent Haddam Neck Plant Richard M. Kacich, Supervisor RDF #1 Operating Nuclear Plant Licensing Post Office Box 127E Northeast Utilities Service Company East Hampton, Connecticut 06424 Post Office Box 270 Hartford, Connecticut 06141-0270 Edward J. Mroczka Vice President, Nuclear Operations Northeast Utilities Service Company Post Office Box 270 Hartford, Connecticut 06141-0270 Board of Selectmen Town Hall Haddam, Connecticut 06103 State of Connecticut Office of Policy and Management ,

ATTN: Under Secretary Energy -

Division 80 Washington Street Hartford, Connecticut 06106 Resident Inspector Haddam Neck Nuclear Power Station c/o U.S. NRC East Haddam Post Office East Haddam, Connecticut 06423 Regional Administrator, Region I U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, Pennsylvania 19406 I

c .