ML20148J135

Responds to Requesting Development of Alternate Method to Produce Dimensional Data for Valve Wall Thickness Verification Program.Later Attempts to Ultrasonically Measure Valves Successful

ML20148J135
Person / Time
Site:	Yankee Rowe
Issue date:	03/07/1973
From:	Vandenburgh D YANKEE ATOMIC ELECTRIC CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20148J142	List: ML20148J135
References
NUDOCS 8011210198
Download: ML20148J135 (1)

Text

t l

1 j 3 .

YANKEE ATOMIC ELECTRIC COMPANY 4

g .

20 IURNPIKE ROAD, WESTBOROUGH. MASSACHUSETTS 01581 _

TLLEPHONE 617 366 9011 =:.-

March 7, 1973 United States Atomic Energy Commission 970 Broad Street Newark, New Jersey 07102 Attention: Directorate of Regulatory Operation Region I

References:

-(a) ' Operating License No. DPR-3 (Docket No. 50-29) N (b) Yankee letter to USAEC dated January 15, 1973 (c) USAEC letter to Yankee dated February 7,1973

Dear Sir:

l We informed you in Reference (b) that althodsh we had completed the valve wall thickness verification program at Yankee P. owe we had been unsuccessful in i ultrasonically measuring five of the eight reactor coolant loop isolation valves as a result of variations in grain structure. ,

Your reply, Reference (c), requested us to develop an alternate method which voule produce the necessary dimensional data and to advise you, within y 30 days, of our proposed program to accun.ulate this information.

We now wish to inform you that later attempts to ultrasonically measure thase valves were succesaful. A Sonic instrument was used with a recently de-veloped damped transducer which operates in the 1 Edz frequency range. Pre-vi: sly, a Krautkrater instrument was used with a 2h MHz transducer.

The measuretants revealed areas of tne valves that were below the minimum thickness requirements of Code ANSI B16 5 Weld overlay is currently being applied to thess areas to increase the wall thickness. We anticipate this werk will be completed by March 1h,1973  ;

y 7ne documentaticn package for the verification of the wall thicknesses of )

the eight reactor coolant loop isolation valves will te available at the plant .J for review by your inspector.

Very truly yours, ,

, _. Uvbb /

D. E. VandenburCh I Vice President

}

i 18011210[9f },

--ys-si.,i- -- - - - - - , - ---c.-r , - - . - . . . - e-' -r". - - - ---- ew'v--- ^ee '---5--