ML17037C111

Letter Regarding Action Taken in Response to a June 22, 1972 Letter Relating to Wall Thickness of Nuclear Service Valves

ML17037C111
Person / Time
Site:	Nine Mile Point
Issue date:	08/10/1972
From:	O'Reilly J US Atomic Energy Commission (AEC)
To:	Schneider F Niagara Mohawk Power Corp
References
Download: ML17037C111 (6)

Text

0('E( I UN1TED STATES ATOMlC ENERGY COM~~lON DIVISION OF COMPLIANCE 20I 645-0 REGION I CS 970 BROAD 'STREET d NEWARK. NEW JERSEY 07102

~ALIIS I

AUG 10 )972 Niagara Hohavk Power Corporation Docket Ho. 50-220 Attention: tfr. F. J. Schneider Vice President ' Operations 300 Erie Boulevard Hest Syracuse, Hev York 13202 GentleIIIen'hank you for your letter informing us oi the action you have taken or the program you intend to pursue in response to our letter of June 22, 1972, relating to "Ilail Thicknesses of Nucle'ar Service Valves."

The results and corrective actions vill be reviewed during subsequent inspections of your facility.

Your cooperation Mth us is appreciated.

Sincerely.yours, James P. O'Reilly Director cc: Hr. P. A. 3urt, General Superintendent bcc: RO Files DR Central Files PDR Local PDR HSXC DTXE

NIAGARA MOHAWK POWER CORPORATION NIAGARA

~ MOHAWK 3DD ERIE BOULEVARD WEST SYRACUSE, N. Y. IS202

~ " - - July* 21, 1972

. United States Atomic Energy Commission Division of Compliance,'egion I Attention: Mr. James P. O'Reilly Director 970 Broad Street Newark, New Jersey 07102

Dear Mr. O'Reilly:

Re: Provisional Operating License: DPR-17 Docket No.: 50-220 In your letter of June 22, 1972, you requested that we advise you of our tb'* ~ 1l ~

plans and schedule for documentation of wall thickness on valves relating to nuclear safety within the reactor coolant pressure boundary.

The valves installed in the reactor coolant pressure boundary at Nine Mile

, Point Nuclear Station, Unit 81, as defined in'subsection 50;55 (Codes and Standards) of 10 CFR 50, were designed and purchased under ASA B-31.1, B-16,5-1961, MSS-SP-66 and ASME Sections III and VIII. Those codes", at

,tJ>at ti~e,.did not require documentation of valve wall thickness 'although valve manufacturer was required to design and- cast the valve in

'"'the, accordance with the applicable code.

A comprehensive. review of our records indicates that documentation of valve wall thickness was not included in the manufacturing records. furnished to Nine Wile Point, Unit Itl.

In light of the above information, a program to obtain documentation of wall thickness of these valve bodies is being instituted.

The documentation of wall thickness of the affected valves will be the result of ultrasonic measurements of wall thickness, with comparison,to specified minimum wall thickness.

0

</fr.~ James P. O'Reilly, Director Page 2 Division of Compliance The ultrasonic measurement technique will be demonstrated to have a maximum error in repeatability and accuracy of not 'more than 2~a and documented against a machine test block of the .appropriate. material and minimum wall thickness.

Minimum wall thickness documentation using the above technique will be accomplished over a three year period commencing with Spring 1973 annual outage. Approximately 26 valves can be documented during each annual outage resulting in complete documentation .of the approximately 72 valves...

in three years.

Very truly yours, F, J. Schneider Vice President - Operations FJS:pw