United States Nuclear Regulatory Commission - Protecting People and the Environment

CONVAL INC.
265 FIELD ROAD, PO. BOX 1049, SOMERS, CT 06071
PHONE 860-749-0761 FAX 860-763-3557

May23, 2001

United States Nuclear Regulatory Commission
Document Control Desk
Washington, DC 20555
Fax: (301)816-5151

Subject: 10CFR-PaRT 21, Notification of Potential Safety Related Noncompliance Deviation

Dear Commissioners:

This letter serves to notify the Commission of a potential safety related noncompliance deviation in a basic component as defined in 10CFR-Part 21. The noncompliance involves flow coefficient values (Cv) of 366 valves of two body styles supplied over the course of 15 years to two nuclear power plants in the United States.

The breakdown is as follows:

GPU, Oyster Creek 122 Qty. �" Angle Body Ball Check Valves
Application: Charging Water Riser Isolation

Niagara Mohawk, Nine Mile Point Unit 1 114 Qty. �" Angle Pattern Ball Check Valves
Application: Charging Water Riser Isolation
130 Qty. �" Tee Pattern Ball Check Valves
Application: SCRAM Discharge Riser Isolation

Information was developed that led to an engineering investigation and the May 21, 2001 report by Conval's Quality Assurance Manager, Howard Smith II of this potential safety related noncompliance deviation.

The procurement document specifications for Niagara Mohawk, Nine Mile Point Unit 1 defined a Cv requirement of 3.5 for both the Angle and Tee Pattern Ball Check Valves. The procurement document specifications for GPU, Oyster Creek specified a Cv of 6 for the Angle Pattern Ball Check Valves.

Preliminary laboratory test reports generated during Conval's recent engineering investigation revealed actual Cv values of both valve styles to be below 1.5, significantly lower than those required by the procurement documents.

While there are no indications that the valves will mechanically malfunction, the fluid flow rates permitted in the forward direction will be below those anticipated in the procurement document specifications and, therefore, may constitute a safety related issue according to the intended use of the valves.

There are no noncorforming parts affecting the operation of the valves. The lower Cv values are a consequence of the internal geometry of these Conval valve designs. If requested, Conval's Engineering Manager, David Boyden will propose a retrofit of parts which, upon user acceptance, could be implemented within 4 weeks following user approval. The changes would significantly increase the flow capacity of the affected valves.

The two (2) nuclear plants affected have been verbally notified of this potential safety related noncompliance deviation.

If you have any questions or need additional information concerning this notification, please contact me directly.

Very truly yours,

CONVAL INC.

Donald L Curtin
President

Cc:
C. Siver, Chairman, CEO, Conval
F. Siver, Vice President, Conval
D. Williams, Vice President Finance, Conval
M. Hendrick, Vice President Sales and Marketing, Conval
H. Smith II, Quality Assurance Manager, Conval
D. Boyden, Engineering Manager, Conval
I. Makuch, Nuclear Accounts Representative, Conval

CLAMPSEAL VALVES

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