NRC NEWS

 U.S. NUCLEAR REGULATORY COMMISSION 

 Office of Public Affairs Telephone: 301/415-8200

 Washington, DC 20555-001 E-mail: opa@nrc.gov 

 Web Site: http://www.nrc.gov/OPA

No. 03-112 September 4, 2003

NRC ISSUES BULLETIN ON POTENTIALLY DEFECTIVE VALVES

MANUFACTURED BY HUNT VALVE COMPANY

The Nuclear Regulatory Commission is requesting licensees who process, use, store, or

transport uranium hexafluoride (UF6) to verify that certain valves used on UF6 cylinders meet NRC

regulatory requirements and to remove potentially defective valves from service over the next 12

months. The NRC believes that there is no imminent safety concern that would necessitate immediate

replacement of these valves, because there have been no UF6 leaks reported due to the identified valve

problems.

The agency has issued a bulletin notifying licensees who use UF6 of potential problems with 1-

inch valves manufactured by the Hunt Valve Company of Salem, Ohio. The bulletin requires the

licensees to identify such valves in their possession and either replace them or determine through tests

that they comply with existing NRC regulations, NRC licenses and certificates of compliance, and

Department of Transportation regulations. Licensees are to ensure that UF6 cylinders with such valves

already installed are safely used during a transition period, not to exceed 12 months, and ensure that

only valves verified to be compliant are in use after the end of the transition period.

Where Hunt 1-inch valves are already installed on stored cylinders containing depleted UF6 and

the cylinders are not to be further processed or transported off site, replacement of the valves is not

being requested; instead, licensees are being asked to develop a sufficient safety justification for

planned continued use of the Hunt valves on these cylinders.

Although there have been no leaks of UF6 attributed to the problems cited in the bulletin, the

valves are an important part of the cylinder’s single containment boundary to prevent the release of

radioactive and chemically hazardous material to the workplace and environment or leakage of water

into the cylinder. 

The NRC will hold a public meeting about its concerns regarding Hunt Valves and the actions

specified in the bulletin. That meeting will take place September 16, from 9 a.m. to noon, in the NRC

auditorium at Two White Flint North, 11545 Rockville Pike, Rockville, Md.

In October 2002, the NRC notified licensees of two safety concerns relating to the Hunt valves:

cracked packing nuts and significant deficiencies in the company’s quality assurance program. On

March 24, the NRC notified licensees that several Hunt valves failed hydrostatic testing at pressures 
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required by NRC regulations but well above pressures expected during normal operating conditions or

potential accidents. 

Because of the deficiencies in Hunt’s quality assurance program, licensees are instructed not to

rely on any information provided by the manufacturer when determining whether the valves meet NRC

and Department of Transportation regulations.

Hunt has manufactured approximately 16,000 of the valves since production began in 1991. 

The text of the bulletin will be available on the NRC web site at http://www.nrc.gov/readingrm/doc-collections/gen-comm/bulletins .

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