United States Nuclear Regulatory Commission

Office of Public Affairs

Washington, DC 20555

Phone 301-415-8200 Fax 301-415-2234

Internet:opa@nrc.gov

No. 99-214 FOR IMMEDIATE RELEASE

(FRIDAY, OCTOBER 8, 1999)

NRC WILL STUDY JAPANESE ACCIDENT FOR

POSSIBLE SAFETY ENHANCEMENTS

In response to the President’s request, the Nuclear Regulatory Commission, in close

cooperation with other federal agencies, is working to learn more about the unfortunate

criticality accident that recently occurred at a nuclear fuel fabrication plant in Tokaimura, Japan,

to see whether lessons learned there might further improve the existing programs at

commercial fuel fabrication facilities in the United States. Thus far, as a result of the Tokaimura

event, NRC has not identified any safety concerns that would require immediate action. NRC

will continue to evaluate lessons learned from the Tokaimura event as they become available

and appropriate changes will be made, if and when information is identified that potentially

impacts the health and safety of plant workers or the public.

The Japanese government has accepted the President’s offer to send a small team to

Japan to learn first hand about the accident. NRC plans an in-depth review of the details

surrounding the event following the team’s return to determine whether further improvements in

the existing U.S. regulatory program would be prudent. NRC plans to issue an Information

Notice to alert our fuel facility licensees of the circumstances surrounding the accident and

acquaint our licensees with what the U.S. and Japanese governments are doing to address the

situation.

NRC has also been informed that the commercial nuclear fuel facilities are themselves

planning to conduct a self assessment of their criticality programs in light of what is known and

will become known about the Japanese event. Industry’s initiative is of course welcomed by

NRC, since periodic self-assessment is a necessary and important part of safety.

There has not been a criticality event at a commercial U.S. nuclear fuel facility in 35

years, but efforts are constantly underway to improve safety. To ensure prevention of such an

event, NRC has a very robust regulatory program, with a highly trained and experienced staff.

This program includes both licensing and inspection activities.

NRC performs detailed licensing reviews before a facility is granted a license and is

allowed to process nuclear material. These reviews include detailed analyses of the proposed

criticality safety programs to include the specific controls that are in place to prevent a criticality

for all new operations, as well as for significant modifications. Licensed designs must ensure

that safety controls are developed and implemented such that two unlikely and unrelated events

must occur before a criticality is possible. Licensees are required to report to NRC when any of

these criticality controls fail or are not available.
NRC regulations require criticality alarms in all fuel cycle facilities where nuclear material

is stored or processed and all employees are trained in emergency procedures. All of these

facilities are required to have an Emergency Plan which defines how the licensee will respond

to radiological events, such as a criticality, and these plans are exercised periodically. These

plans include the identification of all significant events that could conceivably occur at the site

and the development of recommendations for each event to be communicated to Federal, State

and local authorities.

Facilities that handle higher enriched uranium, similar to the type of material that was

being processed in Japan, have resident inspectors who work at the facility on a full time basis.

These facilities receive at least two criticality safety inspections a year, plus pre-startup

inspections for any new processes or for the restart of processes that have been shut down for

any extended period of time. NRC inspectors verify that the licensees have effectively

implemented regulatory safety requirements for the safe handling, storage, and processing of

licensed materials regarding criticality safety. NRC resident inspectors have been directed to

heighten focus on the implementation of the criticality safety programs at these facilities. In

addition, NRC conducts routine nuclear criticality safety inspections commensurate with safety

risk and licensee performance at all commercial fuel cycle facilities. All facilities have been

inspected this year.

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