CHRONOLOGY -Mishaps at Japan nuclear facilities

[Thomas M Lashley <lashleyt@dteenergy.com>]

CHRONOLOGY -Mishaps at Japan nuclear facilities
Updated 6:05 AM ET September 30, 1999
TOKYO, Sept 30 (Reuters) - The following is a brief chronology of recent mishaps
at nuclear-related facilities in Japan.
Nuclear power is the source of about 30 percent of Japan's electricity and is
considered crucial by the Japanese government to meet the country's growing
energy needs.

- - - - December 8, 1995 - Massive leak of coolant at prototype fast-breeder
reactor Monju, located in western Japan. Although there was no radiation leak
outside the plant, operated by state-run Power Reactor and Nuclear Fuel
Development Corp (PNC), Monju remains shut and has yet to resume operations. No
official timetable has been set for its restart.

December 10, 1995 - Initial investigation reveals three tonnes of the sodium
coolant had leaked at Monju, pointing to a major accident.

March 11, 1997 - Fire at the PNC nuclear fuel reprocessing plant located at
Tokaimura, northeast of Tokyo. PNC reports fire at the nuclear waste treatment
facility under control, but explosion nine hours later exposes 37 staff to
radiation in Japan's worst nuclear accident.

Entire plant, which reprocesses about 12 percent of Japan's spent nuclear fuel,
is shut down and remains shut.

March 17, 1997 - PNC's uranium fuel production plant, also at Tokaimura, shut
down after false alarm warning that fuel reached critical mass -- the point at
which a nuclear reaction becomes self-sustaining.

April 15, 1997 - PNC says there was an accident the day before at the Fugen
advanced thermal reactor in western Japan which leaked radioactive tritium. Local
government officials say 11 workers were exposed to low levels of radiation.
Fugen ordered shut down by the government.

Fugen resumed operation in December 1997.

August 26, 1997 - Revelations emerge that a radioactive waste storage facility at
Tokaimura managed by PNC had leaked low-level radiation over a period of about 30
years. The radiation leaked from about 2,000 drums each containing 200 litres (53
gallons) of low-level radioactive waste produced by uranium processing.

July 12, 1999 - A 1.16 gigawatt commercial nuclear power reactor operated by
Japan Atomic Power Co plant was forced to shut after radioactive coolant water
leaked within the reactor container. It was one of the worst-ever water coolant
leaks in Japan. The No 2 reactor at the Tsuruga nuclear station in Fukui
prefecture, west of Tokyo, leaked 51 tonnes of primary cooling water before it
could be plugged.

The company hopes to resume operations of the reactor in January.

September 30, 1999 - Accident a uranium processing plant operated by private
company JCO Ltd in Tokaimura exposes three workers to radiation. Authorities
evacuate the vicinity and government officials say there may have been a
"criticality incident" causing radiation levels to race up 4,000 times higher
than normal. Criticality is the point at which a nuclear chain reaction becomes
self-sustaining, similar to what occurs inside a nuclear reactor.



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Note: Criticised for mismanagement of its various nuclear facilities, the
state-run PNC went through a sweeping government review and was relaunched as
Japan Nuclear Cycle Development Institute (JNC) in October 1, 1998.






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