- Nearly 200 Japanese police yesterday raided the offices
of the company operating a uranium processing plant where the country's
worst nuclear accident exposed more than 50 people to radiation last week.
Police investigations suggest that slipshod safety management, disregard
for regulations and poor worker training may all have contributed to the
- They have discovered that workers used an "illegal
operations manual" in preference to the proper manual, the specialist
news agency NucNet News reported yesterday.
- Citing the Japan Atomic Industrial Forum as its source,
NucNet News said that one of the workers exposed to radiation told police
that even the unofficial manual had been ignored at the time of the accident.
- It appears that the workers did not even understand what
the world "criticality" meant. The accident occurred when three
workers poured uranyl nitrate solution into a sedimentation tank. Even
the unauthorised manual required them to pour it first into an intermediary
tank to prevent a critical mass of uranium being put together.
- One worker told police: "We talked, and decided
to finish the work quicker."
- An official from JCO, the company which operated the
plant, confirmed that the workers were not educated about the dangers of
criticality, had never before worked with uranium as highly-enriched as
the fissile isotope uranium-235 (18.8 per cent) and that none of the three
was wearing a film badge to record radiation exposure.
- The Science and Technology Agency has decided to revoke
JCO's operating licence because of the seriousness of the accident, according
to Japanese media reports.