Muhammad Rayan
2022-CH-35
Assignment No 1
Presented to:
Miss Sobia Anwar
Health and Safety
Incident:On September 1999 in Japan, three workers with no proper
qualification and training were preparing a small batch of fuel for an
experimental fast breeder reactor using a much more enriched
uranium for the first time under Japan Nuclear Fuel Conversion Co
(JCO). The work procedure was modified by the organization without
the permission of regulatory authorities. This eventually caused the
nuclear fission chain reaction to become self-sustaining and began to
emit intense gamma and neutron radiation. Although there were no
explosion, the criticality lasted for about 20 hours.
The three workers had, unfortunately, received full body
radiation dosage mainly from the neutron that was emitted, and two of
them passed away shortly after the accident occurred.
Analysis
What happened?
Uncontrolled nuclear fission chain reaction occurred causing
massive emission of gamma and neutron radiations.
How did it happened?
The workers were preparing fuel using large amount of
enriched uranium. Since uranium is a radioactive and highly unstable
element resulting in uncontrolled emission of gamma and neutron
radiations.
Why did it happened?
 The workers were not qualified enough to deal with radioactive
elements like uranium.
 Workers were unaware of the hazard of self-sustaining nuclear
fission chain reaction.
 The organization failed to train the workers properly
 Workers did not take any precautions about the procedure and
often do not use personal protective equipment (PPE)
 The regulatory authorities also failed to stop the organization in
modifying the procedure.
 The lack of proper control on the procedure enhanced the
likelihood of criticality.
Prevention: The organization should gave proper training to the workers.
 It should hire qualified workers.
 Organization should maintain a satisfactory and cooperative
environment for the workers.
 The workers should be given proper instructions and aware of the
hazards of uranium or any other radioactive element.
 The regulatory authorities should pickups a common procedure
followed by all the organizations.
 The authorities should have proper check and control over all the
organizations