Nuclear Hazards
Accidents
Three Mile Island
This 1979 meltdown of the uranium fuel in a nuclear power
station at Three Mile Island in Pennsylvania USA caused major changes in
nuclear safety management practices and led to a halt in the building of
nuclear power stations in the USA. Such a meltdown had, up until then,
been considered virtually impossible. A famous movie, The China Syndrome,
which was about the meltdown of fuel in a nuclear reactor, and which was
released shortly before the accident, had been described in Time magazine
as far fetched.
No one was directly killed at Three Mile Island but increased
levels of ionizing radiation resulted in an increased risk of cancer. The
actual number of cancers caused is impossible to determine. There is as
yet no way to directly connect a particular cancer to a particular ionizing
radiation exposure.
The meltdown occurred when a minor reactor malfunction
caused the temperature in the primary coolant to rise, automatically shutting
down the reactor. One of the relief valves failed to close and most of
the primary coolant drained away, leaving the reactor core at a very high
temperature. The uranium fuel melted and radioactive material was
released into the cooling water. The meltdown caused considerable public
concern and loss of confidence in the nuclear power industry.
Chernobyl
The Chernobyl nuclear disaster
in 1986 is an example of the unforgiving nature of nuclear energy.
A power surge, during a test to determine how long the turbines would spin
after a power loss, caused steam to lift the cover plate off the reactor,
and an intense fire spread fission products into the atmosphere. This accident
was caused by human error.
41 power plant employees and firemen died soon after the
accident, while another 134 emergency personnel experienced acute radiation
sickness and may eventually die as a result of their exposure to ionizing
radiation.
Childhood thyroid cancer increased 60 fold in the region
(Belarus) around Chernobyl.
Radiation related deformities occurred in babies of women
who were pregnant at the time of the disaster.
Among relocated people there has been a massive increase
in stress related illnesses such as heart disease and obesity.
Cancer from those exposed to relatively low doses of ionizing
radiation is not expected to be manifested until 20-30 years after the
disaster.
Research is continuing in order to determine the full
impact of the disaster on people and the environment.
There have been many other less-publicised
accidents in the nuclear industry including at Sellafield (formerly known
as Windscale) in the UK, Tsuruga in Japan, and in Australia.
Roxby Downs
Roxby Downs has had four major accidents
in its processing plant: a smelter explosion, a tailings dam leak, and
two fires.
The latest accident, in October
2001, was a fire involving the solvent extraction plant. This plant uses
a flammable solvent for extracting uranium from the acid leach solution.
The fire caused $30 million damage to equipment. A police-fire department
report on the fire has yet to be released.
More
information on Roxby
Beverley
Beverley has had a number of accidents.
The latest, in February 2002, being a burst pipe that released 62,000 litres
of acidic radioactive toxic liquid at its processing plant.
More
information on Beverley
Greater technical detail can be found on this topic by searching through
the listed briefing papers and education resources at
http://www.ccsa.asn.au/nic/.
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