We should consider the radiation and toxic material hazards in transit, in manufacturing, and in operation of nuclear energy installations.
There are well-known hazards and established safety protocols for the transport of radioactive materials and reactor components, e.g. new and spent fuel elements. We are fortunate in South Australia, because we have the potential to develop secure processing and manufacturing facilities at Woomera and at Whyalla. These centres are close to the uranium mines snd are interconnectd by an existing sealed highway and by a railway. There is no need to transport radioactive materials or components through centres of population. Whyalla has a 75ft. deep port anchorage, suitable for the forwarding and receipt of materials, components and reactors, to and from Australian and international locations.
Some of the raw materials which are processed in the nuclear industry, e.g. beryllia, uranium, thorium, cesium etc., are moderately radioactive. Low-energy alpha particles (helium ions) and beta particles (electrons) are unable to penetrate the skin. As is the case with asbestos dust, they are harmless except when ingested. Some radioactive materials emit neutrons or high-energy gamma rays, which are able to penetrate deeply into the body, may damage body tissues, and so require the use of radiation-absorbing screens.
It is essential that persons who work in the industry are adequately and appropriately protected in each potentially-hazardous situation, and are monitored to detect harmful excposure to radiation.
There have been only three significant recorded accidents in commercial nuclear reactors. This a much better record than may be claimed by the oil, gas and coal energy industries.
The Three Mile Island reactor developed a minor leak of radioactive cooling water from a cracked pipe into a containment pond, with no harmful radiation exposure to site personnel or to members of the general public. The Cherbonyl explosion, in an obsolete design, was the result of unauthorised high level testing during commissioning, causing total loss of cooling water, which rendered the graphite moderators transparent to neutrons and therefore ineffective. The Fukishima reactor, also of obsolete design and scheduled for de-commissioning 2 years before the accident, survived the earthquake (as it was designed to do) but suffered a loss of cooling water when the unprecendently-high tsunami flooded the coolant-pump system's emergency generators in the basement. This resulted in thermal runaway, but unlike Chernobyl, there was a release of radioactive material with no loss of life.
Generation IV nuclear reactors are intrinsically-safe by design - an increase in operating temperature results in a reduction in activity, so that thermal runaway is impossible. They do not rely upon pumped coolants. There are multiple redundant safety systems. The reactor shell is typically constructed of 20cm thick steel and is designed to contain the radioactive fuel in the highly unlikely event of a "meltdown".
In the case of thorium-fuelled reactors, activity requires an external source of neutrons and is readily controllable. Thorium is mildly radioactive. Unlike uranium, no enrichment of the fuel is required. In a thorium-fuelled reactor, almost 100% of the fuel is consumed. Thorium is fissile but not fertile - it can never produce excess neutrons, to produce a chain reaction. Neither thorium, nor the products of a thorium-fuelled nuclear reactor, are usable for weapons production.