WHY ARE WE WORRIED ABOUT NUCLEAR PROLIFERATION?
Weaponisation of civil nuclear energy programmes
After the first nuclear reactor was built by Fermi in December 1942 at the University of Chicago, the United States successfully weaponised Chicago Pile 1 within just 3 years, exploding a uranium nuclear weapon over Hiroshima in August 1945. Nuclear weapons proliferation is a serious concern.
One third of the 32 countries having civil nuclear energy programmes have weaponised them. Ten countries have developed nuclear weapons: the United States, Russia, Britain, France, China, India, Pakistan, Israel, South Africa and North Korea. Iran may soon follow. South Africa unilaterally disarmed itself in 1991, the only country ever to have done so. The balance of probability is that one-in-three states acquiring nuclear energy technology for the first time will probably weaponize. By the same token there is only a 10% probability that a nuclear weapon state will voluntarily disarm.
Nuclear weapons proliferation has serious implications for the Middle East where there is serious interest in developing nuclear energy coupled with historic political instability.
Is there an alternative?
Although no nuclear technology is completely proliferation-proof, a new fourth generation of proliferation-resistant reactor technologies powered by thorium rather than uranium nuclear fuels are at present being contemplated for use in developing states.
From a proliferation resistance standpoint, thorium reactors have two major advantages: they produce 80% less plutonium than uranium reactors, and the plutonium is far more difficult to weaponise. In theory a 1 GWe nuclear power station fuelled with a Radkowsky thorium core produces only around 48 kilograms of plutonium annually, compared with 250 kilograms of plutonium discharged from a conventional uranium-235 fuelled reactor.
Plutonium from a Radkowsky thorium core also contains a high proportion of plutonium-238 and plutonium-240 contaminants, making it unsuitable for military nuclear weapons use for technical reasons. The minimum critical mass of RTR plutonium needed to produce a weapon is about 50% larger than for civilian PWR reactor plutonium, meaning that more plutonium is needed to make a viable nuclear bomb.