A nuclear alternative - Thorium

A nuclear alternative
11 Dec, 2011 
CanberraTimes


Thorium Nuclear Power
http://nuke6.blogspot.com/2011/10/thorium-nuclear-power.html

In the wake of Fukushima, advocates of thorium reactors claim their time has come, says MICHAEL INMAN
NUCLEAR power. The mere mention of it evokes an emotion. But match the phrase with names such as Fukushima or Chernobyl and impassioned division will follow.

Since the disaster in Fukushima earlier this year, many countries are reassessing their nuclear programs.

In Germany, the government committed to shut 17 nuclear power plants by 2022.

Domestically, a renewed push to sell uranium to India is the subject of intense debate.

Passionate opponents of nuclear power claim the process is unsafe, produces toxic waste and is linked to the spread of weapons of mass destruction.

Meanwhile, supporters claim low emissions and new technology make nuclear's baseload energy capabilities the best option in the fight against climate change.

But what if there was a material capable of providing relatively safe and cheap nuclear power, without the risk of increasing nuclear weapons or toxic waste?

That's what a small but candid group of thorium advocates have been trying to tell the world in recent months.

But what is thorium?

Thorium is a natural radioactive chemical element that can be used to fuel a nuclear reactor.

It is estimated to be about three to five times more abundant than the current nuclear fuel of choice, uranium.

India, China, Japan, US and Russia are all undertaking investments in thorium fuel cycle technology, with intensified interest since Fukushima.

Thorium champions claim the world can have safe, baseload nuclear power by swapping the radioactive metal for uranium.

Supporters claim thorium technology is a lower risk than uranium reactors, produces considerably less waste and does not have the capacity to produce weapons.

And Australia, with an abundant supply of the metal, is well-placed to cash in on a future thorium rush.

Australia is believed to have the largest deposits of thorium in the world.

Geoscience Australia estimates Australia has about 474,000 tonnes - about 20percent - of the world's thorium resources.

Geoscience Australia commodity specialist Yanis Miezitis says the largest deposits are found in Western Australia, Northern Territory and Victoria.

Despite the easily accessed thorium resource, there are no large-scale commercial mining operations exploiting thorium.

Miezitis says this is because there is no large-scale commercial demand for thorium because there are no commercial-scale, thorium-fuelled nuclear reactors in the world.

However, that might all be about to change.

India looks likely to commence building a 300 megawatt advanced heavy-water technical demonstration reactor within the next 18 months.

An Australian and Czech Republic consortium last month unveiled plans for the development of a thorium-fuelled molten salt reactor, to be based in Prague, from next year.

Consortium spokesman Phil Joyce says preparatory work on the functioning prototype will be finalised early next year, with development to cost about $300 million.

Joyce says the consortium is pursuing thorium, rather than uranium, because it's less risky and produces less waste.

''Thorium is a non-fission material which means that it can't experience meltdown,'' he says.

''It took the Fukushima disaster to raise awareness and create an understanding of the urgency which exists in finding a safe alternative for base-load power.

''The time for planning and building thorium fuelled base-load energy plants has come and we are looking forward to developing the first working model that will be connected to the grid.''

Joyce says advances in reactor technology demonstrate that thorium-fuelled reactors are much safer than uranium and do not produce waste that can be used in weapons. He claims thorium is also efficient in its energy production, with one metric tonne of thorium creating the same amount of energy as 200 metric tonnes of uranium or 3.5 million metric tonnes of coal.

''Several European countries are moving to de-commission their nuclear powered generators, and the world is looking for more sustainable and safer, cleaner energy options. Investments in renewable technologies can only go so far in meeting the world's energy needs.

''We believe that attention should be shifted to thorium to replace the world's reliance on uranium and coal,'' he said.

But is thorium really the magic bullet that makes nuclear power palatable to the world?

Australian National University nuclear physicist Professor George Dracoulis says no.

Dracoulis admits thorium possesses many advantages over uranium, but also has inherent problems.

''People present thorium as if it's something magic. It's not, but it does have advantages.

''One advantage is that it doesn't produce as much long-life waste, although it actually produces more radioactive waste.

''A second advantage, which is only one of perception, is that thorium doesn't produce plutonium, a weapons material.

''So the argument is, you can't use [thorium] to make weapons but that's not true, it's more difficult but it can be used to make weapons.''

Dracoulis says a large problem with thorium is that it is not a fissile material, meaning it must be processed before the nuclear reaction takes place.

This is a more elaborate process, requiring specialist reactors.

Safety is also a key point pushed by thorium fans, but Dracoulis says this is also partially true.

''It doesn't have the potential to cause a Fukushima-type disaster, but that's because of the reactor, not because of the thorium.

''It's not the material that's safer, it's the way it's processed.''

With some estimates that the world's electricity demand will double by 2030, thorium could still play a role in future energy production.

But this may be in the longer term, according to RMIT nuclear expert Jiyuan Tu.

With energy demands skyrocketing in the short term, Tu says current nuclear stations need to begin developing new reactors, such as those fuelled by thorium.

The development of more sophisticated reactors calls upon radical new designs, moving away from the outdated generation II reactors, such as those at Fukushima.

The new reactors replace water with graphite, helium, sodium and lead to moderate and cool the core.

As a result, generation IV reactors will be more efficient, safer and produce less waste.

Still in the design phase, generation IV reactors are decades from becoming commercially available.

In the short term, Tu says current generation II and III reactors are being upgraded for safety.

With the nuclear industry in a massive state of flux, Tu says it is hard to predict where thorium will sit in the new order.