Tuesday, 30 January, 2007

by Will Fisher
The Courier Mail

WITH debate building about nuclear energy as an alternative, greenhouse-friendly power source, Australia has a new nuclear reactor - and it's already up and running.

The new OPAL reactor replaces the old HIFAR facility at Lucas Heights, south of Sydney, which will be officially decommissioned today.

OPAL is loaded with uranium and will produce 20 megawatts of power - enough for a small town - when it's fully operational.

But it's not the power plant Prime Minister John Howard said he'd be happy to have in his backyard while recently arguing the merits of nuclear energy.

The OPAL reactor will be used for medical, industrial and research purposes, rather than cooking your dinner or running your air-conditioner.

Its cooling water just isn't hot enough to drive a steam turbine and generate electricity.

"I suppose you could have a shower with it but that's about all," said Ron Cameron, director of operations at the Lucas Heights research station run by the Australian Nuclear Science and Technology Organisation (ANSTO).

So if it isn't powering our cities, what's Australia getting from this $350 million reactor?

Neutrons, according to ANSTO.

Neutrons are the key to nuclear fission - when a uranium atom splits in two, it releases a load of energy and it also releases two neutrons.

If these neutrons collide with another uranium atom, that atom splits as well, releasing another two neutrons, and so on, producing a chain reaction.

In a nuclear power station, it's the energy that's harvested. But in a research reactor such as OPAL, it's the neutrons.

"We have one of the most consistent neutron fluxes in the world. We have a very high reliability," Dr Cameron said.

That reliability has given ANSTO about 15 per cent of the world market for processing the silicon chips that go inside electronic items from mobile phones to supercomputers.

But whether it's for research or power, critics question the risks of running a nuclear reactor in Sydney's backyard - such as a meltdown which potentially releases radioactive contamination into the environment.

Dr Cameron said there was very little risk of that happening with OPAL because it operates at a low temperature.

But he admitted that over its 40-year life, OPAL will generate several cubic metres of high-level waste, which it intends to store in a remote location in the Northern Territory.