By Wilson da Silva
SYDNEY, Australia: Scientists believe they have found the answer to one of the biggest problems of nuclear power - how to dispose of radioactive waste safely and permanently.
The waste produced by nuclear power stations remains lethal for thousands of years after it is buried and eventually, inevitably, leaks out.
Now a material invented at the Australian National University in Canberra and developed by the Australian Nuclear Science & Technology Organization may ensure that waste stays safely locked away in the ground for millions of years.
Called Synroc (for synthetic rock), it is an advanced ceramic. When fused with radioactive waste, it locks the waste inside its crystalline structure, its developers say.
An 11-pound chunk of chemically inactive Synroc is all that is left after 22 gallons of highly dangerous radioactive liquid waste is processed.
About 97% of spent nuclear fuel can be recycled but mined uranium is so inexpensive at present that operators of the world’s 500 nuclear power reactors prefer to use it and then store the waste.
As uranium becomes scarcer and existing reserves are exhausted by the mid-21st century, uranium prices are likely to soar and nuclear plants worth billions of dollars will be forced to recycle waste or shut down.
‘‘Anyone who plans to get into this business has to take a long-term view,’’ ANSTO advanced materials director Adam Jostsons says. ‘‘Nuclear facilities take 10 years to build and by then you don’t know what the uranium supply situation will be like.
‘‘In the long term, it’s more sensible to reprocess spent fuel than to store it indefinitely.’’
France, Britain and Japan have spent billions of dollars becoming leaders in nuclear reprocessing.
The remaining 3% of spent fuel that cannot be reused will still give Synroc a niche, the partners believe.
Four big Australian companies last year formed a consortium to study its application and marketing.
The partners are mining firms CRA Ltd., Western Mining Corp. and Energy Resources of Australia Ltd., plus conglomerate Broken Hill Pty. Co. Ltd., ANSTO and the ANU.
Consortium chairman George Littlewood, a vice-president of CRA, says: ‘‘It’s a very, very big industry. We’ve got to the point where we’re saying, ‘This is worth a much closer look.’ ‘‘
Synroc resists leaching, even at high temperatures deep below the surface. Waste could be buried 2.5 miles down, eight times deeper than current methods allow, at levels where rock is more stable and waste less likely to return to the surface.
After a year and hundreds of thousands of dollars spent, the consortium commited itself in March to a second phase of study.
It has begun talks with the Australian government and is also talking to potential clients and partners overseas.
Ideally, the group would like to build a recycling and Synroc plant, in Australia or overseas, and offer a permanent site for the world’s nuclear waste.
The potential market is huge. The companies say a plant handling 1,000 tons of spent fuel a year - about 10% of the world total - would generate revenue of more than US$775 million (C$890 million) annually.
It would cost US$4.65 billion to US$7.75 billion and employ 10,000 people in construction and 3,000 to operate it.
Sparsely populated Australia has many geologically stable sites suitable for such a facility but it would need widespread support.
‘‘You can’t afford to get caught up in endless public relations battles. You have to work openly and carry the public with you,’’ says Jostsons, chairman of the study’s first phase.
When the Labor Party won office in 1983, it banned development of new uranium mines and nuclear reprocessing in Australia.
Recent government and party reports have urged Australia, which has 30% of the world’s uranium reserves but only 10% of the world market, to allow more mines and to expand into reprocessing and nuclear waste management.