August 05, 1991

Article at Reuters

Australian-made ceramic offers safe storage of atomic waste

Synroc: The thin-walled vessel (left) is filled with a granulated waste form powder that is subsequently compressed into a solid mass by hot isostatic pressing

By Wilson da Silva

SYDNEY – Australian scientists believe they have found the answer to one of the biggest problems of nuclear power – how to dispose of radioactive waste safely, and for good.

The waste that nuclear power stations produce stays lethal for thousands of years after burial and eventually, inevitably, leaks out.

Now a material invented at the Australian National University (ANU) in Canberra, and developed by the Australian Nuclear Science and Technology Organisation (ANSTO), may ensure waste stays safely locked away in the ground for millions of years.

Called Synroc, for synthetic rock, it is an advanced ceramic which, when fused with radioactive waste, locks the waste inside the rock’s crystalline structure, its developers say.

A five kg (11 lb) chunk of chemically inactive Synroc is all that is left after 100 litres (22 gallons) of highly dangerous radioactive liquid waste is processed.

Four big Australian companies last year formed a consortium to study its application and marketing.

The partners are mining giants CRA Ltd and Western Mining Corp, conglomerate Broken Hill Pty Co Ltd and uranium miner Energy Resources of Australia Ltd, along with the ANSTO and the ANU.

“It is regarded around the world as potentially superior for the long-term disposal of waste,” said consortium chairman George Littlewood, a vice-president of CRA. “It’s a very, very big industry. We’ve got to the point where we’re saying, ‘this is worth a much closer look’,” he said.

About 97 per cent of spent nuclear fuel can be recycled but mined uranium is so inexpensive now that operators of the world’s 500 nuclear power reactors prefer to use it and then store the waste.

As uranium becomes scarce over the next few years, however, 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.

It is the remaining three per cent of spent fuel which cannot be used that the partners believe will give Synroc an edge.

“Anyone who plans to get into this business has to take a long-term view,” said ANSTO advanced materials director Dr Adam Jostsons. “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 becoming leaders in nuclear reprocessing. They have gazed into the future of atomic power and seen the advantages of getting a foot in the door early.

Traditionally, waste has been blended with glass, placed in metal canisters and stored. Latent radiation keeps the glass hot for some 50 years, so the waste must be monitored until it cools, and then buried permanently underground.

Groundwater slowly breaks down the canisters, finally exposing their contents.

Synroc resists leaching, even at high temperatures deep below the surface. This means waste can be buried four km (2.5 miles) deep, eight times more than current methods allow, at depths where rock is more stable and waste less likely to reach the surface.

After a year and A$500,000 (US$388,000), the consortium committed 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 tonnes of spent fuel a year – about 10 per cent of the world total – would generate revenue of more than A$1 billion (US$775 million) a year.

It would cost A$6 to A$10 billion (US$4.65 to US$7.75 billion) and employ 10,000 people in construction and 3,000 staff 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,” said Jostsons, chairman of the study’s first phase.

When the Labor Party won office in 1983 it banned development of new uranium mines and disallowed nuclear reprocessing in Australia.

Recent government and party reports have urged Australia – which has 30 per cent of the world’s uranium reserves but only 10 per cent of the world market – to allow more mines, and to expand into reprocessing and nuclear waste management.