Nuclear Power Offers an Abundant Supply of Low-Carbon Energy. But What to Do With the Deadly Radioactive Waste?

At 11:30 a.m., the crew of oil workers used a wire cable to lower a 30-inch (80-centimeter)-long, 8-inch (20-centimeter)-wide 140-pound (64-kilogram) canister — filled with steel rather than radioactive waste — down a previously drilled borehole. Then, using a tool called a “tractor” invented by the industry to reach horizontally into mile-deep oil reservoirs, they pushed it 400 feet (120 meters) farther away from the borehole through the rock.

Five hours later, the crew used the tractor to relocate and collect the canister, attach it to the cable and pull it back to the surface — to the cheers of the workers. Until then, few people in the nuclear industry believed this could be done.

By avoiding the need to excavate large, expensive tunnels to store waste below ground, the Deep Isolation team believes it has found a solution to one of the world’s most intractable environmental problems — how to permanently dispose of and potentially retrieve the hundreds of thousands of tons of nuclear waste presently being stored at nuclear power plants and research and military stations around the world.

“We showed it could be done,” Elizabeth Muller says. “Horizontal, directional drilling has come a long way recently. This is now an off-the-shelf technology. Using larger canisters, we think about 300 boreholes with tunnels up to 2 miles (3 kilometers) long would be able to take much of the U.S.’s high-level nuclear waste. We think we can reduce by two-thirds the cost of permanent storage.”

“We are using a technique that’s been made cheap over the last 20 years,” says Richard Muller, who has worked in the shale gas industry. “We realized we could put together the oil and nuclear technologies. One offered the solution to the other. These capsules can be lowered deep down, far deeper than anyone has proposed, and stored underneath a billion tons of rock so none of the radiation gets out.”

Great Stockpiles
The dilemma of how to manage nuclear waste — radioactive materials routinely produced in large quantities at every stage of nuclear power production, from uranium mining and enrichment to reactor operation and the reprocessing of spent fuel — has taxed the industry, academics and governments for decades. Along with accidents, it has been a major reason for continuing public opposition to the industry’s further expansion despite substantial interest in nuclear power’s status as a low-carbon power source that can help mitigate climate change.

In 80-odd years of nuclear power, in which more than 450 commercial reactors, many experimental stations and tens of thousands of nuclear warheads have been built, great stockpiles of different levels of waste have accumulated.

Depending on how countries classify waste, only about 0.2–3% by volume is high-level waste, according to the World Nuclear Association, a London-based industry group that promotes nuclear power. Mostly derived from civil reactor fuel, this is some of the most dangerous material known on Earth, remaining radioactive for tens of thousands of years. It requires cooling and shielding indefinitely and contains 95% of the radioactivity related to nuclear power generation.

A further 7% or so by volume, known as intermediate waste, is made up of things like reactor components and graphite from reactor cores. This is also highly dangerous, but it can be stored in special canisters because it does not generate much heat.

The rest is made up of vast quantities of what is called low-level and very low level waste. This comprises scrap metal, paper, plastics, building materials and everything else radioactive involved in the operation and dismantling of nuclear facilities.

The consensus is that around 22,000 cubic meters (29,000 cubic yards) of solid high-level waste has accumulated in temporary storage but not been disposed of (moved to permanent storage) in 14 western countries, along with unknown amounts in China, Russia and at military stations. A further 460,000 cubic meters (600,000 cubic yards) of intermediate waste is being stored, and about 3.5 million cubic meters (4.6 million cubic yards) of low-level waste. Some 34,000 cubic meters (44,000 cubic yards) of new high-level and intermediate waste is generated each year by operating civil reactors, says another nuclear industry group, the World Nuclear Association (WNA).

The U.S., with 59 nuclear power plants comprising 97 working civil reactors each generating at least several tons of high-level waste per year, has around 90,000 metric tons (99,000 tons) of high-level waste awaiting permanent disposal, according to the U.S. Government Accountability Office. Although it’s impossible to come up with a global total because of differences in how quantities are measured and reported, and with some inventories kept secret, other countries harbor significant amounts of waste as well.

Many Ideas
In the early days of nuclear power, waste of any sort was barely considered. British, U.S. and Russian authorities, among others, dumped nuclear waste, including more than 150,000 metric tons (160,000 tons) of low-level waste at sea or in rivers. Since then, billions of dollars have been spent trying to identify how best to reduce the amount produced and then store it for what may be eternity.

Many ideas have been investigated, but most have been rejected as impractical, too expensive or ecologically unacceptable. They include shooting it into space; isolating it in synthetic rock; burying it in ice sheets; dumping it on the world’s most isolated islands; and dropping it to the bottom of the world’s deepest oceanic trenches.

Vertical boreholes up to 5,000 meters (16,000 feet) deep have also been proposed, and this option is said by some scientists to be promising. But there have been doubts because it is likely to be near impossible to retrieve waste from vertical boreholes.

Two scientific developments excite nuclear scientists. One is to build a new generation of advanced fast neutron reactors, which would use the high-level waste as fuel. This slowly emerging “Generation IV” nuclear power program is billed by the industry as safer and more efficient. But even though such reactors can reduce the degree of hazard the waste poses, they don’t solve the issue entirely.

John Vidal was environment editor of the Guardian for 27 years. This article is published courtesy of Ensia.