June 2, 2009

Experts Study Methods Of Nuclear Waste Burial

Researchers at the Aespoe Hard Rock Laboratory in Oskarshamn, Sweden, are working toward the goal of becoming the first country to bury nuclear waste miles below the Earth's surface.

The Swedish Nuclear Fuel and Waste Management Company (SKB) plans to chose a site for its final nuclear waste repository sometime this month.

"If all goes as planned, construction could begin in 2016 and the first canister could be deposited in the repository in 2022 or 2024," SKB spokesman Jimmy Larsson-Hagberg told AFP.

About 14 percent of the world's electricity comes from nuclear energy, but there is no permanent solution for disposing of spent nuclear fuel.

About 45 percent of electricity in Sweden comes from nuclear energy. According to AFP, two Swedish towns of Oskarshamn and Oesthammar both already have nuclear plants and are hoping to become home to repositories. Currently, about 80 percent of the population in the two towns supports those plans.

"Local acceptance is a must for SKB in its decision-making process," said SKB guide Kajsa Engholm.

"Currently, about 4,993 tons of nuclear waste is stored at a central interim storage facility (CLAB) in Oskarshamn. The facility has the capacity of holding up to 10,000 tons," said guide Britta Freudenthal.

It takes about 100,000 years for radioactivity of the waste to drop down to the level the uranium ore contained when it was mined. Supporters say this underscores the need for permanent storage solutions.

"We have had interim storage of spent fuel in Oskarshamn since 1985. People here want a final solution," said Lars Blomberg, a member of Oskarhamn's city council.

"We think of things from a geological perspective, where 100,000 years is nothing compared to 1.8 billion years," said SKB guide Engholm.

Sweden, Finland and France plan to have permanent repositories in place by 2030, said AFP.

In Sweden, experts hope to use copper-lined canisters weighing about 25 tons each to store two tons of nuclear waste.

A buffer of bentonite clay, a volcanic ash that when mixed with water swells to provide a watertight barrier and protect against earthquakes, is then injected to fill the hole in the rock, said AFP.

When the repository is full, it is filled with a mixture of bentonite and rock.

"The canisters are buried several meters apart so the rock can absorb the heat generated by the radioactive materials in each copper canister," said Engholm.

"The generations that created the waste have a responsibility to take care of it," Engholm said.


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