Finland to bury nuclear waste

May 5, 2006

An unprepossessing tunnel entrance set in low forest on the western coast of Finland marks the probable final resting place of the country's most dangerous nuclear waste.

Finland is one of a handful of countries which has embarked on the journey towards a "final" waste solution.

Enter the 20ft-high, 16ft-wide Onkalo tunnel, and you would drive down a spiralling track which will eventually stretch 3miles through solid rock, reaching a depth of 1,600ft.

Investigators will be the first to go down the tunnel, aiming to demonstrate that the rock is structurally sound enough to proceed with the disposal of spent fuel rods containing plutonium and other unpleasant materials.

If they were to turn up a positive result, and if government agencies grant the necessary licences, the first canisters of spent fuel would begin rolling down the tunnel about 15 years from now.

It looks as if Finland is on course to become the first country in the world to entomb its most troublesome nuclear waste in a designated final resting place.

The Onkalo facility is run by the company Posiva, and the system it uses is a Swedish concept called KBS3, which Sweden's proposed repository would also implement.

The other country close to solving its problem, the US, is exploring a different technology at its Yucca Mountain site located in Nevada.

"The safety concept is based on so-called 'multiple barriers'," says Timo Aikas, Posiva's vice-president in charge of engineering.

"One barrier is of course the solid stable crystalline rock. The remaining barriers are engineered barriers, the most important of which is long corrosion-resistant copper canisters, inside which we put the actual fuel rods."

In this vision, the bottom of the Onkalo tunnel would sprout a grid of horizontal shafts.

Canisters containing the spent fuel rods would be deposited into holes in the bottom of each shaft.

The canisters would nest in a bed of bentonite clay, which swells when it absorbs water. This comes with twin benefits; cushioning the cargo from geological movement, and ensuring there are no voids where substantial quantities of water can penetrate, corroding the canisters and carrying away their radioactive contents. As each canister goes in, the tunnels would be filled up again with yet more clay and rock. By 2100, the repository would be complete, access routes would be filled and sealed.

Technology is only one part of the Finnish solution; the other vital component is finance.

"Our current cost estimate for this 'funeral' is about 3bn euros," says Timo Aikas.

Three billion euros is a significant sum of money. Is this another example, then, of the state having to pay vast sums to clean up a nuclear industry which has in the past generated profit for private ends?

The signs point in a different direction. The advent of commercial nuclear power to Finland in the late 1970s saw the establishment of a fund to pay for the eventual clean-up.

"Every year, we have re-calculated the fund based on the amount of spent fuel accumulated," says Timo Aikas, "and at the moment the fund is approximately 1.4bn euros."

The money has come from generating companies through a small levy on the price of nuclear electricity.

It is, perhaps, the sort of measure which current British leaders looking at a waste disposal facility bill in the region of 14bn euros would wish their predecessors had chosen to implement.

"When the site selection started in Finland, the nuclear industry said they would find the best geological site," says energy campaigner Kaisa Kosonen.

"And, eventually, they chose the site on sociological reasons, because eventually Eurajoki was the first municipality to say 'ok, we can take it', and there wasn't an active nuclear opposition in this area."

That lack of local opposition may be down to the fact that nuclear reactors have stood in the area for three decades, gaining acceptance for an industry which has maintained a good local safety record and brought employment.

"It boils down basically to trust," comments Timo Aikas.

"When you make a decision concerning this kind of thing, which takes us to 2100 when the final sealing takes place, there will always be uncertainty. So you have to have trust."

Kaisa Kosonen urges caution; the case for Onkalo, she says, is not proven.

"I would like to see much more research done and not having this hasty process," she says. "And I would not want this marketed as 'waste issue solved', because it's not."

But Timo Aikas believes his system and his team deserve the trust they have found in Eurajoki, and that Onkalo will prove as safe a resting place as can be found, barring any surprises with the local geology.

"Nuclear waste doesn't go away," he reflects.

"And if we just keep it in stores above ground we just push the problem to the next generation. It's much more responsible now to develop solutions on how to take care of it."