The proposal passed easily through the house after years of debating the risks of nuclear waste, with 159 deputies voting in favour, three opposing and 37 members absent.

"The unanimity is important because this is such a far-reaching and important decision," said Leena Luhtanen, a deputy of Prime Minister Paavo Lipponen's Social Democratic Party.

Greenpeace, which has called for temporary storage of nuclear waste until an acceptable solution was found, called Friday's decision a dangerous one.

"It gives a dangerous message that this kind of method of storing nuclear waste is acceptable," said Harri Lammi, a Greenpeace nuclear campaigner in Helsinki. "Parliament did not spend enough time studying the safety issues."

The Finnish waste-disposal company Posiva is expected to begin researching possible sites in western Finland and plans to start building the deep waste dump in the year 2010.

But the dump needs a further construction permit from the government, and radioactive waste will not be deposited there until 2020 at the earliest.

If members of parliament have objections to the actual construction plans at a later date they will be able to raise the issue again.

The move comes at a time when countries across Europe are moving away from nuclear power, with public opinion increasingly opposed to both atomic energy and worried about radioactive waste disposal.

Even the Greens, junior partners in Finland's five-party coalition government and strongly opposed to nuclear power, voted for the proposal.

"The decision shows responsibility: we have four (nuclear) reactors that produce waste all the time. We decided not to continue the temporary storage forever," said Luhtanen.

A 1995 law forbids the export of nuclear waste, which up to the mid-1990s was shipped to Russia for reprocessing and storage.

The radioactive waste is expected to be buried underground at Olkiluoto in the town of Eurajoki on the west coast of Finland, next to the nuclear power plant there.

The Eurajoki authorities have already accepted the radioactive waste unit, which will bring the town up to 10 million Finnish markka ($1.48 million) annually - nearly 17,000 markka per capita - in real estate tax revenues.