Proposal for burying cold-war nuclear waste in concrete faces scrutiny.
Independent experts have finally been given the chance to comment on highly contentious plans for disposing of almost 100 million gallons of radioactive waste.
The waste was generated during the cold war when spent fuel rods from nuclear reactors were converted to weapons-grade plutonium. It is now being kept in massive tanks at Department of Energy sites in Idaho, South Carolina and Washington state.
The problem of its disposal has been a bone of bitter political contention for decades. Particularly rancorous is the issue of whether the energy department should have the power to reclassify certain waste so that it can deal with it more flexibly and cheaply. This power was successfully challenged by an environmental group, the Natural Resources Defense Council, in 2003.
The department regained that power this year in Idaho and South Carolina, when Congress's Armed Services Committee inserted a provision into the National Defense Authorization Act to make it legal. But under pressure, the committee conceded that 21 independent experts at the National Academy of Sciences should be allowed to assess the technical risks in the agency's proposed disposal plan.
The plan calls for various treatments for the contents of the storage tanks. Liquids that are less radioactive would be dealt with on-site. The radioactive salt cake would be extracted, processed and shipped to a long-term repository. Concrete would then be added to the highly radioactive sludge that has settled at the bottom of the tanks to dilute the radioactivity.
It is this last step, which critics call ‘disposal by dilution’, that the experts, who met on 7 March, are looking at. They will assess the long-term safety of the technique and will examine alternatives.
Environmentalists are angry that the energy department has regained freedom from rigorous oversight in nuclear-waste disposal. They hope that the panel will expose what they see as an inadequate clean-up and a lack of credibility.
Energy department spokesman Joe Davis denies the lack of credibility. “Many agree that this is the way to proceed,” he says, adding that the agency reviews reports from the National Academies and “takes their opinions and thoughts into account as we go about our work”.