The most urgent need at the Savannah River Site in terms of protecting the public, workers and the environment is to end the storage of liquid radioactive waste in aging steel tanks as soon as feasible. This waste is the most significant risk for the site and is the key part of the accelerated cleanup effort.

And yet, a safe and logical path forward to achieve that end has been meeting substantial opposition and legal challenges.

To recap briefly, there were 51 tanks at SRS holding liquid radioactive waste left over from making nuclear weapons material. This waste, depending on its radioactive form, was to be solidified either through the Defense Waste Processing Facility and shipped to a federal repository as glass, or through the Saltstone facility and disposed of on-site as hardened cement in concrete vaults.

For many years now, the Department of Energy has recognized that there would be some waste left in the storage tanks after technically and economically practical methods have been used to empty and clean them. In planning final tank closures, the Energy Department decided to have as much waste removed as possible and then fill the tank with the proper chemical and physical formulation of grout (cement), based on a scientific analysis of the residual material. Two tanks were closed in this manner at SRS in 1997.

The closures were acceptable to the Defense Nuclear Facilities Safety Board, the S.C. Department of Health and Environmental Control, the federal Environmental Protection Agency and, in an advisory capacity, the Nuclear Regulatory Commission. The regulatory agencies, and the state of South Carolina, all agree that the approach is sound and can be done safely.

A lawsuit nevertheless challenged this general approach and stalled the cleanup. Apparently the opposition is motivated by a vague notion that the closure method would leave more waste in the state than anticipated. If the challenge ultimately prevails, emptying the tanks will take about 23 years longer than necessary, cost an additional $16 billion and expose workers, the environment and the public to an unnecessary risk of leakage and occupational radiation exposure. This cannot be what any environmentalist wants.

Fortunately, Sen. Lindsey Graham proposed an amendment to the Defense authorization bill that would permit the accelerated cleanup. Now a House-Senate conference committee will work out differences between the Senate bill and the House bill, which did not contain the Graham amendment. Nothing could be more important to the state in terms of SRS cleanup than passage of that amendment.

The technology and application of grouting these tanks have been intensely reviewed by both the Nuclear Regulatory Commission and Savannah River National Laboratory and are well-established. Under heavy scrutiny, two tank closures using this method have succeeded. The risk is reduced, and cleanup greatly accelerated.

There is simply no good reason not to support this approach.

Dr. Wood is chairwoman of Citizens for Nuclear Technology Awareness.