Members of the House and Senate Appropriations Committees will work out in the next few weeks differences in their energy-funding bills. A relatively small, but significant difference between the bills is over money for continued research for advanced liquid metal reactors, so-called breeder reactors, which has so far cost $9 billion. At a time of supposed austerity in Washington, this program should be canceled.

After voting in favor of the breeder-reactor program last year, Sen. William Cohen made a positive change by joining Sen. George Mitchell recently in rejecting the nearly $100 million appropriation. The Senate, however, voted to table the amendment that would have killed the program. The House already had taken the more fiscally responsible step of rejecting it outright, with Reps. Olympia Snowe and Tom Andrews voting in the majority. The two houses are expected to reach an agreement on the issue in the next couple of weeks.

Killing the program now would save the country $2.9 billion over the next 15 years, according to Secretary of Energy Hazel O’Leary, who called the project incompatible with the U.S. interests abroad. Congress killed a similar project, called the Clinch River Breeder Reactor, in Tennessee in the early 1980s because of the uncertain future of the technology.

An argument for maintaining the research on advanced liquid metal reactors is that, theoretically, they will be able to use as fuel the abundance of plutonium in existence since the dismantling of nuclear weapons. Unfortunately, according to Charles Till, associate director of the Argonne National Laboratory, where much of the research is being conducted, what makes the system work as a burner of plutonium also allows it to become a breeder. Mr. Till told the Senate Energy and Natural Resources Committee last summer that scientists could convert such a reactor to a breeder in a matter of weeks. This potential is what caused much of the recent tension between the United States and North Korea, and what could allow other hostile nations to obtain nuclear weapons.

Though no one can predict the long-term future of energy sources for the United States, it’s a safe bet that new nuclear-energy plants are unlikely to come on line. Given the cost of the breeder program and the demand for funds in energy areas (conservation, for instance) that are more politically acceptable, Congress should pull the plug on this research.