EFFORTS are afoot again in Congress to prepare the way for the reprocessing of nuclear wastes and for the associated recycle of the plutonium thus produced for use as fuel in existing types of reactors. The vehicle is an amendment to the Nuclear Regulatory Commission's authorization bill that would require the NRC to revive an exotic rule-making proceeding known familiarly as GESMO -- Generic Environmental Statement on Mixed Oxide Fuel.

The law provides that such a statement must be completed and a positive ruling made before the NRC may grant licenses for reprocessing and recycle. Work on it was begun in 1974 but was suspended by the NRC in 1977, in conformity with the president's decision to defer indefinitely reprocessing in the United States. This decision was taken primarily on economic grounds, supported by non-proliferation considerations. Since 1977, both arguments have become, if anything, more compelling.

For reprocessing to make economic sense, the value of the plutonium recovered must be greater than the costs of recovery. Plutonium's value in this context hinges on the cost and availability of the uranium fuel it would be replacing. But since 1977 the price of uranium has dropped sharply, as have projections of future needs for uranium fuel.

The economic argument is buttressed by the fact that the spread of reprocessing technology offers any nation direct access to weapons-usable plutonium. Thus the proliferation risks associated with a nuclear fuel cycle involving reprocessing and recycle are far greater than those of a cycle that never produces weapons-usable materials. Since 1977, Pakistan has vividly demonstrated the point.

The ultimate irony is that reprocessing and recycle do not make the task of disposing of nuclear wastes any easier. Though some types of wastes are reduced, the process produces additional types so that the waste disposal knot -- the one that must be untangled if nuclear power is to survive -- remains as intractable as ever.

The last thing nuclear power needs now is a congressional directive that will pitch the NRC into three or four years of bootless debate over the pros and cons of reprocessing while urgent safety, health and waste disposal issues get shortchanged. The right approach for those who favor nuclear power is not to keep beating this dead horse, but to turn their attention to efforts to bring about a long overdue nuclear waste disposal program -- one that does not involve reprocessing.