THE NOW-YOU-SEE-IT-now-you-don't congressional treatment of the funds for the Clinch River breeder reactor has led, at least for the time being, to a setting aside of the project. This was what President Carter had been urging for a variety of reasons. One of them was a desire to indicate to other nations now going forward with the plutonium-fueled and producing fast breeder that the United States, which wants a slowdown, if not an actual halt in the development of this particular technology, is itself willing to forego work on the plutonium breeder.

To be sure, this is more in the way of a gesture than a deprivation, since this country with its fossil fuels, uranium supply and well-developed light-water reactor technology does not stand in any especially urgent need of bringing the breeder reactor on line. But to say that is not to say it is an empty or unnecessary gesture: We can hardly hope to get the Europeans and the Japanese turned around on the question of a plutonium-cycle future if we ourselves are not even willing to step back from one project such as this one.

Still, no one should think that our pullback will have anything but a marginal impact on the relevant countries' thinking - if that. For what the United States must make the Japanese and the Euratom countries understand is that it is still far from obvious that the plutonium reactors are their best bet for the future. This is something quite different from persuading them that we are not headed down the breeder road ourselves. They know that. What they do not know is what their alternatives are.

This country, in the past, can hardly be said to have been helpful in that respect. For years, mindlessly, we promoted abroad the very technology we have now recognized as dangerous (plutonium is also a nuclear explosive). We oversold it. And now part of the American obligation is to undo some of the distortions of that oversell.

For example, you hear a lot from the Europeans and Japanese about the desirability of the plutonium breeder as a guarantor of their "energy independence" - something of acute importance to countries that have limited fossil fuels. Only now is it becoming evident in studies being done by scientists and economists on the subject that this notion of "energy independence" as a result of the plutonium breeder is a chimera: electricity being a considerably less efficient heating fuel than oil and gas, it would take an enormous supply of plutonium-generated electricity to do the job the Europeans and Japanese have in mind, putting that independence a very long way down the road indeed.

It is of course true about this - along with just about everything else to do with nuclear energy - is something you will get an argument on. But if any one thing is clear it is that the kind of pause for evaluation and reconsideration that President Carter is urging on the Europeans and the Japanese could not in itself represent any kind of dangerous, or even noticeable, loss of time against the acquisition of "energy independence."

A lot of people think the move is slow the rush to a plutonium economy is already doomed. Maybe it is and maybe it isn't. We do know this - that Jimmy Carter would be reckless and irresponsible not to try to create that breathing and thinking space in which to consider, with the Europeans and Japanese, what the alternatives are; to spell out our own economic and scientific worries about the course they are embarked on; to elaborate on what we are prepared to do to guarantee a flow of enriched uranium fuel to countries foregoing the breeder; and, if it turns out that plutonium is the wave of the future, to try to work out some international disciplines to make it less dangerous. No one can say whether the President will succeed. But a deferral of the Clinch River project will at least prevent his looking foolish while he tries.