Some days it's hard to find something good to worry about. On those bad days I usually worry about what to do tonight, or worse, tomorrow or next week and how best to avoid doing anything useful about it. That way lies despair. But other days it's easy to find something good to worry about, and this is one of the easy days. I'm worried about how to talk to the 120th Century -- a mere three or four hundred generations and 10,000 years away, after all -- and I am not alone. So is the Department of Energy, which has gone so far as to commission a report about it, "Communication Measures to Bridge Ten Millennia." I read about it in T.R. Reid's story on the front page of Sunday's Post, and it gave me something to brood about the rest of the day, and the next day too. Thus are the hours filled between the troubled midnight and the noon's repose, as the poet said.

The reason the Department of Energy wants to be able to communicate with Americans of the 120th Century is, basically, compassion. They want to warn them that one of the most enduring monuments of our high civilization, the only one that seems guaranteed to survive, is, well, toxic -- at least until 12,000 A.D. It is the waste from nuclear power plants and weapons -- the odd fuel cell, the obsolete warhead, the poisonous byproducts -- now piling up by the ton in temporary facilities here and there but awaiting entombment in a permanent underground dump, the precise location of which has yet to be decided because, as Rep. Morris K. Udall (D-Ariz.) put it, "Nobody wants the honor of having his state glow in the dark for the next 10,000 years." (Always thinking about their own limited constituencies, these congressmen, instead of the greatest good for the greatest number.)

You've got to say this for the Department of Energy: at least someone over there is thinking about it, and thinking that there will be a 120th Century, too, which is more than you can say for some of the present generation of high priests mumbling on about Armageddon, Sodom and Gomorrah, and the like. And speaking of priests, one of the more original recommendations of the "Human Interference Task Force" that produced the study is the creation of an "atomic priesthood" -- the new druids, as it were -- to pass the message along in ritual and romance. I like that idea. So does the task force, which favors the druids over "microsurgical intervention with the human molecular blueprint." Some of us, after all, are Christian Scientists and opposed to surgery, which has another strike against it: it hurts. But no right-thinking American is opposed to religion, and new ones are springing up all the time.

One of the newest is the cult of the semiotician, whose field is the way we communicate with one another, by sign and symbol and gesture, and what we mean by what we say and do. To the semiotician, everything is a form of communication and communication, naturally, is everything. Thus does the cult endure and its tribe increase. The new priestly caste, by the way, will consist of semioticians, among such other contemporary shamans as psychologists, anthropologists and physicists.

The author of "Communication Measures to Bridge Ten Millennia" is of course a semiotician, Thomas A. Sebeok of the University of Indiana, one of semiotics' major temples, and he recommends that information about the lethal nature of the nuclear waste dumps "be launched and artificially passed on into the short-term and long-term future with the supplementary aid of folkloristic devices, in particular a combination of an artificially created and nurtured ritual-and-legend. . . . A ritual annually renewed can be foreseen, with the legend retold year-by-year. The actual 'truth' would be entrusted exclusively to -- what we might call for dramatic emphasis -- an 'atomic priesthood,' that is, a commission . . . . (that) would be charged with the added responsibility of seeing to it that our (warning), as embodied in the cumulative series of metamessages, is to be heeded -- if not for legal reasons, then . . . with perhaps the veiled threat that to ignore the mandate would be tantamount to inviting some sort of supernatural retribution."

The burial grounds, which must necessarily be considered sacred, would be bordered by stone monoliths -- rather like Stonehenge with warning symbols, a skull and crossbones, perhaps, assuming that the people of the 120th century still recognize skulls and other images of doom (and have Geiger counters as well). I think various passages from the new scriptures -- "And it is written that thou shalt not trespass on the glowing sand," perhaps, "nor eat of the cow on Fridays" -- should be carved into the stones in several languages now extant, on the assumption that one or another of them would be understood. If not, the images would have to do.

As I said, there is something comforting in this Department of Energy report, which is the assumption that earthlings will still be around in 10,000 years. But there is another, more disturbing assumption, too, which is that somehow the normal sequential transmission of information, of the culture -- by word of mouth from generation to generation in the continuously evolving languages of man -- will be interrupted. Such an interruption would be cataclysmic. In that case, these burial vaults for our radioactive wastes would probably be the safest site around. But in times of greatest danger, men have traditionally taken refuge in temples. Nothing new about that.