We're having leftovers today -- not literally a turkey, but perhaps a figurative turkey.

Lloyd Decker of Arlington brings us back from holiday relaxation to a grim world of uncertain oil supplies and equally uncertain substitutes for oil as the major fuel in generating electricity.

In the beginning, Lloyd was an advocate of nuclear power, as were millions of us. "But then came Three Mile Island and a few other accidents that resulted in 'limited' emissions. I considered these caution signals and began to modify my thinking."

The other day I was about to begin another trudge up an inoperative Metro escalator when a manufacturer's logo on that escalator caught my eye.

"I was shocked. A chill clamped my neck and shoulders.

"I had just read the name of a manufacturer who is also a major producer of atomic power plants!

"I love our Metro, but have always considered the escalators a weak link in the system. I rarely use Metro without having to walk up or down at least one escalator. Some are out of service for days on end. One at Gallery Place has been inoperative for weeks.

"My thinking on nuclear power plants has now changed. I believe we should go slow, use fail-safe procedures, and convert those plants in populations centers to coal.

"Have I gone a little bit bonkers on the subject?"

No, I don't think you're any more bonkers than the rest of us are, Lloyd. I have gone through a similar shift in opinion, and I get the impression that many Americans have. We're all having some second thoughts, and even those who still favor nuclear power plants are conceding that safety factors need review and correction.

I think that only your penultimate paragraph will generate major disagreement. What does "go slow" mean: Stop building new ones? Don't finish plants that are almost ready for operation? Don't license new construction plans? Shut down existing plants until we make a thorough study of possible construction flaws and operating procedures?

The conversion to coal sounds good until we realize the environmental implications. Then, too, there is a practical consideration: It would take quite a while to convert to coal and to begin mining enough coal to meet the new needs. Public utility companies would have to raise construction capital at a time when the prime interest rate is at an all-time high, and the consumer would, as always, have to pay the cost.

Nuclear power may, in the long run, turn out to be a turkey -- a blind alley that we never should have turned into. On the other hand, we may be able to find a way to use it safely. Right now, we need it, and all our options are onerous. When a keyboard error makes "nuclear" come out "unclear," I sometimes wonder whether there is a Freudian connotation in the mistake. NOBODY IS PERFECT

Government Executive Magazine reported recently on some crash tests conducted by the National Highway Transportation Safety Administration.

Various autos were driven into a brick wall to find out what would happen to the cars and to any occupants that might have been in them. At 35 miles an hour, several models passed the test, but when the speed of impact was raised to 48 miles an hour, only NHTSA's $250,000 safety research vehicle passed.

After the tests, a local contractor was hired to mash the wrecked cars flat, then bury them. And he did.

The research vehicle was, inadvertently, also left on the site. "It was routinely picked up along with the wrecks. It was impacted. It is now about eight feet under . . . . The brick wall, however, is still there."

Bob Boaz, head of public affairs for NHTSA, concedes that "a mistake was made," but says the loss was not catastrophic. NHTSA built a dozen of its safety research vehicles and expects that eventually the other 11 will also be demolished in tests. ADD SIGNS

Hap Traub of Martinsburg, W. Va. reports that he saw this sign in a filling station: "Positively no smoking near the gas pumps. Your life may not be worth anything, but gasoline damn sure is." CRIME NEWS

Time and Tide, the inmate publication at the Lorton correctional complex, complains that very few people who drive on the roads adjacent to the institution pay any attention to stop signs. AIN'T IT THE TRUTH?

Changing Times says, "If something isn't done to make people find their credit cards before they get to the cashier, the American way of life may be bottlenecked out of existence."