THE CHINA SYNDROME -- Aspen Hill, Jenifer, K-B Langley, Marlow, New Carrollton and Tyson's Twin.

The title is in officialese, the star is Jane Fonda and the scene is a nuclear power plant, so it is probably necessary to state that there is nothing dreary or preachy about "The China Syndrome." That is a weak and negative way of saying that this is a terrific film, the triumphant culmination of many elements that have been attempted in previous ambitious films.

This has a wealth of true movie ingredients: two or three meaty subjects handled with naturalistic ambiguity, suspense, a variety of interestingly developing characters finely acted, excitement and authenticity laced with restrained satire.

Fonda's devastating portrait of the female member of a television news team, who gets to cover the tiger's birthday party at the zoo and to be told how brilliantly she does this instead of being promoted, is alone worth the price of admission.

But so is Jack Lemmon's incredible scene as a scientist so unable to translate the warning of instant annihilation into quickie simplicity for TV that he produces a television image of craziness.

The China Syndrome refers to the possibility of a nuclear plant's "going to China" the way an American child sets out to when he digs a hole in the ground.

Fonda has been doing a cute feature on the plant, shushing a cameraman from making bomb cracks by insisting that she wants "coverage, not controversy." Only they happen to witness a major accident, and, while they don't understand it, and Fonda is only too ready to be satisfied with a variety of smooth explanations, there is obviously news there that refuses to go away.

The issue of the film is not whether the plant should exist. Those who picket it are handled with even colder deftness than the characterizations of the workers who love the plant and believe in it. When you watch the protesters indulging in such gimmicks as reading solemnly and publicly the names of their as-yet-unharmed children, it is clear that their side gets no favoritism from the filmmakers, who include Fonda's producer partner Bruce Gilbert and James Bridges, who directed and was one of the writers.

The issue is really job loyalty: How much should be to the profession, rather than the job, how much to the pragmatic welfare of the employer, how much to one's own career, how much to one's colleagues, how much to the public? A neat counterpoint shows this through Fonda's career in television news, and Lemmon's in the power plant. Because the catalyst is a freelance cameraman, the possibility is there that these are ultimately irreconcilable in a normal working situation. That part is well played by the film's producer, Michael Douglas, but it's a simple role compared to Lemmon's and Fonda's, because a self-employed person has the luxury of uncomplicated idealism, while the others must sacrifice for it.

The authenticity of the professions portrayed in the film is amazing. Science naturally lends itself to being shown with more dignity than newscasting. But the general view of the latter is so devastating, with its phony on-the-air kidding and its cheerful balance of the news from the Middle East with a feature on a fish veterinarian who makes house calls, that it's surprise to find that stations are still scheduling their news shows tonight.

Just a few of the fine moments are:

Wilford Brimley, as a man whose professional competence makes him impatient with the moral questions, when he suspects that he, as the only non-Navy official, will be the scapegoat. Why? "Tradition."

James Hampton, as the plant's public relations man, showing his sub-specialty professionalism by speaking calmly, while he knows the plant may blow any second, those immortal words: "We don't have anything to say now. If you gentlemen would just be patient."

Fonda's pausing, before she puts Lemmon on the air to announce the possible blowup, to smooth his eyebrows for the camera.

Lemmon's watching television, in a state of anxiety from having agreed to cooperate with Fonda, and seeing her, in whom he has placed his future, doing one of her mindless feature spots.

But it is futile to try to list the moments in this film in which drama has been perfectly used to say something important. That would come close to the running time of the picture.