I don't know if nuclear power is destined to prove the ultimate boon or bane of an energy-hungry civilization. Jane Fonda, Michael Douglas, Jack Lemmon and the other deep thinkers responsible for "The China Syndrome," opening today at area theaters, obviously prefer the bane theory. However, it becomes apparent during the stuttering course of the movie itself that exploiting a nuclear power plant as an effective deathtrap in a doomsday thriller requires more than melodramatic wishful thinking.

"The China Syndrome" belongs in the same ponderously alarmist class as "Twilight's Last Gleaming," from which it borrows the clever device of wrapping up a stale exposition with a messy climax. Despite the pretense of a suspense melodrama framework, "The China Syndrome" is fundamentally a platform for arguments against nuclear power, an ongoing bete noire in politically active private life to both Fonda and Lemmon.

Lemmon contributes a persuasively alarmed, resolute performance as the only major character who seems to have a purposeful role to play in the given circumstances -- Jack Godell, a shift supervisor who is on duty when something malfunctions at a nuclear plant in southern California and fears that this near-accident might foreshadow something drastically amiss. Godell's anxious moments in the control room are inadvertently witnessed by the Fonda character, Kimberly Wells, a TV newscaster specializing in "soft" features, and surreptitiously photographed by the Douglas character, Richard Adams, a bearded, radical hothead of a cameraman.

Wells, who longs to move up from soft stuff to the heroic dignity of "hard" news and probing investigative journalism, gets all excited about her perplexing scoop and wants to break it immediately. She is prevented by the smooth station manager, played by Peter Donat, who justifiably points out that they don't know what was going on in the control room and that they violated federal statutes by photographing the technicians' frantic pantomime on the sly.

At this primitive stage of her development Wells submits meekly to the boss' authoritative masculine reasoning. The hothead, instinctively recognizing the start of yet another corporate cover-up, absconds with the incriminating footage in order to have it interpreted by renegade nuclear engineers participating in organized protests against the construction of a new plant.

Back at the existing plant, the conscientious Godell worries that an accident hearing by the Nuclear Regulatory Commission may have been too swift to get to the bottom of things. (Unbeknownst to Godell, the board chairman of the utility company has ordered his operations chief to softsoap the NRC, since public hearings on the licensing of that new plant are in progress.) Searching the premises, he finds a leak on the floor near the reactor. Searching the files, he comes upon some suspect welding X-rays of the pump support system. When he confronts the contractor with this irregularity, Godell is threatened with foul play.

After screening the purloined film, the experts sagely inform Wells and Adams that Godell and his staff probably had a brush with "the China syndrome," a worst-case disaster prospect in which the loss of coolant around the reactor would "expose the core," which might then burn through the foundation of the plant and come out in China. That's the theory. It's more likely that the core would hit underground fissures or water sources and merely bring nuclear disaster to southern California.

Godell dismisses this interpretation when Wells and Adams confront him with it. Nevertheless, he is concerned about those faulty welds and agrees to pass them the incriminating X-rays for presentation at the hearings. The courier, Adams' likable Chicano soundman, is forced off the road by a murderous Ford van in a scene that recalls both "Duel" and Jane Fonda's thwarted desire to portray Karen Silkwood.

Godell eludes another set of assassins and arrives at the plant to discover that the company is going to full power, a step he considers sheer folly. Perhaps recalling the crazed general played by Burt Lancaster in "Gleaming," Godell takes the law into his own hands. He seizes a revolver from the inattentive guard, clears the control room and demands that Wells and Adams be summoned so that he can make a full statement on television.

The exposition gets hilariously helter-skelter at this point. While Wells and Adams set up their remote exclusive, all the other stations converge on the plant. At the same time the fantastically ruthless and oblivious board chairman, restored as the ultimate villain of the fable, has called out for a SWAT team to snuff Godell and ordered other technicians to rewire the joint and restore that power no matter what.

During scenes set at public hearings on the licensing of the proposed nuclear plant we're shown protesters engaged in such amateurish theatrical gestures as raising photos of children and binding their mouths for five minutes of silent disapproval. Nevertheless it's impossible to believe that the people in charge of this particular film intended to question the sincerity of such gestures.

These lapses come back to haunt the filmmakers, who prove no more astute at melodramatic theatrics than the demonstrators are at the Theater of Protest. The photogenic weakness of the conception is evident during the first sequences at the plant. Even if something catastrophic is going wrong in such a setting, how do you visualize it effectively? The filmmakers don't have a camera inside the reactor and couldn't solve their problems if they did.

Unlike a rampaging sea monster, a wounded airliner, a burning skyscraper or a crumbling metropolis, a power plant with a faultily welded reactor is not a threat that vividly meets the eye. It's an invisible menace, like the deadly bug in "The Andromeda Strain." This obstacle might be finessed, but James Bridges, the director of "The China Syndrome," does not display miraculous resourcefulness.

On the contrary, he relies on the standard panicky cliches: reaction shots of actors trading grim, tense expressions and a little camera-shaking to threaten structural collapse or maybe chain reactions. The movie's own melodramatic structure is as sturdy as a house of cards. Unable to visualize and concentrate on a monster threat, the filmmakers fall back to the defensive banality of assassins on the road and SWAT teams storming the control room.

Progressive-minded filmmakers no longer depict the nuclear holocausts of their nightmares as they used to in the good old days of "Kiss Me Deadly" and "Dr. Strangelove." Now they prefer to toy with the prospect in a feckless way that makes them look like tiresome polemicists on one hand and timid fantasizers on the other.

The only clever, sophisticated touches in the script are the mocking notes of comedy in the TV newsroom echoing "Network" and "The Mary Tyler Moore Show." Given their knowing disdain for the limitations of personalities like Kimberly Wells, which sounds like the name of a cosmetics and toiletries manufacturer, you'd think the filmmakers would appreciate how dilettantish figures might trivialize a story about a peril at a nuclear facility.

Instead they pretend that a Wells can see that justice is done and earn her stripes as a fearless investigative reporter. In the last analysis "The China Syndrome" lacks the edge of even perfunctory thrillers. It seems like another inspirational promo from Fonda and producer Bruce Gilbert, the same team that raised your consciousness in "Coming Home."