Radiating Mystery : Meryl Streep stars as a nuclear whistle-blower in the true story of ‘Silkwood.’

Was she murdered to be kept silent, or was she doped up and crashed the car herself?

That’s the unanswered question at the climax of “Silkwood,” the 1983 Meryl Streep-Cher film based on the true story of Karen Silkwood, the bad-girl union activist who blew the whistle on the Oklahoma plutonium plant where she worked.

One indelible scene endures: Streep, as lab analyst Silkwood, after being exposed to high levels of radiation, rubbing her skin red in a terrorized, irrational attempt to scrape the stuff off.

In real life, the contamination occurred at the Kerr-McGee plutonium facility, where, in 1974, Silkwood died in an auto crash at 28. She was heading to an interview with a New York Times reporter, purportedly bringing documents (never found) that she believed proved a cover-up of serious radiation safety violations at the plant.

Some of Silkwood’s colleagues, beside whom she handled dangerous, highly radioactive plutonium, contended she was murdered by her employers, fearful of being exposed.

Others, afraid they’d lose their jobs over her related union activism, were sure that the crash was her fault, caused by her known use of tranquilizers and pain pills. Some employees, according to the New York Times, even thought she caused her own contamination in a wrongheaded effort to illustrate the lax safety conditions at the plant, which was later shut down.

If the answers to these conundrums are known, however, the movie doesn’t deliver them, which prompted critics to call its ending a confusing muddle of fact and fiction.

Still, until the film’s final scenes, it’s “a very moving work about the raising of the consciousness of one woman of independence, guts and sensitivity,” wrote Vincent Canby of the New York Times.

Its cast won praise, as well. Streep, wrote Canby, delivers a “brassy, profane, gum-chewing tour de force, as funny as it is moving.” Cher, who played Streep’s lesbian housemate, garnered an Oscar nomination.

Kurt Russell, as Streep’s boyfriend, fed up with her activism, also was lauded for his star-quality good looks and characterization, as were director Mike Nichols and screenwriter Nora Ephron, in part for their trenchant depiction of a small-town middle America with such characters as Angela, one of Cher’s lovers, who works as a beautician in a funeral parlor.

What ultimately happened to Silkwood’s bereaved family? Their attorney, Gerry Spence, won an initial $10.5-million civil damage award from Kerr-McGee. It was later reduced to $1.38 million, but the case brought national fame to Spence, whose closing statements contained one of the better known legal lines of all time.

“If the lion gets away, Kerr-McGee has to pay,” said Spence, contending that the plant was just as responsible as a circus ringmaster whose lion escapes to harm people.

* “Silkwood” screens today at 7:30 p.m. at the Unitarian Society of Orange County, 511 S. Harbor Blvd., Anaheim. Free. Running time: 128 minutes. Rated: R. (714) 525-1348.

Masters at Work in ‘Autumn Sonata’

A truly magnificent trio--Ingrid Bergman, Ingmar Bergman and Liv Ullmann--makes “Autumn Sonata” (1978) worth seeing, even if it’s reminiscent of the director Bergman’s earlier films.

The actress Bergman, appearing in her final film, plays a glamorous concert pianist opposite Ullmann, her resentful daughter, in this intense portrait of a troubled home life.

* “Autumn Sonata” screens Friday at UCI Student Center, Crystal Cove Auditorium, West Peltason and Pereira drives. 7 and 9 p.m. Running time: 97 minutes. $2.50-$4.50. (949) 824-2727.