"Indian Point: Imagining the Un- imaginable" (8 p.m.), about a nearby power plant, will make you think.

"Chernobyl Heart" (8:45 p.m.) deals with a plant a world away. It will break your heart.

On the eastern shores of the Hudson River, a little more than 110 miles south of Albany and just 35 miles north of Manhattan, sits the Indian Point Energy Center and its two nuclear reactors. In "Imagining the Unimaginable," filmmaker Rory Kennedy (daughter of Robert F. Kennedy) examines how vulnerable the aging plant is to terrorist attacks.

(Before you get excited: Terrorist groups already know about Indian Point. President Bush said as much in his 2002 State of the Union.)

The filmmaker's brother -- Robert F. Kennedy Jr., an attorney for the environmental conservation group Riverkeeper -- is the most prominent screen presence in the documentary. He calls the plant "arguably the most attractive terrorist target in the world." He lives 12 miles away.

The film states that in the event of a catastrophic accident or attack, a 50-mile radius around Indian Point, an area of 20 million residents, would be uninhabitable. In short, New York City would cease to exist.

Rory Kennedy, who also narrates the movie, does a good job highlighting the dangers of the plant, both in security and operation, and how evacuation plans in the event of an incident are inadequate.

But the documentary ultimately fails. Missing is a critical element: What should be done? Where do we go from here? The dangers of terrorism are well established; how we should address the security issue surrounding plants is not. This is where the documentary fails to live up to its promise.

Immediately following "Indian Point" is the Oscar-winning documentary "Chernobyl Heart." The title refers to a common heart ailment in the region around the Chernobyl nuclear power plant in Ukraine.

In aching, ghastly detail, the film, by Maryann De Leo, follows Adi Roche, founder of Ireland's Chernobyl Children's Project. Roche traveled through the region 16 years after the April 26, 1986, nuclear power plant accident that killed thousands and affected millions -- a mishap that continues to sicken and kill thousands today. The 30-kilometer area immediately around the plant, called the exclusion zone, remains the most radioactive place on Earth.

People still live there.

In fact, 99 percent of the nation of Belarus, part of the former Soviet Union, is contaminated with radioactive material. (Some radiation reached as far away as Scandinavia.) Fewer than one in five children living there are born healthy. Late teens and early 20- somethings are at great risk for thyroid cancer, newborns to a host of ailments.

The camera follows Roche to Minsk and elsewhere. Most haunting are the asylums and orphanages, where babies and young children endure ghastly birth defects linked to the nuclear accident. Some of these defects defy description, appearing to be concocted by some Hollywood special-effects artist. They are real.

The documentary notes that less than 3 percent of Chernobyl's potential radiation has yet to be released from a plant that is hardly shored up.

"The next Chernobyl," Roche says in the film, "will be Chernobyl itself. ... I'm terrified."

We all should be.

Mark McGuire is the Times Union TV/radio writer. Call him at 454- 5467 or send e-mail to mmcguire@timesunion.com.