`CHAIN REACTION' TAKES US ON SPEEDING PURSUIT OF FUN.

Byline: Amy Dawes Daily News Staff Writer

In one of the many great action scenes in the high-tech thriller ``Chain Reaction,'' Keanu Reeves, as a fugitive on the run, escapes the cops by running up the Michigan Avenue drawbridge in Chicago while it's in motion. As he clings to the top, he's got police boats circling below him and helicopters buzzing him from above. Then the bridge operator decides to shake him loose by lowering the massive bridge.

Knocked down to a lower level, Reeves manages to scramble away from his pursuers. He dashes to a train platform where his damsel in distress, a physicist named Lily (Rachel Weisz) is awaiting him so they can make their getaway. ``You're late,'' he's told. ``The bridge was up,'' he quips, and the action rolls on.

Director Andrew Davis, whose biggest hit was ``The Fugitive,'' has returned to what he does best, delivering a taut, intelligent thriller, beautifully filmed and edited, with inventive, nonstop action and two of the most spectacular explosions yet seen in the movies.

Reeves plays Eddie Kasalivich, a young machinist in the science lab at the University of Chicago who's part of a team that's on the verge of unveiling a breakthrough discovery that could provide the world with cheap, nonpolluting hydrogen energy.

The team has learned how to extract hydrogen from water using a process called sonoluminescence, which traps intense sound waves in liquid and produces bubbles of gas containing so much energy they light up a room.

But as they prepare to announce it, thugs descend on the lab, murder the chief scientist (Nicholas Rudall) and set off a hydrogen explosion so enormous that it billows up like an atomic bomb and levels eight blocks. Fleeing from that explosion on a motorcycle by the skin of his teeth is Eddie, who soon finds that incriminating evidence has been planted in his apartment and he's been framed.

Also under suspicion are research team members Lily and Dr. Lu Chen (Tzi Ma), an Asian scientist who has suddenly disappeared.

As the authorities close in on them, Eddie and Lily go on the run in a determined struggle to elude capture till they can prove their innocence.

Sorting things out with the boys from the FBI is Eddie's friend and mentor, Paul Shannon (Morgan Freeman), a complex, shadowy bureaucrat who fronts the foundation that funded the energy project. Whether Shannon is really friend or foe is part of the mystery that hounds the fugitives in their battle for survival.

If the movie is starting to sound a lot like Davis' ``The Fugitive,'' in which Harrison Ford went on the lam after being wrongly convicted of murdering his wife, it is.

Strip away the alternative energy plot and you've a ripping good chase yarn, in which the wrongly accused fugitives (this time there are two of them) race through city streets and corridors, through winter woods and across frozen lakes to tirelessly elude capture.

Chase scenes are what Davis does exceedingly well. One scene takes place on a frozen lake, where Reeves commandeers an Everglades-style air boat meant for rescue operations and uses it to skim himself and Lily away from the baddies at 90 mph. Not only have we never seen it before, but it looks like a lot of fun.

Suspense is used skillfully at every turn. And the movie's bookend explosions - one starts the action, another finishes it - let loose enormous clouds of fire that billow and build on themselves and detonate everything in their paths, to spectacular effect.

Best of all, this is a movie that gets along just fine without gratuitous violence or vulgarity. The body count is low; the gore is absent except for some brutal hand-to-hand combat in a fight scene.

As an action hero (he first tried this in ``Speed''), Reeves brings an unusual gentleness to the genre, offsetting his youthful, sensual features and feline grace with a gritty, dependable attitude that works just fine for some of us.

Filmed in Chicago in the dead of winter, the movie gets an extra visual edge from its stark surroundings. Somber blues and grays are framed against stark white woods; when Eddie and Lily run through a snow-pelted forest, their scarves flapping behind them, the effect is mesmerizing.

Behind all the action is the idea that solutions to the world's great problems - like a nonpolluting fuel source, or perhaps equally as threatening, a cure for cancer - inevitably will be defeated by vested interests.

In ``Chain Reaction,'' the villain (who will not be named to preserve suspense) argues that introducing cheap, nonpolluting energy would destroy the world economy. Never mind the consequences of NOT introducing it. It's a compelling conflict, used to frame compelling events. In ``Chain Reaction,'' the collision of interests sets off rollicking action, to the benefit of all.