Having felt the sting of its radiation as far away as France and Sweden, the West was more than happy to pick up the tab for taking Chernobyl offline in December. But the Ukrainian plant's sole surviving reactor is only one of many Soviet-era, RMBK-type reactors still operating throughout Central and Eastern Europe — and that's a problem that'll likely loom for decades. President Leonid Kuchma announced the plant's final closure Monday to coincide with President Clinton's visit to the Ukraine. Washington will provide some $78 million in aid to secure the reactor that blew up in 1986, killing some 31 people immediately and some 15,000 relief workers in the months that followed, as well as exposing some 5 million people to radiation.

Radioactivity generated by the explosion will remain dangerous for thousands of years, while the concrete sarcophagus in which the damaged reactor is entombed is reportedly crumbling, and requires extensive work to avoid further radiation nightmares. But while it might have burned its fingers (and a lot more) at Chernobyl, the Ukraine government hasn't exactly sworn off nuclear energy. It had kept one of Chernobyl's four reactors operational until now, saying Western donors had failed to come through with aid promised to build two replacement reactors at Rivne and Khmelnitsky.

"The new reactors are certainly preferable to the old Soviet-model graphite gas ones, which were dangerously volatile," says TIME correspondent William Dowell. "At least the pressure-water reactors used in the West slow down the nuclear reaction in event of problems, as opposed to speeding it up as happened at Chernobyl. But in the long view, Chernobyl may serve as a reminder that both East and West adopted an extremely dangerous energy technology without fully understanding its costs and consequences — nobody really considered what would happen to spent fuel, for example."