Twenty-five years after the tragedy at the Chernobyl power plant in Ukraine, tons of concrete shield workers and visitors from the puddle of dangerously radioactive melted fuel that lurks in the basement. In contrast, more than 30 years after the accident at Three Mile Island near Harrisburg, Pa., the next-door twin of the partially melted-down reactor is still in operation and surrounded by homes. Eventually the plant will be torn down and the site cleaned up.

These two scenarios—continued operation followed by cleanup versus abandoning and entombing the site—bookend the possible outcomes for the newest member of the nuclear meltdown club, Fukushima Daiichi. The Japanese plant has endured partial meltdowns in at least three of its six reactors, as well as two of its seven pools for storing spent fuel. “You have several [impacted] reactors, and you could easily have two or three approaches to decommissioning,” says Kurt Kehler, vice president of decommissioning and demolition at CH2M HILL in Englewood, Colo.

Fukushima’s fate will ultimately come down to how badly the fuel at the plant melted, how deeply contaminated the site has become and how much money the Japanese government is willing to spend on cleanup. Tokyo Electric Power, which operates the plant, estimates that the fuel in at least one of the reactors has completely melted down. If so, the fuel rods may have formed a “puddle,” not unlike the one at Chernobyl that has necessitated a massive steel structure to contain it. Moreover, radioactive contami­nation has spread to a 30-kilometer radius of the stricken plant, including to towns even farther afield, such as Iitate, which is so contaminated that it will have to be abandoned or its soil scooped up and entirely replaced. Some 80,000 residents in similar towns have been evacuated.

The Japanese government has called for the plant to be torn down. TEPCO would prefer to restart the undamaged reactors if at all possible. Unfortunately, neither may get its wish: if the fuel has indeed formed a puddle, radiation levels may be too high for would-be deconstruction workers to approach, necessitating entombment efforts similar to those at Chernobyl. And like the Ukrainians and Belarusians who never returned to the exclusion zone, residents in the towns near Fukushima Daiichi may never return home permanently, and local farmers and fisherfolk may not be able to resume their professions. In short, the area surrounding Fukushima may remain a no-go zone for years to come—another name on the list of unexpected nuclear parks and another reminder of the peril of nuclear ­energy.