81.   Putin also sacked Atomic Energy Minister Yevgeny Adamov, who had advocated a much-criticized plan to import foreign spent nuclear fuel into Russia for long-term storage.

82.   Rupture also could spill spent fuel pellets into the reactor core, forcing a costly and time-consuming cleanup that would delay restarting the reactor.

83.   Russian officials balked at accepting the spent fuel, saying they had their own environmental laws to worry about.

84.   Several have now been retired, still storing spent fuel.

85.   So the spent fuel risk, however great it turns out to be, will stay with the plants for years to come.

86.   So a major policy issue that remains is how to store the fuel, which is now kept mostly in spent fuel pools around the country.

87.   So scores of nuclear plants around the country will soon find that they, too, have run out of room to store spent fuel.

88.   Some land-starved countries are already having trouble disposing of spent fuel -- South Korea expects to fill all its storage sites in a decade.

89.   Some experts have said terrorists might try to make a radiological bomb by combining radioactive material, like spent nuclear fuel, with conventional explosives.

90.   Since the fuel is moved from the reactor after about three years, it begins to accumulate in the spent fuel pool.