While some say Japan is overreacting (http://www.guardian.co.uk/world/2011/apr/12/japan-nuclear-crisis-chernobyl-severity-level1). I’d have to favor the guy that’s managing the facility itself – and what he says ‘aint pretty:

“The radiation leaks haven’t stopped,” Junichi Matsumoto, general manager of the utility’s nuclear power and plant fitting division, said in Tokyo today. “If the leaks continue, the total radiation from the reactors may exceed” that from Chernobyl.

via Japan Lifts Atomic Alert to Highest Level, Matching Chernobyl – Bloomberg.