>The controversy has reached Japan's embattled Prime Minister Naoto Kan. Shortly after 7 a.m. that same morning, Mr. Kan paid a 50-minute visit to the Fukushima Daiichi grounds and held a meeting there with plant executives. Opposition lawmakers have argued that his visit distracted plant managers, while Mr. Kan's supporters say he pushed to accelerate venting.
>Another key difference: U.S. rules put the person at the controls of the plant in charge of venting. In Japan, it is common for operators to bump the decision to company or government superiors when there is a chance radiation will be released.