It turns out groundwater near the Fukushima Daiichi nuclear plant is dangerously high, after all. After Tokyo Electric Power Company found levels of radioactive iodine 10,000 times the legal limit, Japan's nuclear safety agency ordered the utility to check its data, thinking the reading was suspiciously high. It wasn't an error: Tepco confirmed that levels of radioactive iodine were indeed that high. Radiation in seawater outside the plant also increased to 4,385 times the permissible level, up a third from the day before. The surge in radiation prevented workers from getting near the plant, once again halting efforts to pump radioactive water from the tunnels beneath the station and restore power to the cooling pumps. Engineers speculate that the radiation surges may be the result of "localized criticality," the emission of short flashes of radiation as small segments of the fuel rods melt.