Radiation Readings in Fukushima Reactor Rise to Highest Since Crisis Began --Tepco plan to flood containment vessel of reactor No. 1 with more water to speed emergency cooling efforts announced yesterday 'may not be possible now' 27 Apr 2011 Radiation readings at Japan’s Fukushima Dai-Ichi station rose to the highest since an earthquake and tsunami knocked out cooling systems, impeding efforts to contain the worst nuclear crisis since Chernobyl. Two robots sent into the reactor No. 1 building at the plant yesterday took readings as high as 1,120 millisierverts of radiation per hour, Junichi Matsumoto, a general manager at Tokyo Electric Power Co., said today.