Yoshida sighed as he stood up to leave the meeting He wasn’t worried It certainly didn’t seem likely to him that a 50-foot tsunami would happen anytime soon Fukushima Dai-Ichi 2007
1 AN EARTHQUAKE STRIKES Employees at Fukushima Dai-Ichi oversee the process of loading fuel into nuclear reactor 3
Atsufumi Yoshizawa Fukushima Dai-Ichi March 11 2011 2 46 p m Atsufumi Yoshizawa walked quickly down a long gleaming corridor It was almost the end of his shift Nearly every corner of the sprawling Fukushima Dai-Ichi nuclear plant was clean and orderly just as he liked it Yoshizawa mentally reviewed everything he still needed to finish He had spent the day supervising a routine shutdown of nuclear reactors 5 and 6 and he wanted to be sure everything was in order before he drove home Yoshizawa was an important figure at Fukushima Dai Ichi He was quiet and shy but his 30 years at the plant had given him the confidence and expertise to supervise large crews of workers He knew the inner workings of Fukushima Dai-Ichi by heart He had spent the majority of his adult life monitoring the way the plant utilized a process called nuclear fission to heat giant pools of water When the water got hot enough steam was created and used to turn turbines The plant used these turbines to create electricity The process he knew seemed extraordinarily complex But
to him it was familiar and safe and simple Yoshizawa had often watched the scientists who controlled the plant’s nuclear fission He knew where they stored rods of enriched uranium the plant’s very powerful and dangerous radioactive fuel He loved observing them as they bundled rods of enriched uranium together and then lowered them into water in a pressurized container These bundles would instantly begin to heat the water and create steam In order to keep the bundles from overheating the scientists would use materials called control rods to slow the nuclear fission process If they needed to reduce the temperature of the water they simply lowered the control rods farther into the uranium bundles to slow the rate of the nuclear reactions and therefore reduce the temperature of the bundles When they wanted to increase the temperature of the water they simply removed the control rods from the bundles Everyone at the plant worked hard to make safety a high priority Each of the Fukushima Dai-Ichi employees understood that nuclear fission releases large amounts of radiation that must be contained All employees were well
