Experiences from the Fukushima Disaster

The nuclear accident of the Fukushima Daiichi reactors on March 11, 2011, could have been prevented if the owner and the responsible Japanese ministries had considered the worst-case scenario when planning the reactors near the coast, including at least double redundancy of the emergency system. After the exceptionally strong earthquake, the reactors correctly switched off. The problem started due to the tsunami that destroyed the emergency generators, which should have driven the cooling pumps after the reactor-power had switched off. The Zr-alloy mantles of the fuel rods reacted at the high temperature with water to form ZrO2 and hydrogen. The following explosions, destruction of the reactor buildings and meltdown caused large radioactive clouds and the evacuation of 150,000 people. This chapter shows how by immediate efforts most of this cloud could have been sucked off. The radioactive soil from large contaminated areas was later collected in plastic sacks. Continuous cooling led to huge amounts of contaminated water that was collected in large tanks. In future, the reactor has to be dismantled resulting in contaminated debris. In this chapter, the possible solutions of radioactive cloud, soil, water and rubble problems and the final deposit of used fuel rods are discussed. The experiences could become useful in case of a future nuclear accident.