Airborne Plutonium and Non-Natural Uranium from the Fukushima Daiichi Nuclear Power Plant Found at 120 km Distance a Few Days after Reactor Hydrogen Explosions
A large scale earthquake (moment magnitude 9.0) occurred on March 11, 2011 in the northwest Pacific generating the tsunami which seriously damaged the Fukushima DNPP. Following the incident, numerous amounts of fission products such as radio Cs and I were released from the reactors. Actinides, such as plutonium and uranium which are the main component of nuclear fuel materials were also released into the atmosphere. However, regardless the hazard of the actinides, it is very difficult to analyse them in the environmental samples precisely due to the low abundance and difficulty of analysis. In this study, we analysed airborne plutonium and uranium in aerosol samples collected at 120 km distance of Fukushima DNPP before and after the accident. The results of isotope ratio of plutonium and non-natural uranium show that the Fukushima origin actinides arrived at 120 km distance after 2 days of the reactor explosions. The effective dose of plutonium was calculated using the obtained results. The results show that the dose effect is smaller than that of radio Cs and I, but indicate possible hazards by plutonium against human health. The work could only be carried out through high quality analytical techniques. The results are the first findings and the first publication relating to the Fukushima origin airborne plutonium and non-natural uranium at such a distance of the atmosphere from the FDNPP.
Shinonaga T, Steiner P, Lagos M, Ohkura T. (2014): Airborne Plutonium and Non-Natural Uranium from the Fukushima DNPP Found at 120 km Distance a Few Days after Reactor Hydrogen Explosions. Environmental Science & Technology 2014; 48: 3808-3814.
Bedeutung für die Mission des Helmholtz Zentrums München:
The Helmholtz Zentrum München studies radionuclides in the environment and radiation protection issues to prevent adverse health effects. The behaviour of actinides after the Fukushima DNPP has been studied in the fields near to the reactors. We calculated effective dose of plutonium using the obtained analytical results. The results of the study provides important information on the behaviour of actinides released from a nuclear power plant accident, which can be used for evaluation of risk to human health.