By Masamichi Kagaya (Photographer) and Dr. Satoshi Mori (University of Tokyo)
As a consequence of the Great East Japan Earthquake and ensuing tsunami on March 11, 2011, the cores of the first to third nuclear reactors at the Fukushima Daiichi Nuclear Plant underwent meltdowns as external power for the cooling pumps was lost. As a result, a huge amount of radioactive particles was released into the air. These particles were carried by southeasterly winds to Iitate Village, Fukushima City, and Nakadori, a central region of Fukushima Prefecture, leaving high levels of radioactive contamination in their wake. The particles were further carried along multiple routes creating radioactively contaminated areas in regions from Ibaraki to Tokyo and Kanagawa Prefecture, as well as in Northern Kanto and the Tohoku Region (Northeastern Japan).
Whether we are in Tokyo, Fukushima, or even in front of the damaged nuclear reactor buildings, we are exposed to radiation that we are unaware of. It is too small to see, it cannot be heard and it is odorless. Therefore, despite living in a region contaminated with radioactive particles, to this day, we are not consciously aware of the radiation. NaI (TI) scintillation detectors and germanium semiconductor detectors are used to measure the amount of radioactive contamination in soil, food, and water in units called Becquerels (Bq). Radioactivity is further measured in Sieverts (Sv), which is an index of the effects of radioactive levels in the air, doses of exposure, and so on. Nevertheless, from such values, it is impossible to know how the radioactive particles are distributed or where they are concentrating in our cities, lakes, forests, and in living creatures. These values do not enable us to “see” the radioactivity. Thus, radioactive contamination has to be perceived visibly, something that can be done with the cooperation of Satoshi Mori, Professor emeritus at Tokyo University. Professor Mori is using autoradiography to make radioactive contamination visible.
Today, dozens of radiographic images of plants created by Professor emeritus Mori since 2011 are on display together with radiographic images of everyday items and animals. This collection of radiographic images (autoradiographs) is the first in history to be created for objects exposed to radiation resulting from a nuclear accident. I hope that visitors will come away with a sense of the extent of contamination in all regions subject to the fallout — not just those in and around Fukushima. At the same time, I hope that this exhibition will remind visitors of the large region extending from the Fukushima Daiichi Nuclear Power Plant to Namie Town, Iitate Village and the dense forests of the Abukuma Mountain Area that, to this day, remain restricted areas. The radiation affects animals that continue to live in these areas and be exposed to heavy radiation, as well as the 140,000 people that had to evacuate and who lost personal assets (homes, property, work, interpersonal relationships). These people are in addition to the victims who directly breathed in the radioactive materials, subjecting them to internal exposure — victims that include anyone from the residents near the plant to people in Tokyo and the Kanto Region.
Although what can be done is limited, new progress has made it possible to record the otherwise invisible radioactivity and make it visible. The history of needless nuclear accidents occurring in the United States, the Soviet Union (Russia) and Japan over the last several decades may still potentially be repeated elsewhere in the world, but hopefully future generations will see the cycle be broken. Through exhibitions and other means of disseminating knowledge about radioactivity, future generations may learn to leave behind dependence on nuclear power and be free from the dangers of nuclear accidents and nuclear waste.