Environmental Safety

　We can live with peace of mind only if we have a safe living environment. With the development of science and technology, we are living a convenient and comfortable life, but in reality we may be at risk. The nuclear power plant, which was considered safe, caused a serious accident due to the tsunami after the earthquake in Japan. The staff of our laboratory also visited Fukushima several times to support the screening work when the residents of the evacuation area returned home temporarily. When we measured the dose by a radiation detector we brought from Kyushu University, a relatively high dose was detected on one side of the trees in the park (probably on the windward side), the side groove accumulating leaves , and the tires of police cars.Currently, many researchers are studying how radioactive substances such as cesium released from F1 power generation station are transferred in the environment.
　In our laboratory, we are engaged in research related to environmental safety by utilizing our know-how in mass transfer engineering, separation engineering, and radiation engineering.

Related research in our Lab.

• Study on mass transfer behaviro of tritiated water in natural soil

Tritium is a radioactive isotope of hydrogen that emits low-energy beta rays. The half-life is 12.3 years. トIt is known that tritium is generated in a nuclear reactor by the three-body fission of uranium and the nuclear reaction of boron and lithium, and a part of it exists in the cooling water. In this research, we aim to develop a technology to predict in advance how water containing tritium will diffuse and migrate to the surrounding environment assuming a severe accient of tritiated water flowing out to the soil.Furthermore, based on the understanding of tritium fundamental transport phenomena obtained in this study, we are also considering the development of methods to suppress the diffusion of tritium in soil. So far, we have conducted permeability experiments of tritiated water through the soil packing bed, and are proceeding with the accumulation of useful data.

• Study on tritium transfer from soil to plants

　Tritiated water that has permeated the soil stays for a certain period of time, and part of it evaporates into the atmosphere.During this time, plants living in soil containing tritiated water take up tritium into the body as well as absorb water from the roots. Most of the tritium stays as tissue free water and is released to air through transpiration and isotope exchange reaction with water vaporHowever, some tritium becomes organically bound tritium through photosynthesis and accumulates in plants. In this study, in order to clarify the relationship between the amount of organic-bonded tritium in plants and the growth environment, we are growing plants in a controlled tritium environment and trying to evaluate the amount of tritium accumulated in the plants.

• Study on mass transfer of carbon fine particles

　In recent years, research and development of nanomaterials has been progressing rapidly, but on the other hand, there are concerns about its toxicity. In addition, as has been widely known for a while, the national government has taken measures against the particulate matter PM contained in the exhaust gas from power generation facilities and the exhaust gas of automobiles. In this research, we will first proceed with basic research from the viewpoint of mass transfer engineering on how carbon fine particles behave.

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