International collaborative research project for the development of low carbon nuclear energy systems
The emission of carbon dioxide arising from the use of fossil fuels is having an increasingly critical impact on the global environment. Reducing fossil fuel consumption and carbon dioxide emissions is an urgent task to ensure the sustainability of the economy as well as the environment. Renewable energies are one alternative solution to this problem, but are characterized by problems with output instability and low operation ratio. Nuclear power generation is another alternative primary energy source that can supply baseload energy stably and at low cost. However, the core melt-down at the TEPCO Fukushima Daiichi Nuclear Power Plant that occurred in the wake of the Great East Japan Earthquake of 2011 caused environmental pollution through the release of radioactive materials. As a consequence, public acceptance of nuclear energy as a viable alternative to the urgent problem of carbon pollution has declined.
This project aims to develop next generation nuclear energy systems that address the above technical problems associated with nuclear power. Specifically, we are currently involved in the development of thermochemical energy storage for high efficiency utilization of nuclear heat (Kato, Aristov, Takasu) and advanced metal materials to greatly strengthen nuclear reactors against severe accidents (Kobayashi, Ballinger).
- Developing technologies to more effectively utilize nuclear heat
In Japan, 25% of all energy consumption is in the form of electricity, while the remaining 75% is consumed as thermal energy. The effective utilization of thermal energy is therefore essential to realize a low carbon society. This project aims to develop a nuclear heat storage system and heat utilization technology. Thermochemical energy storage (TCES) has the advantage of high density and long-term heat storage that is widely applicable to a variety of heat sources and temperatures. Initially, we are focusing on TCES system development for nuclear heat utilization, and we will also be developing a novel porous composite TCES material that can operate under various temperatures and operating conditions while retaining high reactivity. This research promises applications not only in nuclear power, but also to output leveling of renewable energy systems and efficient usage of surplus heat in industry.
- Devising new metals for nuclear reactor safety and protection against severe accidents
This aim of this part of our research is to ensure the safety of nuclear reactors for the entirety of their service lifetime, as well as protection against possible severe accidents by developing metallic materials that are extremely reliable and robust. In addition, in order to assess the damage within the Fukushima Dai-ichi nuclear power plant following the nuclear accident, we need a better understanding of the damage and collapse behavior of structural metals within the reactor core. This research is also important as we develop methods to most safely dispose of nuclear material arising from the Fukushima Dai-ichi nuclear power accident. To these ends, we are studying the control and reduction of impurities in materials, as well as the reactions between fuel debris and stainless steel as reactor core materials.