Japan Institute for National Fundamentals
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Speaking out

【#353】Japan Must Adopt Fast Breeder Reactor

Koji Okamoto ／ 2016.02.02 (Tue)


February 1, 2016

　　　　　As a fast breeder reactor that produces fuel while generating electricity uses dangerous sodium as coolant, experiences and expertise regarding sodium must be accumulated for FBR development. In the meantime, the FBR that uses sodium instead of water for cooling can cool itself through the physical phenomenon of natural convection automatically to maintain its safety even if all electricity sources are lost, as seen in the Fukushima nuclear power plant accident. In a sense, the FBR may be a safer nuclear system than light water reactors at the Fukushima Daiichi nuclear power station. The FBR also has the advantage of producing less high-level radioactive wastes. In 50 years, the FBR is expected to become a mainstream electricity source in the world.
　　　　　Last year, the Nuclear Regulation Authority, which knows nothing about FBR risks and is amateur on nuclear energy, issued a very shameful recommendation. It complained about the reactor by citing maintenance mistakes that have little relationship with FBR safety.

Dust on the back side of a rearview mirror
　　　　　The NRA recommendation amounts to a complaint against dust on the back side of a rearview mirror on a vehicle. The engine and braking system that work well are important for any vehicle. It is important for the rearview mirror to allow the driver to see the rear side. Dust on the back side of the mirror has nothing to do with driving safety.
　　　　　Since any trouble during driving is dangerous, any vehicle is required to undergo safety inspection every two years to secure the working of key equipment. The safety inspection focuses on components that are important for safety and does not cover the back side of the rearview mirror. If the back side of the rearview mirror and the braking system are inspected in the same manner, inspectors may have to check many unimportant parts and pay less attention to important parts including the braking system.
　　　　　The NRA may be buried in piles of paper, overlooking a trouble with the important braking system. Inspecting unimportant parts very seriously can increase risks.
　　　　　Based on past experiences, reliability-centered maintenance has been implemented in the world. The RCM features an inspection focused on key parts with risks taken into account. The RCM approach has been developed for the aircraft industry and used for nuclear power plants outside Japan. In this sense, it may not be too much to say that overseas nuclear power plants are safer than those in Japan.
　　　　　The people hope for safe nuclear power plants. I would like the NRA to introduce the RCM approach giving full consideration to risks and make nuclear power plants in Japan as safe as in China and South Korea.

Contribution to the world through development of safety technologies
　　　　　Instead of recommending the back side of the rearview mirror to be checked, the NRA should study special sodium and FRB safety technologies and raise its skills at least to the Chinese level
　　　　　It is important for Japan to accumulate Monju FRB operation experiences and take a leading role in developing difficult sodium and FRB technologies. FRB development would help create a strategy for resources-poor Japan to become a technology-oriented country and allow this country to make global contributions.

Koji Okamoto is Professor and Head of Department Nuclear Professional School at the University of Tokyo.