How does chemistry contribute to circular economy in nuclear energy systems to make them more sustainable and ecological?

While one should be aware that its zero CO 2 emission is actually achievable only when electric power is generated, nuclear power is one of the most viable and proven "carbon-free" energy sources to provide baseload electricity to the current energy-demanding society. Even after the power generation, the major part of spent nuclear fuels still consists of recyclable nuclear fuel materials such as U and Pu, promising circular economy of nuclear energy systems in principle. However, actual situations are not very simple due to the following issues: (1) resource security of nuclear fuel materials, (2) issues of depleted uranium, and (3) treatment and disposal of high-level radioactive wastes. In this Perspective, I discussed how chemistry can contribute to resolving these problems and what task academic research in fundamental chemistry should take on there.