A memorandum of cooperation has been signed between the UK and Japan for partnership on fusion energy - as companies in the two countries announce new collaborations.

Japanese utility Tokyo Electric Power Company announced that it has begun loading fuel assemblies into the core of unit 6 at its Kashiwazaki-Kariwa nuclear power plant ahead of its restart. The unit looks likely to be restarted before unit 7, into which fuel was loaded last year.

Japan's Kyushu Electric Power Co says it is currently considering designs including innovative light-water reactors, small modular reactors and high-temperature gas reactors as it aims to develop a "next-generation innovative reactor".

The Nuclear Regulation Authority has approved a draft report that concludes unit 3 of the Tomari nuclear power plant on Japan's northern Hokkaido island meets the new regulatory safety standards, a prerequisite for its restart.

The Japan Atomic Energy Agency has developed what it says is the world's first "uranium rechargeable battery" and that tests have verified its performance in charging and discharging. Meanwhile, South Korean researchers have developed a prototype betavoltaic battery powered by the carbon-14 isotope.

Japanese utility Chubu Electric Power Company announced it has removed the upper lid of the pressure vessel of unit 2 at its Hamaoka nuclear power plant in Shizuoka prefecture as it begins to dismantle the reactor. It becomes the first commercial power reactor in Japan to enter dismantling.

Tests carried out on high burnup fast reactor fuel as part of a collaboration between the USA and Japan are the first of their kind carried out in more than 20 years, and will provide crucial new data to support future fuel development and qualification.

Japan's Fukushima Institute for Research, Education and Innovation and the United Kingdom Atomic Energy Authority have signed a memorandum of cooperation on joint research in robotics and autonomous systems, including applications in nuclear decommissioning.

During his latest trip to Japan, International Atomic Energy Agency Director General Rafael Mariano Grossi assisted in collecting seawater samples near the damaged Fukushima Daiichi nuclear power plant for analysis.