Tokyo must adopt an approach of "sincerity and responsibility and take practical actions" to address its excessive storage of nuclear materials and increasing imbalance between supply and demand, Beijing said, following a report released by think-tanks.

The report, which was drawn up by the China Arms Control and Disarmament Association (CACDA) and the China Institute of Nuclear Information and Economics, highlighted problems and risks in relation to Tokyo's large inventory.

The report said that the Japanese government has yet to answer questions on why it stores large amounts of nuclear materials and how it will solve the serious imbalance of the supply and demand situation of these materials.

Japan's large amount of sensitive nuclear materials far exceeds its actual needs and brings safety and proliferation risks, the Foreign Ministry's spokesperson Hua Chunying said. These issues have already aroused concerns and questions by countries and international groups that specialize in nuclear issues, he added.

Chen Kai, secretary-general of CACDA, said Japan is the only country among non-nuclear weapon states to possess commercial-scale reprocessing and enriching capability at the same time, which means it is capable of developing nuclear weapons.

According to the International Atomic Energy Agency (IAEA), Japan currently has 47.8 tons of separated plutonium, 10.8 tons of which is in Japan, Chen said, (the rest is stored in France and the United Kingdom). The Japanese government promised in the 1990s it would have "no residual plutonium", however, after 20 years, its inventory of separated plutonium doubled, he added.

Chen suggested that the plutonium Japan stored in the UK and France could be transferred to those countries permanently in a commercial deal.

"It would undoubtedly be of great significance and set a good example," Chen added.

Regarding the plutonium stored in Japan, the report suggested that besides reserving a certain amount for future use, the rest should be entrusted to the IAEA to be actually frozen and Japan should give priority to using MOX fuel to restart its nuclear power plant in order to consume the existing plutonium inventory as soon as possible.