China on Thursday called for action from Japan to defuse concerns over its excess of nuclear materials as both Chinese and U.S. think tanks expressed worry in recent reports.
"The international community has always been concerned about Japan's stockpile of enriched uranium and the risks relating to nuclear proliferation and safety," Foreign Ministry spokesperson Hua Chunying said.
"The reports suggest there are ways to resolve the surplus nuclear material issue," she said at a regular news briefing, calling on Japan to be responsible and act to address the international community's concerns.
The stockpile puts Japan, its neighbors and the world at risk, a joint study by China Arms Control and Disarmament Association and the China Institute of Nuclear Information and Economics said on Friday.
"If, in future, a different country started to stockpile -- could be enriched uranium, it could be plutonium -- that country could cite Japan as a precedent," said James Acton, author of a new report on Japan's reprocessing policy at the Carnegie Endowment for International Peace think tank.
The Chinese study suggests Japan should make a rational plan for its nuclear consumption and address the imbalance, while ensuring the safety and security of these materials.
Citing the latest data from the Japanese government submitted to the International Atomic Energy Agency (IAEA), the Chinese study found Japan has 47.8 tonnes of highly sensitive separated plutonium, 10.8 tonnes of which are stored in Japan, enough to make 1,350 nuclear warheads.