Archive · 20 Aug 2026
China Raises Nuclear Concerns Over Japan’s Plutonium Stockpile
China says Japan has a very large amount of plutonium from nuclear energy activities.
A Chinese ambassador said the separated plutonium could theoretically make about 5,500 nuclear warheads.
He also said Japan has more plutonium in spent nuclear fuel that has not yet been extracted.
China argues that Japan’s technology and growing military capabilities could let it change its defence policy quickly.
Japan says it follows rules that prohibit possessing, producing, or introducing nuclear weapons.
Japan also says its nuclear research and energy use are only for peaceful purposes.
The two countries are arguing about Japan’s military expansion and China’s military activities.
The plutonium figures have appeared in Chinese criticism before.
The claims describe a theoretical capability, not a statement that Japan is building nuclear weapons.
China’s ambassador to Russia said Japan held 44.4 tonnes of separated plutonium at the end of 2024.
Zhang Hanhui claimed the stockpile could theoretically produce about 5,500 nuclear warheads.
He said Japanese spent-fuel facilities contained another 191 tonnes of unextracted plutonium.
Japan reaffirmed its Three Non-Nuclear Principles and said its nuclear activities are exclusively peaceful.
The dispute comes amid worsening China-Japan relations and scrutiny of Japan’s expanding defence capabilities.
- Who
- Chinese Ambassador to Russia Zhang Hanhui raised the claim; Japan’s ambassador Tomiko Ichikawa rejected it.
- What
- China claimed Japan’s plutonium stockpile could theoretically support about 5,500 nuclear warheads, while Japan reaffirmed its non-nuclear commitments.
- When
- The cited stockpile was measured at the end of 2024; related Chinese criticism appeared in March 2026 and Japan responded in April 2026.
- Where
- The latest claim was published by Russia’s state-run TASS news agency; Japan’s response came at a Nuclear Non-Proliferation Treaty review conference.
- Why
- The remarks came amid worsening China-Japan relations, Japan’s defence expansion, and mutual concerns about the other country’s military capabilities.
China’s Concerns
Japan’s Position
Nuclear potential
China’s Concerns
China says Japan’s separated plutonium and spent-fuel technology could theoretically enable a rapid transformation into a nuclear power if Tokyo chose to do so.
Japan’s Position
Japan says the introduction of nuclear weapons is not permitted under its Three Non-Nuclear Principles and that its nuclear activities are exclusively peaceful.
Defence expansion
China’s Concerns
China argues that Japan’s military expansion, advanced weapons development, and defence-industry activity have moved beyond a purely defensive posture.
Japan’s Position
Japan has expressed concern about China’s military activities, particularly around Taiwan, and has criticised what it describes as a lack of transparency over China’s defence spending and capabilities.
- Separated plutonium
- Japan reportedly had 44.4 tonnes at the end of 2024.
- Theoretical warhead estimate
- China’s ambassador said the stockpile could support around 5,500 nuclear warheads.
- Unextracted plutonium
- Japan’s spent-fuel storage facilities reportedly contained another 191 tonnes.
- Japan’s stated policy
- The Three Non-Nuclear Principles prohibit possessing, producing, or allowing the introduction of nuclear weapons.
- Japan’s nuclear-use position
- Japan said its research, development, and use of nuclear energy are exclusively peaceful.
- Earlier Chinese report
- PLA Daily cited the same 44.4-tonne figure in March 2026.
- Defence developments cited
- Chinese criticism referred to Japan’s long-range weapons, missile defence, advanced military technology, and cooperation with the United States.