BEIJING, October 28. /TASS/. Japan possesses more than 40 metric tons of plutonium, theoretically enough to produce several thousand nuclear warheads, Secretary General of the China Arms Control and Disarmament Association (CACDA) Dai Huaicheng told TASS.
He pointed out that according to the Japanese authorities, the country possessed 44.4 tons of separated plutonium at the end of 2024, including 8.6 tons stored domestically and 35.8 tons held overseas. In addition, Japan’s stocks of spent nuclear fuel contain about 191 tons of unseparated plutonium.
"The latest report from the Japan Atomic Energy Commission, published in August 2026, says that the total amount of separated plutonium remained at about 44.4 tons at the end of 2025, with 9.9 tons stored in the country and about 34.5 tons held abroad, as the size of the stocks remained vast," Dai said.
"What does this mean? Making a simple nuclear warhead typically requires only a few kilograms of weapons-grade plutonium. According to open sources, Japan’s 44.4 tons of separated plutonium would be enough to manufacture several thousand nuclear warheads," the expert pointed out.
Dai also said that the Japanese authorities justified the country’s substantial plutonium stockpiles by citing plans to use the material as fuel for nuclear power plants. However, this remains a cause for concern amid statements by some Japanese politicians advocating the acquisition of nuclear weapons, the expert added.
"Although most of Japan’s plutonium is reactor-grade, it’s not entirely impossible to use it in nuclear devices. Notably, Japan has the technology and processing facilities needed to separate weapons-grade plutonium, making the distinction between civilian and military use extremely blurred," the expert concluded.