Electronic security seals installed by the International Atomic Energy Agency (IAEA) and the Nuclear Regulation Authority (NRA) at the nuclear fuel reprocessing plant (located in Rokkasho, Aomori Prefecture) operated by the Japan Nuclear Fuel Ltd. (JNFL) were discovered on Aug. 5 to have been broken. This was revealed on Sept. 3 when the Nuclear Regulatory Agency provided a written answer to an inquiry from Lower House member Yasufumi Fujino of the Japanese Communist Party. According to the agency, the NRA will investigate the incident and issue a report by mid-September.

The electronic seals are installed in accordance with the Nuclear Reactor Regulation Law for the purpose of monitoring nuclear materials such as uranium and plutonium to prevent them from being used to develop nuclear weapons. According to the agency, the seals had been installed on a box containing data transmission cables for monitoring plutonium to prevent the data from being tampered with. The IAEA and the NRA have already replaced the broken seals and ascertained that the cables inside were not damaged.

In the past, the JNFL has experienced similar incidents involving broken seals, including one discovered in March 2020 at a uranium enrichment plant. When a seal installed by the NRA there was found to be broken, the regulatory agency issued a stern oral warning. The latest incident involving broken seals was the seventh one in the past 12 years to occur at a JNFL facility and the fourth one involving IAEA seals.

Plutonium is used to develop nuclear weapons, and it is internationally required to be placed under strict management. The NRA approved the Rokkasho plant’s basic safety measures in July and the facility is slated for completion in 2022. (Slightly Abridged.)