The ALPS-treated water is water purified of radioactive substances, other than tritium, to levels below regulatory standards. It is to be further diluted with seawater to a level of 1,500 Bq/l, one-fortieth the regulatory limit of 60,000 Bq/l, before being released into the sea.

There are four facilities involved in handling the treated water, dealing with the following, respectively: (1) measurement and confirmation, (2) transport, (3) dilution, and (4) release. The measurement and confirmation facility received a certificate of completion last March. Certificates issued by the NRA on July 7 covered pre-use inspections of the remaining transport, dilution, and release facilities.

In July 2022, the Tokyo Electric Power Co. (TEPCO) received permission from the NRA to make changes to the relevant reactor installations, with installation work beginning in August. On April 26 of this year, then, it completed a discharge tunnel (about 1km long), with all facilities fully completed by June 26. The NRA began its remaining pre-use inspections on June 30.

In January of this year, the interministerial council for the handling of the ALPS-treated water presented its expectations, as follows: after the complete installation of the offshore-release facilities, the NRA would start pre-use inspections and the International Atomic Energy Agency (IAEA) would make a comprehensive report on the matter, with offshore release starting sometime in the spring or summer.

On July 4, the IAEA delivered its comprehensive report on safety reviews regarding the ALPS-treated water to the Japanese government. With the conclusion now of the NRA’s pre-use inspections, preparations for offshore release have been completed in respect of the facilities as well as safety.

TEPCO released the following comment: “We will endeavor to effectively maintain and manage the dilution and discharge facilities for the ALPS-treated water, and other related facilities. To properly operate the facilities, we will continue to work proactively to enhance the quality of all operations involved in safety at the site, including training in operations, emergency responses, and more.”