Photo/Illutration Storage tanks on the grounds of the Fukushima No. 1 nuclear power plant hold large amounts of treated contaminated water. (Asahi Shimbun file photo)

To alleviate negative publicity, the government plans to quadruple the number of tritium-monitoring points in the ocean ahead of planned release of water accumulating at the crippled Fukushima No. 1 nuclear power plant.

Tokyo Electric Power Co. intends to discharge millions of tons of the treated water into the ocean from spring 2023. Fishermen and others have opposed the plan, saying the water release will reignite false rumors about radioactive seafood caught in the area.

On Feb. 9, the government agreed to intensify monitoring starting in spring to provide a comparative base for tritium levels in the water ahead of the actual release of the water from the Fukushima plant.

A panel of experts under the Environment Ministry gave the green light for the increased monitoring. The new measure will be included in a revised general monitoring plan the government will compile before the end of March.

The new plan will also be explained to officials of the International Atomic Energy Agency who will begin their evaluation of the domestic situation on Feb. 14.

TEPCO says the Advanced Liquid Processing System (ALPS) can remove almost all radioactive elements, but not tritium, from the contaminated water that is being stored at the nuclear plant.

There are now 12 monitoring points for tritium, but that number will be increased to about 50.

More than half of the points will be placed within 10 kilometers of the planned water release area because it is more difficult to determine the effect of the released water on tritium levels at locations beyond that distance.

In addition, new monitoring points will be set up off the southern coast of Miyagi Prefecture and the northern coast of Ibaraki Prefecture. For locations within a 50-km radius of the water release point, tritium monitoring will be conducted both on the ocean surface as well as from near the seabed.

While measurements will be taken four times a year, in principle, the number will be increased immediately after the contaminated water is first released.

Tritium measurements will also be conducted twice a year in four beaches close to the Fukushima nuclear plant.

TEPCO plans to strengthen its own monitoring of tritium in the water from April.

It will increase from seven to 10 the number of monitoring points within 2 km of the plant. The utility will also set up new monitoring points beyond a radius of 20 km while increasing the number of measurements taken at some points.

The treated water will also be diluted with a large amount of seawater so the level of tritium entering the ocean will be under one-40th of legal standards. The water will be released through an underwater tunnel that extends about 1 km off the coast.

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