Japan's Fukushima Polluted Water Discharge Policy Before Confirmation of Tritium Measurement Results

The Mainichi Shimbun reported that Tokyo Electric Power, the operator of Japan's Fukushima No. 1 nuclear power plant, plans to dilute contaminated water stored in storage tanks inside the nuclear power plant site with seawater and then release it into the ocean without checking the results of the tritium concentration measurement, the Mainichi Shimbun reported.

It takes 12 hours to a day for the measurement results to come out, since there is no place to store the contaminated water diluted with seawater in the meantime.

According to Mainichi, the contaminated water in the storage tank contains 64 types of radioactive substances, and 70% of the stored contaminated water has a concentration of radioactive substances other than tritium that exceeds the standards of the Japanese government.

Accordingly, the Japanese government plans to reduce the concentration of radioactive materials below the standard level by using a multi-nuclide removal facility, but tritium is technically impossible to remove even with this facility.

Therefore, in order to lower the tritium concentration to less than 1,500 becquerels per liter, which is 1/4 of the Japanese government standard, the contaminated water is diluted 100 times with seawater and discharged into the sea.

TEPCO decided to measure the tritium concentration before dilution with seawater, and calculate the amount of seawater required for dilution based on the result.

We plan to measure the concentration of tritium by regularly collecting a certain amount from the discharge port while discharging contaminated water diluted with seawater as it is.

The problem is that even after dilution with seawater, even if the tritium concentration is more than 1,500 becquerels, the measurement result comes out after 12 hours to a day, so the contaminated water continues to be discharged into the sea in the meantime.

In response, Mainichi said, Reiko Hachisuka, a member of the Japan Atomic Energy Regulatory Commission's Fukushima Daiichi Nuclear Power Plant decommissioning review committee, suggested, "If possible, check the tritium concentration and send it to the sea."

TEPCO plans to submit to the Nuclear Regulatory Commission an implementation plan in the near future, including the design and procedure for discharging facilities to discharge contaminated water into the sea in the next two years. 

(Photo = Yonhap News)