5.5t Contaminated Water Leak Occurs at Fukushima Nuclear Plant...Possibility of Seepage into Soil Raised

Contaminated water exposure occurred at a contaminated water purification device within the Fukushima Nuclear Power Plant in Japan.

Fukushima Nuclear Power Plant Contaminated Water Storage Tank
[Image source=Yonhap News]

The Asahi Shimbun reported on the 7th that Tokyo Electric Power Company (TEPCO) announced a leak of 5.5 tons of contaminated water from a purification device at the Fukushima Daiichi Nuclear Power Plant.

According to the report, around 8:55 a.m. that day, a worker discovered contaminated water leaking from an exhaust vent on the outer wall of the high-temperature incinerator building within the nuclear power plant. The exhaust vent was created to release hydrogen generated by the contaminated water purification device, which removes radioactive substances such as cesium and strontium contained in the contaminated water, to the outside of the building.

At the time of the accident, the purification device was stopped. In preparation for inspection, they were flushing the pipes with regular water to remove contamination. However, a valve that should have been closed was accidentally opened, causing the remaining contaminated water and cleaning water in the pipes to mix and flow out through the exhaust vent. TEPCO believes that the leaked contaminated water may have seeped into the soil outside the building and plans to collect this soil.

TEPCO estimated the total amount of leaked contaminated water at 5.5 tons, with the total amount of leaked radioactive material estimated at 22 billion becquerels (Bq). However, they stated that there was no impact outside the nuclear power plant site. The Asahi Shimbun reported, "There was no significant change in the concentration of radioactive substances in the drainage channel closest to the site, and no external impact such as leakage into the sea has been confirmed."

The Fukushima Daiichi Nuclear Power Plant currently passes contaminated water through a purification device first, then removes most radioactive substances with the Advanced Liquid Processing System (ALPS) before storing it in tanks. Previously, in October last year, two subcontractor employees of TEPCO were sprayed with liquid containing radioactive material when a hose came off while cleaning ALPS pipes without wearing protective equipment. Then, in December, a male employee in his 20s from a cooperating company working on decommissioning was contaminated on his facial area with radioactive material, and accidents have continued.