Fukushima Wastewater Contaminants at Risk of Being Released into the Ocean

Almost a decade after the Fukushima Dai-ichi Nuclear Power Plant in Japan was devastated by the tsunami and Tohoku-Aoki earthquake, and wastewater contaminants are at risk of being released into the ocean. The disaster released unprecedented radioactivity to the sea.

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Current Status

Since then, radiation levels already reached a safe level in all regions except for those most closely located to the plant. Now, various seafood and fishes from the waters around the plant, except for a limited area, are well within Japan's strict radioactive contamination limits.

However, a new danger that has emerged is becoming a growing hazard every day. This involves the storage tanks, containing contaminated wastewater, located on the land surrounding the powerplant.

An Assessment of the Situation

Published last August 7 in Science, the article looked at several radioactive elements within the tanks. It suggested that more has to be done to better understand the risks of releasing tank wastewater on the ocean.

According to author and Woods Hole Oceanographic Institution marine chemist Ken Buesseler, observation of the area was made for more than nine years, as radioactive cesium levels declined in the water and Pacific marine life.

He says that some radioactive contaminants are still contained in the tanks and even pose a concern. These have not been seen in huge amounts in the 2011 disaster. Most importantly, these do not act in the same manner in the ocean.

Buesseler has been monitoring and studying the radiation's spread from the power plant into the Pacific and across the ocean since 2011. Last June 2011, he led a scientific team in conducting an international research cruise, the first of its kind, on cesium-134 and cesium-137's early pathways when they reached Kuroshio, a powerful current off Japan's coast. The reactors produce the radioactive cesium isotopes.

Buesseler has also created a citizen scientists' network in Canada and the United States to help monitor arriving radioactive material on North America's Pacific coast and track their movements.

Current Concerns

His concerns now lie with the tanks, which number over 1,000, on the power plant the grounds which are being filled with cooling water and groundwater, which have been contaminated with contact from the reactors and containment buildings.

Sophisticated processes of cleaning removed many of the radioactive isotopes. Efforts in diverting the groundwater flow around these reactors significantly reduced collected contaminated water to lower than 200 tons each day.

However, some estimates say that the tanks will be filled soon, which led Japanese officials to suggest that treated water be released to the ocean to free space for additional wastewater.

Tritium has the highest level in the wastewater. It is a hydrogen isotope nearly impossible to eliminate because it becomes part of the water itself. However, it has a short half-life and is not easily absorbed by marine life and sea sediments. It also produces beta particles that do not do as much damage.

Treated wastewater also has cobalt-60, strontium-90, and carbon-14. Their decay takes longer and has higher affinities with marine organisms and sea sediments. They cause potentially more prolonged and more complex hazards.

Possible Courses of Action

Buesseler said that focusing on tritium ignores the other isotopes. He says the additional contaminants must be cleaned up to solve it, after which new plans must be made on whatever remains. Ocean release must involve independent and proper tracking of pollutants. The ocean's health, those of countless people depend on it.

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