Fukushima water disposal to be discharged over 40 years

The proposal to release water from the troubled Fukushima nuclear power plant into the ocean is robust enough to start, at least in the short term, according to an Australian radiation expert.

University of Adelaide Associate Professor Tony Hooker is a member of the five-person scientific advisory panel to the Pacific Islands Forum on the proposed disposal of 1.25 million tonnes of treated wastewater into the ocean.

He visited Fukushima in February, where he talked with the station’s operator TEPCO, the Japanese government, and the International Atomic Energy Agency, which is tasked with independently analysing the Japanese plans and scientific data.

“Whilst this disposal plan meets the scientific and regulatory requirements for the disposal of radiation into the sea, and no environmental or human health impacts are likely to be observed, there is the growing question regarding the use of the sea as a dumping ground when our oceans are already stressed and struggling,” Hooker says.

But the complex problems must be measured against each other considerations as well.

“There are concerns about the safety of storing this volume of water pending other earthquakes and/or tsunamis,” Hooker says.

Cosmos Explainer: Water release at Fukushima

“In addition, the Japanese also indicate the need to clear space for solid radioactive waste so that the reactors can be dismantled as part of the decommissioning process.

“This water is a combination of water used to cool the damaged reactors, groundwater contaminated following the earthquake, and tsunami as well as from rainwater captured on site.

“There comes a time when an Emergency Exposure situation transitions to a Planned Exposure situation. TEPCO and the Japanese government, I believe, have developed a robust plan to at least start disposing of water in the short term.

“And whilst its technically true that the 1.3 million tonnes of water planned for release from Fukushima into the Pacific Ocean will be radioactive, the level of radiation needs to be put into some context.”

It’s estimated no more than 500 tonnes of water will be released in any one day, but they will also be collecting water daily. Hooker says the release is expected to be completed over 40 years.

The water currently held in the tanks on the Fukushima site contains approximately 64 radionuclides. By using the Advanced Liquid Processing System (ALPS), 62 of the radionuclides are removed from the water, except for carbon-14 and the radionuclide of most concern, tritium.

Prior to disposal into the sea, this tritiated water is further diluted using sea water.

“All water is to be analysed by an independent third-party radiation laboratory for the presence and activity of radionuclides prior to any release,” Hooker says.

“One advantage of the ALPS is that the water can be further cleaned by repeating the ALPS process if it does not meet the regulatory requirements set out by the planned exposure radiation management plan.”

This plan states that any water to be released must be less than 1,500 Becquerel per litre (Becquerel or Bq is the unit measure for radioactivity), which is well below the recommended limit of 10,000 Bq/L set by the World Health Organisation for drinking water.

Hooker last travelled to Fukishima in February: “…it was snowing.”

“You can see that the Japanese are starting to re-develop areas outside of the no go zone such as shopping centres,” Hooker says.

“The direct area around the Fukushima Daiichi Power Plant, is still a no-go zone and within that area, you can still see damaged buildings/shops//homes from the Tsunami and subsequent evacuation.

“The NPP site itself is a hive of activity with many people working shifts to clean up the site (decommissioning) and surrounding areas.”