- Japan is expected to start flushing 1.25 million tonnes of wastewater from the embattled Fukushima nuclear power plant into the Pacific Ocean this year
- It is a part of a $76-billion project to decommission the facility
- The idea, which experts and officials in Japan had floated in 2016, has been controversial for its suspected impact on the water, marine life, fishers’ livelihoods and other countries in the area.
Why is water a problem
- The water that the Japanese government wants to flush from the plant was used to cool the reactors, plus rainwater and groundwater.
- It contains radioactive isotopes from the damaged reactors and is thus itself radioactive.
Can’t the water be treated
- The Tokyo Electric Power Company (TEPCO), which operates the Fukushima facility, has said it has treated the water to remove most radioactive isotopes
- However, there is no known threshold below which radiation can be considered safe
- Another problem is that it hasn’t removed tritium from the water because this is very difficult to do. Tritium is easily absorbed by the bodies of living creatures and rapidly distributed via blood.
- There were other radionuclides in the water that TEPCO’s treatment procedure couldn’t entirely remove. These include isotopes of ruthenium and plutonium, which could persist for longer in the bodies of marine creatures and on the seafloor.
Other options with Japan
- The Japanese government can store the water for longer and then discharge it. This is because tritium’s half-life – the time it takes for its quantity to be halved through radioactive decay – is 12-13 years.
- The quantity of any other radioactive isotopes present in the water will also decrease in this time (each isotope has its own half-life).
- So at the time of discharge, the water could be less radioactive.
- But in 2020, authorities determined that flushing the water would be the way forward, over storage and vapourisation.
- In 2020, International Atomic Energy Agency (IAEA) officials also said the discharge would be technically feasible and would allow the timeline objective to be achieved.