Fukushima Nuclear Disaster

What’s in today’s article?

• Why in news?
• What is Fukushima nuclear disaster?
• News Summary: Fukushima nuclear plant will start releasing treated radioactive water to sea
• What does Japanese government want?
• What this move of Japanese govt is being opposed?
• What are Japan’s other options?
• What does the experts say on this step?

 

Why in news?

• Japan said that it will start releasing more than 1 million metric tonnes of treated radioactive water from the wrecked Fukushima nuclear power plant on Aug 24.
• This has been termed as a controversial step. However, the government says it is essential to clean up the plant facility that had reactor meltdowns 12 years ago.
  • As per the govt, the release of the water is a key step in the plant decommissioning and Fukushima prefecture’s recovery from the March 11, 2011, earthquake and tsunami disaster.

 

Fukushima nuclear disaster

• In March 2011, after a magnitude 9 earthquake, a tsunami flooded the Fukushima Daiichi nuclear power plant in Okuma and damaged its diesel generators.
• The loss of power suspended coolant supply to reactors at the facility; the tsunami also disabled backup systems. This led to Fukushima disaster.
• Soon, radioactive materials leaked from reactor pressure vessels, exploded in the facility’s upper levels, and exposed themselves to the ambient air, water, soil, and local population.
• Winds also carried radioactive material thrown up into the air into the Pacific.
• Since then, the power plant and its surrounding land have been uninhabitable.

 

News Summary: Fukushima nuclear plant will start releasing treated radioactive water to sea

What does Japanese government want?

• 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.

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• Japan has said that it will release this water into the Pacific Ocean over the next 30 years.
  • Nuclear plants around the world regularly release water containing trace amounts of radionuclides into large waterbodies.
• For this, water is being treated to remove most radioactive isotopes. This water will be far above safety standards.

 

Why this move of Japanese govt is being opposed?

• No known threshold
  • Japanese officials claim that the water will be treated before its release. However, experts claim that there is no known threshold below which radiation can be considered safe.
  • Any discharge of radioactive materials will increase the risk of cancer and other known health impacts to those who are exposed.
• Difficult to remove tritium from the water
  • Removing tritium from the water is a very difficult task.
    • tritium (T, or 3H) is the isotope of hydrogen with atomic weight of approximately 3.
  • But removal of tritium is necessary as it is easily absorbed by the bodies of living beings and rapidly distributed via blood.
• Impact on marine lives and livelihoods of the fisherfolk in the region
  • Experts expect the affected water to poison the fish.
  • South Korea banned seafood imported from around Fukushima, to Japan’s displeasure, from 2013.
• Impact on Pacific Ocean
  • There are concerns about the waterbody as well as the region.
    • China, South Korea, Taiwan and Pacific Islands Forum have expressed concerns over this.
  • Researchers across the world have also called for more studies to understand the precise composition of each tank before it is flushed.

 

What are Japan’s other options?

• 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.
• So, at the time of discharge, the water could be less radioactive.

 

What does the experts say on this step?

• The International Atomic Energy Agency in a final report in July concluded that the release, if conducted as designed, will cause negligible impact on the environment and human health.
• Scientists generally support the IAEA view, but some say long-term impact of the low-dose radioactivity that remains in the water needs attention.

 

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Q1) How did the Fukushima accident happen? 

An earthquake and tsunami led to power loss in the Fukushima Daiichi plant. Without power, the cooling systems failed in three reactors, and their cores subsequently overheated.

 

Q2) What is tritium?

Tritium is a radioactive isotope of hydrogen, denoted by the symbol "T" or "³H." It is the rarest and heaviest naturally occurring isotope of hydrogen. Tritium has one proton and two neutrons in its nucleus, whereas the most common form of hydrogen, known as protium, has only one proton and no neutrons.

 

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Source: Fukushima nuclear plant will start releasing treated radioactive water to sea as early as August 24 | Indian Express | BBC