Fukushima nuclear meltdown

Six years after the meltdown

Six years after the Fukushima nuclear disaster, data suggests the plant is still leaking radioactive isotopes into the Pacific Ocean.

In September of 2013, a team of scientists from the Universitat Autonoma de Barcelona examined the levels of strontium and cesium in the coastal waters off Japan. It was found that the radioactive levels in seawater were 10 to 100 times higher than before the disaster struck – indicating that water discharging into the Pacific Ocean still contained strontium and cesium isotopes.

A new study published in Environmental Science and Technology utilized this data, and detected noteworthy amounts of 90Sr, 134 and 137Cs; results that are in total alignment with TEPCO’s monitoring data.  These outcomes clearly underpin the necessity of constant monitoring of these radionuclides in the Pacific Ocean. [1] [2]

In 2015 “Tepco reported the highest-ever readings of strontium-90 outside of the Fukushima plant ports. The readings were 1,000,000 Bq/m3 of strontium-90 at two locations near water intakes for Reactors 3 and 4. Tepco has not been able to explain the spike in readings. The prior highest readings were 700,000 Bq/m3.” [3]

Adverse health effects of both Cesium and Strontium are well established. Inside the body, Strontium-90 mimics calcium and is quickly absorbed by the bones – leading to deposit build-up causing constant and considerable damage. It is also a possible carcinogen, with the capacity to cause DNA damage and increase the risk of developing cancer.

Cesium, on the other hand, can cause heavy damage to the heart, as it mimics potassium. Professor Yuri Bandazhevsky found that children contaminated with 50Bq/kg Cs -137 suffered irreversible heart damage [4]. Radioactive cesium can just as easily damage other organs including the kidney, liver, brain and the endocrine system. What is even more dangerous is that it acts very quickly in the body.

Many questions still loom

Even after six years, people are in the dark about the magnitude of the damage caused by the breakdown of the Fukushima reactors. For one, TEPCO, the Tokyo Electric Power Company, is unwilling to share information. Citizens are concerned. People who evacuated are scared to come back for fear of lingering radiation. Independent scientists and research groups are raising questions. There is a widespread feeling of suspicion that many important aspects of this catastrophe are still ‘under wraps’. Scientists suspect that the concerned authorities are going to the extent of discouraging research that could bring the truth into open.

Lending credibility to widespread scepticism, it was not until February of 2016 that TEPCO admitted “it had waited for two months after the accident before announcing the meltdowns—which possibly delayed evacuations and endangered lives.” [5]

Amid all the chaos, the Japanese government has reopened some of the nuclear reactors. And this when more than 1,100 square kilometres of villages, forests and mountains still remain uninhabitable. While Japan’s decision to re-start the reactor has been justified owing to the enormous cost of importing it’s fossil fuel energy and escalating CO2 emissions, many feel that the option of utilizing renewable energy sources to generate the required energy has not been fully explored.

According to Ai Kashiwagi, from Greenpeace Japan, the country hasn’t learned its lessons, noting that “In Japan, there’s no safe place for nuclear reactors. What we have seen at Fukushima Daiichi can happen at another reactor.” [6]

The risks that still remain

Although Tepco has since made significant efforts in cleaning up the site, not all seems to be going well. A constant flow of water is required to keep the cores of the melted reactors cool. However, the containment vessels leak, thus compelling TEPCO to collect the radio-contaminated water that can leach out into the sea; and also to hold the rainwater that comes flowing down the hillside and the adjoining zones. All this water has been accumulated into storage tanks.

David Wagner (President, David Wagner & Company) writes in The Huffington Post, “there is no greater risk to Japan at present than the hundreds of tanks containing highly radioactive waste water sitting on the plant site a few meters from the ocean – the same site where only 6 years ago waves reaching 40 meters smashed up along the coast.”

Any natural disaster of the Fukushima scale has the full potential to break-down these storage tanks, making the contamination issue even more deadly. Compounding the issue is the fact that these tanks leak water from time to time.

While TEPCO is meticulously removing radioactive cesium and strontium before the water is eventually directed to the tanks, the water still contains high levels of radioactive tritium; something that is very difficult and expensive to remove. At a concentration higher than 1,500 becquerels per liter – which is way higher than the drinking water level agreed by the World Health Organization as safe – the tritium mixed water it is not safe to be discharged into the ocean.

Tritium is a radioactive isotope of hydrogen, and just like hydrogen, tritium attaches itself to oxygen and makes tritiated water. Whether drinking water containing tritium poses serious threat is a question that is still being examined. However, existing data suggest that tritium may cause cancer [7].

What’s more, the whimsical initiative to build an underground ice wall, at a staggering cost of some $320 million and designed to prevent the water from reaching the ocean, was widely touted as a highly controversial and complex solution, as reported in an article by the New York Times.   

An article in Scientific American, dives deeper into these dangers. It reports that TEPCO has no estimation on the amount of debris lying in the reactor. Molten fuel, which melted through steel vessels, is yet to be confirmed as having been located. With Japan having no permanent repository to store the nuclear debris, there is no clarity whatsoever as to where the deadly nuclear waste will eventually end up. And on top of everything, it looks like the decaying of radionuclides might take around 50 years before the site will be deemed fully clean. In addition, there is a heavy build-up of solid debris too. The clean-up efforts of the evacuated area has resulted in the “millions of bags of contaminated topsoil and debris”, to quote the article.

For now, Fukushima – even after six years of painstaking clean-up effort – has remained a wound that is not ready to heal. And it is definitely not easy to come around from a nuclear catastrophe of this magnitude. It will take generations to overcome the loss and pain.


  1. Continuous leaking of radioactive strontium, cesium from Fukushima to the ocean. March 2016.
  2. Maxi Castrillejo, Núria Casacuberta, Crystaline F. Breier, Steven M. Pike, Pere Masqué, Ken O. Buesseler. Reassessment of90Sr,137Cs, and134Cs in the Coast off Japan Derived from the Fukushima Dai-ichi Nuclear Accident. Environmental Science & Technology, 2016; 50 (1): 173 DOI: 10.1021/acs.est.5b03903
  3. Robert Hunziker. June 2015. Is Fukushima Getting Worse? Counter Punch.
  4. Senior Scientist: Irreversible heart damage for children with 50 Bq/kg of Cs-137. ENE News. 2012
  5. Madhusree Mukerjee. Crippled Fukushima Reactors Are Still a Danger. 5 Years after the Accident. Scientific American. March 8, 2016
  6. Will Ripley, Junko Ogura and James Griffiths. Fukushima: Five years after Japan’s worst nuclear disaster. CNN. March 11, 2016
  7. David Biello. Is Radioactive Hydrogen in Drinking Water a Cancer Threat? Scientific American. February 8, 2014.