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Japan’s Expert Panel Agrees That Dumping Radioactive Water Into The Ocean Is Best

This article is more than 4 years old.

Yesterday, an expert panel released a draft report recommending that the Japanese government allow Tokyo Electric Power Company to release radioactive water from its crippled Fukushima nuclear power plants into the ocean.

Either that or evaporate it into the atmosphere. Both are fine, especially since a gallon of this water is as radioactive as a bag of potato chips.

The Fukushima water is stored on-site in almost a thousand large tanks. Tritium is the primary radioactive material in the water, and is the only constituent in the water that could pose a hazard.

Evaporation was proven to be effective and safe after the 1979 Three Mile Island accident, and we know releasing it to the ocean is also effective and safe, as we routinely release tritiated water from existing nuclear power plants around the world all the time.

That’s because the unique characteristics of tritium, which is the least radioactive and least harmful of all radioactive elements, make it ideal to put into seawater.

As discussed on previous occasions, tritium likes to be in water, not in tissue, so it cannot concentrate up the food chain - it dilutes up the food chain. The biological half-life of tritium in fish and marine life is less than 2 days, and the dilution in seawater is too rapid for any significant dose to get back to any people or any other organism.

A small amount of tritium is formed in nuclear weapons production and testing, and an even smaller amount comes from nuclear power plants. 99.9999999% of tritium on Earth is formed by natural atmospheric processes, as has occurred for billions of years.

Tritium is the mildly radioactive isotope of hydrogen that has two neutrons and one proton, with radioactivity so low that no environmental or human problems have ever come from it, even though it is a common radioactive element in the environment.

Tritium is just assumed to be carcinogenic to humans at extremely high levels, although that claim is only hypothetical. I suppose you could concentrate it in the lab and inject it into someone to cause death, or have some strange bomb-making scenario go awry, but it couldn’t happen naturally, and certainly not from nuclear waste or anything that could happen in Japan.

Those of us who understand the problem and the science have suggested for years that we should slowly release the tritium-contaminated water into the Pacific Ocean over about a ten-year period.

It’s very difficult for the extremely low-energy beta from tritium to get through the water, cell walls and other materials in between the radionuclide and any DNA. The energy in the slow-moving beta from tritium mostly gets dispersed within the electron clouds of other molecules through inelastic collisions and the Bremsstrahlung effect. This turns the kinetic energy of the beta emission into electromagnetic non-ionizing energy.

In the end, it is impossible to get a significant radiation dose from tritium, unlike any other radionuclide. It exits the body and is diluted too quickly.

Even more important, more tritium is already in the atmosphere from natural processes than ever has been, or will be, released from commercial reactors. Cosmic rays produce four million curies worth of tritium every year (150,000,000,000,000,000 Bq) in the upper atmosphere, much of which rains out into surface waters that we end up drinking.

Typical cosmogenic tritium concentrations in seawater are about 700 Bq/m3 (19 pCi/L), greater than what is in most of these Fukushima tanks.

These amounts of natural tritium are billions of times greater than what would be slowly released from these tanks at Fukushima. Since there’s been no health or environmental effects from any of these larger sources, it’s hard to get excited about dumping such a tiny amount from Fukushima into the ocean.

Besides, there are 16,280,000,000,000,000,000,000 Bq of naturally-occuring potassium-40, rubidium-87 and many more radionuclides already in the world’s oceans. So the fish are swimming in plenty of natural radioactive material anyway, more than this Fukushima water could ever provide.

Putting this water into the ocean is without doubt the best way to get rid of it. Concentrating it and containerizing it actually causes more of a potential hazard to people and the environment. And is very, very expensive with no benefit.

Unfortunately, the idea of releasing radioactivity of any sort makes most people cringe. But that’s the problem, only the perception of tritium is bad, not the reality.

The health risks of tritium-contaminated water are so low that all the countries of the world have no idea what regulatory limits to put on it. The United States has set 740 Bq/L for drinking water limits while Australia set a whopping 76,103 Bq/L as their limit. But these limits are just taken out of thin air - they’re not health or science-based.

Fishermen and residents fear possible health effects from releasing the radioactive water and also fear another hit to the region's image as well as to their fishing industry. But their fish will still test negative with respect to food radiation limits and their packaged fish sold at market would still carry the official “safe” stickers.

So after nine years, Japan seems to be taking a small step toward deciding what to do with the water and appears willing to listen to experts. Tokyo Electric Power Company has already treated this water to remove all of the 62 radioactive elements it contains, except for tritium, down to safe levels. 

There is some pushback on this idea to release the water to the ocean, as you would expect. “We should put Fukushima's recovery before anything else," said Takami Morita at the National Research Institute of Fisheries Science. “Local fishermen and residents cannot accept a release of the water unless Fukushima's recovery makes more progress.”

Morita said demand for Fukushima fish has only recovered to less than one-fifth of levels before the accident, even though fish from the area meet all safety standards. 

The report acknowledges the water releases would harm industries that still face reluctant consumers despite diligent safety checks. It recommends reinforcing monitoring of tritium levels and food safety checks in order to address consumer concerns. 

If they do release this water, then this particular problem will be gone and things can move forward. Just holding on to the water means it will be around for decades, preventing clean-up of the site and making it sound like it’s a big deal when it isn’t.

The expert panel will submit the final proposal to the government in coming weeks, after which the government will decide whether, when and how the water should be released. 

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