Tag Archives: fukushima fisheries

A Huge Headache: the Radioactive Water at Fukushima

What to do with the enormous amount of radioactive  water, which grows by around 150 tons a day at Fukushima, is a thorny question, with controversy surrounding a long-standing proposal to discharge it into the sea, after extensive decontamination.  The water comes from several different sources: Some is used for cooling at the plant, which suffered a meltdown after it was hit by a tsunami triggered by a massive earthquake in March 2011.  Groundwater that seeps into the plant daily, along with rainwater, add to the problem.

A thousand, towering tanks have now replaced many of the cherry trees that once dotted the plant’s ground. Each can hold 1,200 tons, and most of them are already full.  “We will build more on the site until the end of 2020, and we think all the tanks will be full by around the summer of 2022,” said Junichi Matsumoto, an official with the unit of plant operator TEPCO in charge of dismantling the site.

TEPCO has been struggling with the problem for years, taking various measures to limit the amount of groundwater entering the site.  There is also an extensive pumping and filtration system, that each day brings up tons of newly contaminated water and filters out as many of the radioactive elements as possible.

The hangar where the decontamination system runs is designated “Zone Y” — a danger zone requiring special protections.  All those entering must wear elaborate protection: a full body suit, three layers of socks, three layers of gloves, a double cap topped by a helmet, a vest with a pocket carrying a dosimeter, a full-face respirator mask and special shoes.  Most of the outfit has to burned after use.

“The machinery filters contain radionuclides, so you have to be very protected here, just like with the buildings where the reactors are,” explained TEPCO risk communicator Katsutoshi Oyama.  TEPCO has been filtering newly contaminated water for years, but much of it needs to go through the process again because early versions of the filtration process did not fully remove some dangerous radioactive elements, including strontium 90.

The current process is more effective, removing or reducing around 60 radionuclides to levels accepted by the International Atomic Energy Agency (IAEA) for water being discharged.  But there is one that remains, which cannot be removed with the current technology: tritium.

Tritium is naturally present in the environment, and has also been discharged in its artificial form into the environment by the nuclear industry around the world.  There is little evidence that it causes harm to humans except in very high concentrations and the IAEA argues that properly filtered Fukushima water could be diluted with seawater and then safely released into the ocean without causing environmental problems.

But those assurances are of little comfort to many in the region, particularly Fukushima’s fishing industry which, like local farmers, has suffered from the outside perception that food from the region is unsafe.

Karyn Nishimura, At Fukushima plant, a million-ton headache: radioactive water, Japan Times, Oct. 7, 2019
 

Where to Go? 1 Million Tons Radioactive Water at Fukushima

In August 2019, Tepco projected that storage of radioactive water at the Fukushima nuclear plant would reach full capacity by around summer 2022 even after the expansion — the first time it has issued such a precise estimate.  According to Tepco, the Fukushima No. 1 plant had 960 massive tanks containing 1.15 million tons of treated water as of July 18, 2019. Water that has touched the highly radioactive melted fuel debris has been cleaned up through water treatment machines and is stored in the tanks, but the high-tech treatment machines are able to remove most radionuclides except tritium. The plant currently sees an increase of contaminated water by 170 tons a day, Tepco says.

Releasing tritium-tainted water into the sea in a controlled manner is common practice at nuclear power plants around the world, and it was generally considered the most viable option as it could be done quickly and would cost the least.  The head of the Nuclear Regulation Authority, Toyoshi Fuketa, has long said that releasing the treated water into the sea is the most reasonable option, but people in Fukushima, especially fishermen, fear it will damage the region’s reputation.

Addressing those concerns, the government panel, launched in November 2016, has been looking for the best option in terms of guarding against reputational damage. Injecting it into the ground, discharging it as steam or hydrogen, or solidification followed by underground burial have all been on the table. Under the current plan, Tepco is set to increase the tank space to store 1.37 million tons of water a total, but estimates show that will only last until summer 2022.  But the more space it creates, the bigger the decommissioning headache becomes.

Excerpts from KAZUAKI NAGAT, Fukushima nuclear plant to run out of tanks to store tritium-laced water in three years, Tepco says, Japan Times, Aug. 9, 2019
BY KAZUAKI NAGATA