Water, Soil And Radiation: Why Fukushima Will Take Decades To Clean Up | KUOW News and Information

Water, Soil And Radiation: Why Fukushima Will Take Decades To Clean Up

Mar 10, 2016
Originally published on March 11, 2016 4:38 pm

Five years after an earthquake and tsunami caused a series of meltdowns at the Fukushima Dai-ichi nuclear plant in Japan, there are signs of progress. Many workers cleaning up the ruined plant no longer need to suit up in full respirators. Some nearby villages that were evacuated are open to residents.

But there are still plenty of problems.

"Fukushima Dai-ichi is a complicated cleanup site," says Dale Klein, a former chairman of the U.S Nuclear Regulatory Commission who now consults for the Tokyo Electric Power Company, or Tepco, which owns the plant.

Perhaps the biggest problem is water, Klein says. Groundwater from nearby mountains constantly seeps through the ruined building before spilling into the ocean. Tepco has tried a number of different approaches (including a massive underground ice wall) to try to slow the incursion, but so far efforts to stop it have been only partially successful.

Instead, the company must send the groundwater through a complex filtration system that removes radioactivity. The system is effective at removing some of the most dangerous elements, but one isotope of hydrogen, called tritium, can't be removed because it's literally embedded in the H2O of the water molecules.

"Tritium is part of the water itself, so how do you filter water out of water?" Klein says.

The best solution might be to dilute the radioactive groundwater and then release it into the ocean. But fishermen and the public would have to be convinced. For now, nearly a million tons of water is being stored all over the site.

"There are about a thousand containers, steel containers that hold this water," he says.

The land around the plant was also contaminated by the accident. Azby Brown is with the nonprofit organization Safecast, which independently monitors radiation levels in Fukushima prefecture. He says readings by Safecast and the government show that radiation levels in the region around the plant have fallen by roughly half.

"There's no question that the radiation levels have decreased compared to 2011," he says.

Some of that drop is due to the natural radioactive decay, but there has also been a huge cleanup effort. Workers across Fukushima have been scraping up contaminated topsoil and storing it in bags. And that's created its own problem, Brown says.

"There are now about 9 million bags of decontamination waste from all over the prefecture that are being consolidated into these vast fields with these pyramids of radioactive waste," he says.

Just like with the water, regulators aren't quite sure what to do with all that soil. Japan doesn't have a centralized radioactive waste dump to take it to.

In the longer term, the biggest issue will be what to do with the highly radioactive cores of the reactors themselves, each filled with melted uranium fuel. After the Chernobyl nuclear accident in Ukraine, Soviet officials opted to pour concrete over the melted reactor core. But Tepco's chief nuclear officer, Takafumi Anegawa, says Fukushima's fuel has got to be removed because the plant's presence on the coast poses a threat to the environment. "This condition cannot continue for many years," he says.

Tepco doesn't really have any firm ideas about how to get the melted fuel out. "So far, there's no specific clear solution," Anegawa says.

In fact, the company hasn't even been able to look inside to see what needs to be done. Anegawa says the radiation is so intense that it's fried the circuits of several robots sent in to investigate.

Dale Klein, the safety consultant, thinks that eventually robots will be used to cut up the molten cores of the reactors and seal them inside concrete containers. But he says it's not going to happen overnight.

"This will be a several-decades process of cleanup," he says.

In other words, the Fukushima accident will be with the people of Japan for generations to come.

Copyright 2017 NPR. To see more, visit http://www.npr.org/.

KELLY MCEVERS, HOST:

Tomorrow marks five years since Japan was hit by a powerful earthquake and tsunami. The wall of water struck many points along the coast, including the Fukushima Dai-ichi nuclear power plant where three nuclear reactors melted down. NPR's Geoff Brumfiel reports that some progress has been made in cleaning up the site since then, but there's still a lot of work left.

GEOFF BRUMFIEL, BYLINE: When the crisis began at Fukushima Dai-ichi, hundreds of thousands of people fled. Radioactivity spread across rice paddies and towns. Five years later, the cleanup is well underway, and some villages are again open to residents. But there's still lots and lots of problems, and Dale Klein, a former chairman of the U.S. Nuclear Regulatory Commission, says one really stands out.

DALE KLEIN: I think what makes Fukushima Dai-ichi the most challenging is water.

BRUMFIEL: Klein now consults for the Tokyo Electric Power Company or TEPCO which owns the plant. The water he's talking about comes from the mountains surrounding the reactors. It's groundwater that constantly seeps through the ruined buildings before spilling into the ocean. Efforts to stop it have only been partially successful. TEPCO has gotten good at filtering radioactivity out of this water, but one isotope of hydrogen called tritium cannot be removed because it's literally embedded in the H2O of the water molecules.

KLEIN: Tritium is a part of the water itself, and so how do you filter water out of water?

BRUMFIEL: The best solution might be to dilute the radioactive water and then release it into the ocean. But fishermen and the public would have to be convinced. For now, it's being stored on-site.

KLEIN: There are about 1,000 containers - steel containers that hold this water.

BRUMFIEL: The land around the plant was also contaminated by the accident. Azby Brown is with the nonprofit Safecast organization which independently monitors radiation levels in Fukushima prefecture. He spoke via Skype from Tokyo.

AZBY BROWN: There's no question that the radiation levels have decreased compared to 2011.

BRUMFIEL: A recent government survey showed that levels are down by more than half since the accident. Some of that drop is due to the natural radioactive decay, but there's also been a huge cleanup effort. Workers across Fukushima have been scraping up contaminated topsoil and storing it in bags. And that's created its own problem, Brown says.

BROWN: There are now about 9 million bags of decontamination waste from all over the prefecture that are being consolidated into these vast fields with these sort of pyramids of, you know, radioactive waste.

BRUMFIEL: Just like the water, regulators aren't quite sure what to do with all that soil. But the biggest issue long-term is how to deal with the highly radioactive cores of the reactors themselves, each filled with melted uranium fuel. Takafumi Anegawa, TEPCO's chief nuclear officer, says it's got to be removed.

TAKAFUMI ANEGAWA: This condition cannot continue for many years.

BRUMFIEL: But Anegawa also says TEPCO doesn't really have a clue how to get the melted fuel out.

ANEGAWA: So far, there's no specific, clear solution.

BRUMFIEL: In fact, the company hasn't even been able to look inside to see what needs to be done. The radiation is so intense, Anegawa says, it's fried the circuits of several robots sent in to investigate. Dale Klein, the safety consultant, thinks that eventually, robots will be used to cut up the molten cores of the reactors and seal them inside concrete containers. But he says it's not going to happen overnight

KLEIN: This will be a several-decades process of cleanup. It will be much more complicated than a 3-mile island. In a 3-mile island, it took 14 years to clean up.

BRUMFIEL: In other words, the Fukushima accident will be with the people of Japan for generations to come. Geoff Brumfiel, NPR News. Transcript provided by NPR, Copyright NPR.