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” Tons of contaminated water posing huge hurdles to cleanup …
A lot of ink was consumed by media after the Fukushima Daiichi Nuclear Power Station disaster in March 2011, and then everything got quiet. With most of the media silent about the cleanup, the public may think the worst is over and the operating company TEPCO (Tokyo Electric Power Co.) is cleaning up the site.
Nothing could be further from the truth.
Once the remediation efforts began on the irradiated plant site, it quickly became clear the contaminated water being stored at Fukushima was going to be the largest component to the mediation efforts.
Water from the devastated reactor cooling system was leaking out into the ocean, allowing it to spread into the immediate vicinity and around the world through ocean currents. Added to this, rainwater runoff coming from the surrounding mountains flowed through the devastated site, picking up radioactive material on its way to the ocean.
The influx of contaminated water prompted grave concerns over the impact on sea life in the area and around the world.
Water, water everywhere
The first response to combat the water contamination problem was to reject remediation proposals given by experts, such as building a concrete wall 60 feet into the ground to stop the estimated 76,000 gallons of groundwater from leaking into the ocean. Instead, TEPCO hurriedly constructed plastic- and clay-lined underground water storage pits that soon developed leaks.
When that plan didn’t work, their next step was to build above-ground storage tanks – a lot of them – to store the cooling water and some of the groundwater runoff. At the time, there was no good, efficient way to clean the water, so TEPCO just kept building more tanks to try to stay ahead of the problem.
As the tank farm grew, it was discovered that more than 300 tons of radioactive water had leaked out of a storage tank onto the site. The 2,400 gallons of water per day leaking into the ocean was heavily contaminated with strontium-90 and cesium-137. With so many tanks on the site, more leaks were anticipated.
To solve the problem, plant and government officials then decided to build an “ice wall” around the reactor site to halt the flow of water. The plan was to construct a $300 million mile-long subterranean ice wall around the complex to collect the runoff, funnel it into trenches, freeze it and then transport it to safe disposal sites elsewhere.
The technology was not new. Ice walls have used in the mining industry for years, but it’s the first time it was constructed and deployed in radioactive conditions by workers in bulky and cumbersome radiation suits. Work commenced on the ice wall in June amid much skepticism in the scientific community.
Part of the work was the effort to create an “ice plug” in a tunnel to stop water from flowing into the Number 2 reactor building and becoming contaminated. Stopping the flow of water would have allowed clean-up personnel to pump the water out of the reactor and treat it.
Engineers from TEPCO have injected more than 400 tons of ice and dry ice (frozen carbon dioxide) into the tunnel in an effort to freeze a section of the passage solid.
In August, just 10 weeks after work began on the plug, TEPCO conceded defeat and announced the efforts to construct the plug failed.
TEPCO did completely fill one section of the trench to Reactor 2 (Turbine Building) Nov. 6 and began pumping water out of the trench Nov. 7.
After six hours of pumping, site operators only managed to reduce the water level in the trench by eight inches, and the water returned to its original level in just two-and-a-half hours after pumping operations ceased.
Company officials announced they would experiment with cement and other sealants to stem the water, rather than use ice.
Officials at Japan’s NRC (Nuclear Regulation Authority) raised doubts at the time that the proposal would be any more effective than the ice plug.
In a prepared statement, TEPCO officials stated, “The difficulties encountered in freezing the contaminated water does not in any way represent a ‘setback’ in development of the ice wall, for which construction is proceeding as planned.”
As if things couldn’t get worse, less than two months ago, TEPCO once again came out with an announcement that it was having problems with the ice wall after all.
In a Sept. 22 press conference, TEPCO officials said the NRC was going to cease operations on the ice wall and pour cement into the wall instead. Their hope is that it will be enough to retain the contaminated water on the site.
But to follow that line of reasoning, for every cubic foot of concrete put into the trench, a cubic foot of contaminated water is displaced and could go into the ocean. TEPCO has stated that none of the displaced water will make it to the ocean, because workers will pump out the water as they fill with cement.
However, because the ice wall trenches and the plant buildings are connected, the entire volume of water in these two areas would have to be pumped out to fill the trenches with cement. Industry experts are unclear as to whether or not TEPCO has enough water storage tanks to hold the additional volume of water.
While the NRC had decided to stop work on the ice wall, TEPCO President Naomi Hirose stated officials “will never give up”” on the wall. This seems to put the NRC and TEPCO on a collision course.
TEPCO said the plan was to leave the ice already in the tunnel in place and fill the rest of the trench with concrete. The NRC responded that concrete gives off heat as it dries and it would melt the ice.
TEPCO said it would take that statement under advisement.
The clock is ticking on the containment problem. According to TEPCO, radiation levels in groundwater sampled from several monitoring wells have been very slowly rising since last summer, and radioactive strontium has been detected since October.
The second debate
While the debate continues over how to stop water from leaking into the ocean, another debate is raging over how to clean up the water already contained. It is estimated that the site is filling one 27- foot tall water storage tank every other day.
More than 780 suggestions from around the world have been sent into Japan’s International Research Institute for Nuclear Decommissioning in the past year in response to its call for solutions to the contaminated water problem. It seemed as that the most promising technology to solve the problem has an unlikely name: ALPS.
Toshiba Corp’s Advanced Liquid Processing System (ALPS) is a water remediation technology that uses apatite. It’s a mineral similar to bone in its makeup and has the ability to capture and hold certain elements in its microstructure, including strontium.
The ALPS system was a proven technology and had worked well in other applications, making it an extremely attractive technology.
One of the ALPS success stories was at the Department of Energy Hanford site in southeastern Washington state. It was at Hanford that the U.S. government produced more than 20 million pieces of uranium metal fuel for nine nuclear reactors as well as five decades of nuclear weapons production. Five fabrication plants in the center of the site discharged an estimated 450 billion gallons of liquids into soil disposal sites and 53 million gallons of radioactive waste to 177 large underground tanks.
Production at the site ended in the late 1980s, and the cleanup began shortly thereafter.
At the Hanford site, apatite is used to block strontium from liquid nuclear waste in soil from flowing into the adjacent Columbia River.
At the time it was considered, there were concerns, however, that the technology may not work at Fukushima because it had never been tried in a salt-water environment.
According to Tatsuya Shinkawa, director of the Japanese government’s Nuclear Accident Response Office, the technology has captured 90 percent of the strontium in the ground water at the Hanford site.
“But that site is far from the sea, and this method hasn’t been used in an environment so close to the ocean,” he said.
With over 350 tons of highly contaminated water waiting to be treated, ALPS seemed to run into problems before it even was put to the test.
The first obstacle came in September 2012 when the NRA demanded additional safety tests of the vessels that would store the radioactive waste filtered out of the water.
When the system was finally put on line in March 2013, it was plagued with problems with leaks from tanks and vessels that seemed to be derived from poor welding. These and other problems limited the system to only trial runs.
Then in November, a meeting was held of a “task force for a high performance multi-nuclide removal system” (aka ALPS) that was sponsored by TEPCO. After going through the meeting notes, available only in Japanese, the site tests for the ALPS system apparently didn’t go well. ALPS generates too much waste material, or “slurry,” that is still radioactive and would have to be stored.
The report also goes on to state that the wrong type of filtering material is inside the ALPS equipment. The radioactive material in the water was thought to exist as “ions,” individual molecules having a static charge. It seems that the radioactive molecules in the water actually exist as “colloids” or clumps of material. Colloidal material is much bigger than ions and would quickly plug filler material designed to separate individual molecules.
Why the nature of the radioactive material was not discovered before testing remains to be explained.
In the meantime, while false starts and outright failures continue to plague the Fukushima cleanup efforts, the effects of the disaster are still being felt.
In April, researchers at Oregon State University reported the radiation levels in some albacore tuna caught off the coast of the Pacific Northwest have tripled since the nuclear plant disaster. Earlier, in November 2013, the National Oceanic and Atmospheric Administration, or NOAA, announced over 1 million tons of radioactive debris from the Fukushima site were floating 1,700 miles off the U.S. coastline, between Hawaii and California.
New research is also showing that the radiation from the Fukushima site is having an adverse effect on wildlife. Timothy Mousseau, professor of biological sciences at the University of South Carolina and researcher for the Chernobyl and Fukushima Research Initiative, presented findings of a study to the International Ornithological Congress in Tokyo last August that suggests radiation contamination around Fukushima Daiichi, even at low levels, is negatively impacting biodiversity and wildlife populations.
Mousseau and his team did a four-year study on the effects of radiation on birds in Fukushima which revealed information contradicting volume I of the United Nations Scientific Committee on the Effects of Atomic Radiation’s report, “Levels and effects of radiation exposure due to the nuclear accident after the 2011 great east-Japan earthquake and tsunami.”
“Contrary to governmental reports, there is now an abundance of information demonstrating consequences (i.e. injury) to individuals, populations, species, and ecosystem function stemming from the low dose radiation due to the Chernobyl and Fukushima disasters,” Mousseau said.
With evidence mounting that the effects of Fukushima are far worse that official government reports, officials can only hope that an effective way will be found to clean up the nuclear plant and the surrounding area.
WND has reported multiple times on the Fukushima disaster, including when there was more bad news for the operators, when a super-cool plan to help the cleanup was developed and when officials declared the problems “under control.”