Here is a good article written by Mari Yamaguchi that explains the state of contaminated water at the Fukushima Daiichi plant. Experts say that the ice wall that was built to keep groundwater from coming into the power plant and becoming contaminated with radioactivity is only half effective. A conventional drainage system also collects water from wells dug around the plant and pumps it out before it becomes contaminated. This water is stored in about 1,000 storage tanks near the facility. Read more about the construction, operation and maintenance costs that are coming out of the taxpayer’s pocket.
” NARAHA, FUKUSHIMA PREF. – A decision should be made sometime this year over whether to release into the sea water containing radioactive tritium from the crisis-hit Fukushima No. 1 nuclear plant, the chief of Japan’s nuclear regulator said Thursday, emphasizing it would pose no danger to human health.
“We will face a new challenge if a decision (about the release) is not made this year,” Nuclear Regulation Authority Chairman Toyoshi Fuketa told Naraha Mayor Yukiei Matsumoto, referring to the more than 1 million tons of coolant water and groundwater that has accumulated at the crippled facility. Naraha is located close to the Fukushima No.1 plant.
Fuketa said releasing the water into the sea after dilution is the only solution, saying “it is scientifically clear that there will be no impact on marine products or to the environment.”
Currently, Fukushima plant operator Tokyo Electric Power Company Holdings Inc. regularly filters contaminated coolant water and ground water from the damaged plant. The processed water is stored in hundreds of water tanks set up within the plant’s compound.
Dangerous radioactive materials are removed during filtration, but tritium — which is difficult to separate from water but relatively harmless to human health — remains.
“(Tepco) has been building new tanks, but it will eventually run out of land,” an NRA official later told The Japan Times.
With limited storage space for water tanks, observers warn that tritium could start leaking from the Fukushima plant.
The nuclear regulator’s chief underlined the need for the government and Tepco to make a decision quickly, saying, “It will take two or three years to prepare for the water’s release into the sea.”
At other nuclear power plants, water containing tritium is routinely dumped into the sea after it is diluted. The regulator has been calling for the release of the water after diluting it to a density lower than standards set by law.
According to the NRA, an average pressured-water reactor for commercial use in Japan usually dumps 60 trillion becquerels of tritium a year into the sea.
Local fishermen are, however, worried about the negative impact from the water discharge — in particular the effect of groundless rumors regarding the safety of marine life near the Fukushima plant. In the face of their opposition, Tepco has not yet reached a decision on how to deal with the stored water.
At the Fukushima plant contaminated water is building up partly because groundwater is seeping into the reactor buildings and mixing with water that has been made radioactive in the process of cooling the damaged reactors.
According to the NRA, there were 650 water tanks within the compound at the Fukushima No. 1 plant as of last month.
The density of tritium in the water ranges from 1 million to 5 million becquerels per liter. Legal restrictions require a nuclear power plant to dump tritium-tainted water after diluting it to 60,000 becquerels per liter, according to the NRA.
On March 11, 2011, tsunami inundated the six-reactor plant, which is located on ground 10 meters above sea level, and flooded its power supply facilities.
Reactor cooling systems were crippled and the Nos. 1 to 3 reactors suffered fuel meltdowns in the world’s worst nuclear catastrophe since the 1986 Chernobyl disaster. ”
by Kyodo, The Japan Times
” ONAHAMA, FUKUSHIMA PREF. – More than six years after a tsunami overwhelmed the Fukushima No. 1 nuclear power plant, Japan has yet to reach consensus on what to do with a million tons of radioactive water, stored on site in around 900 large and densely packed tanks that could spill should another major earthquake or tsunami strike.
The stalemate is rooted in a fundamental conflict between science and human nature.
Experts advising the government have urged a gradual release to the Pacific Ocean. Treatment has removed all the radioactive elements except tritium, which they say is safe in small amounts. Conversely, if the tanks break, their contents could slosh out in an uncontrolled way.
Local fishermen are balking. The water, no matter how clean, has a dirty image for consumers, they say. Despite repeated tests showing most types of fish caught off Fukushima are safe to eat, diners remain hesitant. The fishermen fear any release would sound the death knell for their nascent and still fragile recovery.
“People would shun Fukushima fish again as soon as the water is released,” said Fumio Haga, a drag-net fisherman from Iwaki, a city about 50 kilometers (30 miles) down the coast from the nuclear plant.
And so the tanks remain.
Fall is high season for saury and flounder, among Fukushima’s signature fish. It was once a busy time of year when coastal fishermen were out every morning.
Then came March 11, 2011. A magnitude 9 offshore earthquake triggered a tsunami that killed more than 18,000 people along the coast. The quake and massive flooding knocked out power for the cooling systems at the Fukushima nuclear plant. Three of the six reactors had partial meltdowns. Radiation spewed into the air, and highly contaminated water ran into the Pacific.
Today, only about half of the region’s 1,000 fishermen go out, and just twice a week because of reduced demand. They participate in a fish testing program.
Lab technicians mince fish samples at Onahama port in Iwaki, pack them in a cup for inspection and record details such as who caught the fish and where. Packaged fish sold at supermarkets carry official “safe” stickers.
Only three kinds of fish passed the test when the experiment began in mid-2012, 15 months after the tsunami. Over time, that number has increased to about 100.
The fish meet what is believed to be the world’s most stringent requirement: less than half the radioactive cesium level allowed under Japan’s national standard and one-twelfth of the U.S. or EU limit, said Yoshiharu Nemoto, a senior researcher at the Onahama testing station.
That message isn’t reaching consumers. A survey by the Consumer Affairs Agency in October found that nearly half of Japanese weren’t aware of the tests, and that consumers are more likely to focus on alarming information about possible health impacts in extreme cases, rather than facts about radiation and safety standards.
Fewer Japanese consumers shun fish and other foods from Fukushima than before, but 1 in 5 still do, according to the survey. The coastal catch of 2,000 tons last year was 8 percent of pre-disaster levels. The deep-sea catch was half of what it used to be, though scientists say there is no contamination risk that far out.
Naoya Sekiya, a University of Tokyo expert on disaster information and social psychology, said that the water from the nuclear plant shouldn’t be released until people are well-informed about the basic facts and psychologically ready.
“A release only based on scientific safety, without addressing the public’s concerns, cannot be tolerated in a democratic society,” he said. “A release when people are unprepared would only make things worse.”
He and consumer advocacy group representative Kikuko Tatsumi sit on a government expert panel that has been wrestling with the social impact of a release and what to do with the water for more than a year, with no sign of resolution.
Tatsumi said the stalemate may be further fueling public misconception: Many people believe the water is stored because it’s not safe to release, and they think Fukushima fish is not available because it’s not safe to eat.
The amount of radioactive water at Fukushima is still growing, by 150 tons a day.
The reactors are damaged beyond repair, but cooling water must be constantly pumped in to keep them from overheating. That water picks up radioactivity before leaking out of the damaged containment chambers and collecting in the basements.
There, the volume of contaminated water grows, because it mixes with groundwater that has seeped in through cracks in the reactor buildings. After treatment, 210 tons is reused as cooling water, and the remaining 150 tons is sent to tank storage. During heavy rains, the groundwater inflow increases significantly, adding to the volume.
The water is a costly headache for Tokyo Electric Power Company Holdings Inc., the utility that owns the plant. To reduce the flow, it has dug dozens of wells to pump out groundwater before it reaches the reactor buildings and built an underground “ice wall” of questionable effectiveness by partially freezing the ground around the reactors.
Another government panel recommended last year that the utility, known as Tepco, dilute the water up to about 50 times and release about 400 tons daily to the sea — a process that would take almost a decade to complete. Experts note that the release of tritiated water is allowed at other nuclear plants.
Tritiated water from the 1979 Three Mile Island accident in the United States was evaporated, but the amount was much smaller, and still required 10 years of preparation and three more years to complete.
A new chairman at Tepco, Takashi Kawamura, caused an uproar in the fishing community in April when he expressed support for moving ahead with the release of the water.
The company quickly backpedaled, and now says it has no plans for an immediate release and can keep storing water through 2020. Tepco says the decision should be made by the government, because the public doesn’t trust the utility.
“Our recovery effort up until now would immediately collapse to zero if the water is released,” Iwaki abalone farmer Yuichi Manome said.
Some experts have proposed moving the tanks to an intermediate storage area, or delaying the release until at least 2023, when half the tritium that was present at the time of the disaster will have disappeared naturally. ”
by Mari Yamaguchi, The Japan Times
” A construction project to create frozen soil walls that encircle the ground beneath Tokyo Electric Power Company Holdings Inc.’s disaster-hit Fukushima No. 1 nuclear power plant is nearly finished.
Although TEPCO insists that the inflow of groundwater beneath the reactor buildings has been reduced, some members of the Nuclear Regulation Authority are skeptical about the project’s effectiveness. With ¥34.5 billion of public funds being spent on this project, the centerpeice of countermeasures for contaminated water, its cost-effectiveness is being carefully watched.
The project entails building a 1.5-kilometer-long frozen soil wall encircling the Nos. 1 to 4 reactors, with 1,568 pipes buried to a depth of about 30 meters below ground and coolant running through the pipes at minus 30 C to chill the soil.
The process is expected to prevent groundwater from flowing into the contaminated, highly radioactive underground water at such sites as the reactor buildings, and to avoid an increase of contaminated water.
The project began in March last year, and operations to freeze the final section, about seven meters wide, on the mountain side began in August this year.
The temperature of the underground soil has remained below zero, except for a part close the surface that is affected by outdoor air, meaning the project to create the 30-meter-deep walls is almost complete.
According to TEPCO’s assessment, before the project started, about 400 tons of groundwater was flowing into the ground underneath the reactor buildings and other sites daily.
TEPCO had initially calculated that the daily inflow of groundwater could decrease to dozens of tons once the walls were installed. However, between April and September the inflow per day was between 120 tons and 140 tons, and in October it was around 100 tons. That the amount of inflow has decreased in stages as the soil freezing progressed seems to prove that the project has been effective to a certain extent. However, it is unclear if the inflow will decrease further in the future.
In parallel with the frozen soil wall project, TEPCO dug about 40 subdrain wells to pump up groundwater before it flows into the reactor buildings. It also reinforced measures to prevent rainwater from soaking into the ground by paving 1.33 million square meters of surface.
In the NRA view, those measures must also contribute greatly to reducing the inflow, casting doubt on the frozen soil walls project by saying the effect of them alone may be limited. The agency has become distrustful of TEPCO and urged the company to verify the effects.
Hiroshi Miyano, visiting professor at Hosei University specializing in system safety, said: “There is sure to be a part that doesn’t freeze completely, and it’s impossible to reduce the inflow to zero. TEPCO must continue applying this measure in tandem with draining the nearby wells for a while.” ”
by The Yomiuri Shimbun
” Radioactive material from the Fukushima Dai-ichi nuclear power plant disaster is accumulating in the sands and brackish groundwater beneath beaches up to 60 miles away from the nuclear power plant itself, according to a new study published in the Proceedings of the National Academy of Sciences on October 2. The study is the first to identify accumulations of radioactive cesium in this previously unsuspected place.
“No one is either exposed to, or drinks, these waters, and thus public health is not of primary concern here,” the researchers noted in the new study, but “this new and unanticipated pathway for the storage and release of radionuclides to the ocean should be taken into account in the management of coastal areas where nuclear power plants are situated.”
The theory proposed in the new study is that high levels of radioactive cesium-137 were transported along the coast following the 2011 nuclear disaster, and subsequently got “stuck” to surfaces of grains of sand, rather than being nearly immediately dispersed and diluted as was “expected.”
“No one expected that the highest levels of cesium in ocean water today would be found not in the harbor of the Fukushima Dai-ichi nuclear power plant, but in the groundwater many miles away below the beach sands,” stated researcher Virginie Sanial of Woods Hole Oceanographic Institution.
That may well be true, but it’s also true that there people who acknowledge that accurately modeling systems as complex as those found in the natural world is essentially impossible — and who would argue that the precautionary principle should be kept in mind when dealing with something as dangerous as nuclear power. After all, predictions relating to outcomes are only ever going to be of related accuracy.
The press release provides more: “Cesium-enriched sand resided on the beaches and in the brackish, slightly salty mixture of fresh water and salt water beneath the beaches. But in salt water, cesium no longer ‘sticks’ to the sand. So when more recent waves and tides brought in salty seawater from the ocean, the brackish water underneath the beaches became salty enough to release the cesium from the sand, and it was carried back into the ocean.
“The scientists estimated that the amount of contaminated water flowing into the ocean from this brackish groundwater source below the sandy beaches is as large as the input from two other known sources: ongoing releases and runoff from the nuclear power plant site itself, and outflow from rivers that continue to carry cesium from the fallout on land in 2011 to the ocean on river-borne particles. All three of these ongoing sources are thousands of times smaller today compared with the days immediately after the disaster in 2011.
“The team sampled eight beaches within 60 miles of the crippled Fukushima Dai-ichi Nuclear Power Plant between 2013 and 2016. They plunged 3- to 7-foot-long tubes into the sand, pumped up underlying groundwater, and analyzed its cesium-137 content. The cesium levels in the groundwater were up to 10 times higher than the levels found in seawater within the harbor of the nuclear power plant itself. In addition, the total amount of cesium retained more than 3 feet deep in the sands is higher than what is found in sediments on the seafloor offshore of the beaches.”
So, what the new research does in essence is provide yet another example of the way that nuclear disasters and nuclear contamination can impact the natural environment in ways that aren’t immediately expected or intuitive to most. ”
by James Ayre
source with internal links
” The discovery of falsely configured monitoring equipment at the stricken Fukushima No. 1 nuclear power plant means the groundwater flowing underneath it might have gotten contaminated from April onward, Tokyo Electric said Friday.
The utility said incorrect gauge settings were used to measure groundwater levels in six of the wells near reactors 1 and 4. This resulted in groundwater readings about 70 cm higher than reality, which means the beleaguered power utility has been mismanaging the groundwater there for months.
To prevent tainted water from leaking from the plant, Tokyo Electric Power Company Holdings Inc. installed water gauges so it could keep the groundwater levels in the wells a meter higher than the contaminated water in the buildings.
Tepco adjusts the amount of water in wells called subdrains around the buildings to keep the groundwater higher than the tainted water inside them, which prevents it from flowing out. If the groundwater levels sink below the level of the radioactive water, it might leak out.
On Friday, Tepco said the estimated groundwater level in one of the six subdrain wells close to reactor 1 fell below the level in the reactor building at least eight times during the five-day period to May 21 because the gauges were set incorrectly.
Groundwater levels were 2 mm to 19 mm lower than the level in the buildings, Tepco said, adding that it does not know precisely how long each of these problematic situations lasted because water level data is collected by the hour.
Tepco said groundwater levels in five other wells affected by the incorrect settings did not fall below the levels in the nearby reactor buildings.
All six are in the area surrounded by an underground ice wall designed to prevent groundwater leakage.
According to Tepco, the incorrect settings date as far back as April 19. The earliest error affected the gauge in a well where groundwater fell to hazardous levels.
In the world’s worst nuclear disaster since Chernobyl, reactors 1, 2 and 3 at the plant experienced core meltdowns and reactors 1, 3 and 4 were severely damaged by hydrogen explosions following a massive offshore earthquake that spawned large tsunami in March 2011. ”
by Jiji, Kyodo via The Japan Times