NRA: Ice wall effects ‘limited’ at Fukushima nuclear plant — The Asahi Shimbun

” Citing “limited, if any effects,” the Nuclear Regulation Authority said a highly touted “frozen soil wall” should be relegated to a secondary role in reducing contaminated groundwater at the Fukushima No. 1 nuclear plant.

The government spent 34.5 billion yen ($292 million) to build the underground ice wall to prevent groundwater from mixing with radioactive water in four reactor buildings at the crippled plant.

But the NRA, Japan’s nuclear watchdog, concluded on Dec. 26 that the wall has been ineffective in diverting the water away from the buildings. It said that despite the low rainfall over the past several months, the amount of groundwater pumped up through wells outside the frozen wall on the seaside is still well above the reduction target.

It urged the plant operator, Tokyo Electric Power Co., to tackle the groundwater problem primarily with pumps, not the ice wall.

In response, TEPCO at the meeting said that by next autumn, it will double its capacity to pump up groundwater from the current 800 tons a day.

About 400 tons of groundwater enters the damaged reactor buildings each day and mixes with highly radioactive water used to cool melted nuclear fuel.

The ice wall project, compiled by the industry ministry in May 2013, was seen as a fundamental solution to this problem that has hampered TEPCO’s cleanup efforts since the triple meltdown in March 2011.

Some 1,568 frozen ducts were inserted 30 meters deep into the ground to circulate a liquid at 30 degrees below zero. The freezing process was supposed to have created a solid wall of ice that could block the groundwater.

TEPCO began freezing the wall on the seaside in March. It announced in the middle of October that the temperature at all measuring points in that area was below zero.

Before the frozen wall project, TEPCO had to pump up about 300 tons of contaminated water a day. The daily volume dropped to about 130 tons in recent weeks, but it was still well beyond the target of 70 tons.

Still, TEPCO boasted about the effectiveness of the ice wall at the meeting with the NRA on Dec. 26, saying, “We are seeing certain results.”

The NRA, however, said the results are limited at best.

Toyoshi Fuketa, an NRA commissioner, already warned TEPCO in October that it cannot expect the ice wall to be highly effective in containing the groundwater.

“Pumping up groundwater through wells should be the main player because it can reliably control the groundwater level,” Fuketa said at that time. “The ice wall will play a supporting role.”

That sentiment was echoed at the Dec. 26 meeting.

However, the NRA approved the utility’s plan to begin freezing dirt for a wall on the mountain side of the nuclear plant.

The NRA was previously concerned about risks posed by the new ice wall. If it totally blocked groundwater from the mountain side, the water level within the frozen soil near the reactors could become too low, allowing highly contaminated water inside the reactor buildings to flow out more rapidly.

The NRA urged TEPCO to delay work on the mountain side until the ice wall on the seaside portion proved effective.

But it reversed its stance, saying a sharp drop in the groundwater level is unlikely based on the ineffectiveness of the existing ice wall.

“The frozen wall on the mountain side will not be able to block groundwater because the wall on the seaside was also unable to do so,” Fuketa said. “It will not be very dangerous to freeze the wall on the mountain side as long as the work is carried out carefully.”

TEPCO will start the work to freeze the ducts at five sections as early as next year.

Masashi Kamon, professor emeritus of geotechniques at Kyoto University, expressed skepticism about continuing the ice wall project without a full scrutiny of the underground conditions.

“Soil around the tunnels for underground pipes must be hard to freeze,” he said. “TEPCO should find out the conditions of the very bottom of the ice wall by drilling at least one section. It is questionable to continue with the project without a review.” ”

by Kohei Tomida

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Accelerate water-purifying work at Fukushima plant to cut leakage risk — The Yomiuri Shimbun

” The volume of contaminated water continues to increase at Tokyo Electric Power Company Holdings Inc.’s Fukushima No. 1 nuclear power plant. Efforts to deal with this problem must be reinforced.

TEPCO has compiled a new set of measures to deal with the radioactive water. The steps are aimed at reducing to nearly zero the contaminated water inside reactor buildings, the prime source of the tainted water.

Under the new measures, the contaminated water accumulated in the basements of reactor buildings is to be purified and then transferred to storage tanks. At the same time, facilities exclusively used for purifying the tainted water are to be doubled, and the existing storage tanks will be replaced with larger ones, increasing the overall storage capacity.

Meanwhile, the volume of groundwater to be pumped up from the wells near the reactor buildings is to be increased. This is aimed at reducing the flow of underground water into the buildings, thus preventing a vicious cycle of generating more tainted water.

If all goes well, the increase in the volume of contaminated water is expected to nearly stop by 2020. We hope TEPCO will realize this goal steadily.

The measures taken so far have centered on the construction of “ice walls,” to prevent groundwater from entering the reactor buildings by freezing the underground soil around the buildings. Because this step has failed to prove effective even more than half a year after the related facilities were put into operation, TEPCO decided to shift its priority measures.

The new measures will require the approval of the Nuclear Regulation Authority. Both TEPCO and the NRA must cooperate closely so that the necessary work will not be delayed.

Consider ocean release

The reactor buildings have, in effect, turned into storage facilities for contaminated water. The volume of tainted water totals about 68,000 tons. Although the amount of radioactive material contained in the water has declined markedly when compared to the amount immediately after the nuclear accident occurred, it still remains at a high level.

The large amount of contaminated water inside the reactor buildings carries a risk of radiation exposure, posing a serious impediment to the work to decommission the plant. If highly radioactive water starts leaking underground out of the buildings and into the sea, it will create a serious situation.

Even if new measures proceed smoothly, however, tasks remain. The volume of purified water to be stored in the tanks is expected to nearly double by 2020 to about 1.2 million tons. Not only will this entail a huge maintenance cost, but there is also a danger that the water will leak if the tanks are damaged by an earthquake or other factors.

Releasing purified water that has met the existing safety criteria into the sea must be seriously considered. The discharge of purified water into the ocean has been routinely conducted at nuclear power-related facilities both at home and abroad.

It is important for both the government and TEPCO to do their utmost to explain such a plan in detail in order to win the understanding of local residents concerned. Efforts should also be made to take measures to prevent groundless rumors from adversely affecting the fisheries industry and other sectors.

It is also necessary to continuously ascertain the effect of the ice walls. Although nearly 100 percent of the walls have already been frozen, groundwater is reportedly flowing through thin gaps in the walls. Rainwater seeping through the topsoil has also increased the amount of groundwater inside the buildings.

TEPCO is proceeding with work to fill the gaps in the ice walls. If the work proves effective, the goal of reducing to zero the increase in the contaminated water will be realized two years earlier than envisaged. We hope TEPCO will strenuously work to block the flow of groundwater into the buildings. ”

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Tepco admits success of Fukushima ice wall still unknown — The Japan Times

” Tokyo Electric Power Holdings Inc. and the government bet big on an underground ice wall as a key measure to battle the tainted water issue at the crippled Fukushima No. 1 nuclear plant.

But whether the ¥35 billion gambit funded by the government is working to block the inflow of groundwater remains unclear even six months after the utility started freezing an area of underground soil.

Tepco said it needs more time to judge whether the system is working. But the Nuclear Regulation Authority, Japan’s nuclear watchdog, appears skeptical on the effectiveness of the 1.5-km-long wall that encircles reactor buildings 1 to 4, asking Tepco to deal with the issue but without counting on it.

So far Tepco has finished freezing the east side of the ice wall — albeit with delays caused by severe typhoon-driven rains — and 95 percent of the west side but has yet to get the NRA’s approval to freeze the rest of it.

“It’s really unfortunate and I am very sorry” for not being able to provide an assessment of the ice wall, Naohiro Masuda, who heads Tepco’s decommissioning project, told a news conference Thursday.

Masuda said in August that Tepco would be able to provide an assessment of the effectiveness of the ice wall in September, and that the utility would have finished freezing the east side by then.

But Masuda said unexpected heavy rain during recent typhoons melted some parts of the structure.

Masuda said workers have since repaired the damage and finished freezing the east side 100 percent. But he declined to say when the assessment will be released.

The purpose of the ice wall is to block groundwater before it can enter the reactor buildings, which are located between nearby mountains and the ocean.

To do this, Tepco pumps groundwater that has flowed west to east toward five wells near the ocean, back into the reactors to cool them.

If the wall succeeds, the water being pumped from the ocean wells should reduce to about 70 tons each day, from hundreds of tons, according to Tepco. The daily level was between 600-1,200 tons in September, which Tepco attributed to heavy rains.

About 180 tons of groundwater a day seeps into the reactor buildings through cracks or holes and is mixed with contaminated water inside, causing the amount of tainted water at the plant to increase daily.

Currently, about 68,000 tons of tainted water is stored there but the risk remains that it could leak if another powerful quake hits near the facility.

For Tepco, the success of the ice wall is fundamental to achieve its next major goal of removing the contaminated water flooding the basement floors of the reactor buildings.

The utility plans to remove the water by 2020, but believes it can speed up the process by two years if the underground wall works.

The NRA, however, remains unconvinced.

“(Tepco) needs to come up with measures that do not rely on the ice wall and complete the removal of the tainted water from the building by 2020,” Toyoshi Fuketa, deputy NRA chairman, told Tepco officials at a panel meeting Wednesday.

During the meeting, Tepco expressed its intention to freeze the entire west side of the wall.

But Fuketa said, “That’s out of discussion,” since it was still unclear whether the east side was effectively blocking groundwater.

Among the NRA’s concerns is that completely blocking the groundwater on the west side might reduce the groundwater level below the tainted flooded water line in the reactor buildings, which would allow tainted water to leak out.

But as the wall appears to have done little to reduce the amount of groundwater pumped daily, the NRA ordered Tepco to come up with alternative measures.

The NRA has suggested that Tepco strengthen the pumping capability of wells around the reactor buildings to collect the groundwater before it can seep inside.

Tepco said at the Wednesday meeting that it will still be able to finish the removal of tainted water in the buildings by 2020 without the ice wall. ”

by Kazuaki Nagata

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Tepco to begin removing tainted water at Fukushima plant — The Asahi Shimbun

” Tokyo Electric Power Co. intends to begin pumping up highly contaminated water accumulating in the basements of buildings at its wrecked Fukushima No. 1 nuclear power plant by the end of March.

TEPCO disclosed its strategy Sept. 28 at a review meeting with the Nuclear Regulation Authority, the government’s nuclear watchdog.

In response, the NRA urged the utility to provide a detailed road map for the project.

Removing the huge volume of radioactive water in the reactor, turbine and other buildings has posed an urgent challenge for TEPCO.

The NRA pressed it to take action as soon as possible, pointing out that the contaminated water in the buildings’ basements is a likely reason flowing groundwater also gets polluted.

The NRA is also concerned that the contaminated water in the basements might leak into the sea if the nuclear complex is struck by another powerful tsunami.

TEPCO estimates that 68,000 tons of tainted water exists below the reactor and turbine buildings, as well as other structures.

Particularly worrisome is the estimated 2,000 tons of highly radioactive water in the condensers of the No. 1 through No. 3 turbine buildings, which accounts for 80 percent of the radioactive materials in all of the tainted water.

The contaminated water was transferred to the condensers in the immediate aftermath of the March 2011 triple meltdown.

TEPCO plans to finish transferring the water in the condensers by the first half of the next fiscal year and all of the contaminated water in the basements by 2020. ”

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Reassessing the 3.11 disaster and the future of nuclear power in Japan: An Interview with former Prime Minister Kan Naoto — The Asia-Pacific Journal

” Introduction

For more than two decades, the global nuclear industry has attempted to frame the debate on nuclear power within the context of climate change: nuclear power is better than any of the alternatives. So the argument went. Ambitious nuclear expansion plans in the United States and Japan, two of the largest existing markets, and the growth of nuclear power in China appeared to show—superficially at least—that the technology had a future. At least in terms of political rhetoric and media perception, it appeared to be a winning argument. Then came March 11, 2011. Those most determined to promote nuclear power even cited the Fukushima Daiichi accident as a reason for expanding nuclear power: impacts were low, no one died, radiation levels are not a risk. So claimed a handful of commentators in the international (particularly English-language) media.

However, from the start of the accident at Fukushima Daiichi on March 11 2011, the harsh reality of nuclear power was exposed to billions of people across the planet, and in particular to the population of Japan, including the more than 160,000 people displaced by the disaster, many of whom are still unable to return to their homes, and scores of millions more threatened had worst case scenarios occurred. One authoritative voice that has been central to exposing the myth-making of the nuclear industry and its supporters has been that of Kan Naoto, Prime Minister in 2011. His conversion from promoter to stern critic may be simple to understand, but it is no less commendable for its bravery. When the survival of half the society you are elected to serve and protect is threatened by a technology that is essentially an expensive way to boil water, then something is clearly wrong. Japan avoided societal destruction thanks in large part to the dedication of workers at the crippled nuclear plant, but also to the intervention of Kan and his staff, and to luck. Had it not been for a leaking pipe into the cooling pool of Unit 4 that maintained sufficient water levels, the highly irradiated spent fuel in the pool, including the entire core only recently removed from the reactor core, would have been exposed, releasing an amount of radioactivity far in excess of that released from the other three reactors. The cascade of subsequent events would have meant total loss of control of the other reactors, including their spent fuel pools and requiring massive evacuation extending throughout metropolitan Tokyo, as Prime Minister Kan feared. That three former Prime Ministers of Japan are not just opposed to nuclear power but actively campaigning against it is unprecedented in global politics and is evidence of the scale of the threat that Fukushima posed to tens of millions of Japanese.

The reality is that in terms of electricity share and relative to renewable energy, nuclear power has been in decline globally for two decades. Since the Fukushima Daiichi accident, this decline has only increased in pace. The nuclear industry knew full well that nuclear power could not be scaled up to the level required to make a serious impact on global emissions. But that was never the point. The industry adopted the climate-change argument as a survival strategy: to ensure extending the life of existing aging reactors and make possible the addition of some new nuclear capacity in the coming decades—sufficient at least to allow a core nuclear industrial infrastructure to survive to mid-century. The dream was to survive to mid-century, when limitless energy would be realized by the deployment of commercial plutonium fast-breeder reactors and other generation IV designs. It was always a myth, but it had a commercial and strategic rationale for the power companies, nuclear suppliers and their political allies.

The basis for the Fukushima Daiichi accident began long before March 11th 2011, when decisions were made to build and operate reactors in a nation almost uniquely vulnerable to major seismic events. More than five years on, the accident continues with a legacy that will stretch over the decades. Preventing the next catastrophic accident in Japan is now a passion of the former Prime Minister, joining as he has the majority of the people of Japan determined to transition to a society based on renewable energy. He is surely correct that the end of nuclear power in Japan is possible. The utilities remain in crisis, with only three reactors operating, and legal challenges have been launched across the nation. No matter what policy the government chooses, the basis for Japan’s entire nuclear fuel cycle policy, which is based on plutonium separation at Rokkasho-mura and its use in the Monju reactor and its fantasy successor reactors, is in a worse state than ever before. But as Kan Naoto knows better than most, this is an industry entrenched within the establishment and still wields enormous influence. Its end is not guaranteed. Determination and dedication will be needed to defeat it. Fortunately, the Japanese people have these in abundance. SB

The Interview

Q: What is your central message?

Kan: Up until the accident at the Fukushima reactor, I too was confident that since Japanese technology is of high quality, no Chernobyl-like event was possible.

But in fact when I came face to face with Fukushima, I learned I was completely mistaken. I learned first and foremost that we stood on the brink of disaster: had the incident spread only slightly, half the territory of Japan, half the area of metropolitan Tokyo would have been irradiated and 50,000,000 people would have had to evacuate.

Half one’s country would be irradiated, nearly half of the population would have to flee: to the extent it’s conceivable, only defeat in major war is comparable.

That the risk was so enormous: that is what in the first place I want all of you, all the Japanese, all the world’s people to realize.

Q: You yourself are a physicist, yet you don’t believe in the first analysis that people can handle nuclear power? Don’t you believe that there are technical advances and that in the end it will be safe to use?

Kan: As a rule, all technologies involve risk. For example, automobiles have accidents; airplanes, too. But the scale of the risk if an accident happens affects the question whether or not to use that technology. You compare the plus of using it and on the other hand the minus of not using it. We learned that with nuclear reactors, the Fukushima nuclear reactors, the risk was such that 50,000,000 people nearly had to evacuate. Moreover, if we had not used nuclear reactors—in fact, after the incident, there was a period of about two years when we didn’t use nuclear power and there was no great impact on the public welfare, nor any economic impact either. So when you take these factors as a whole into account, in a broad sense there is no plus to using nuclear power. That is my judgment.

One more thing. In the matter of the difference between nuclear power and other technologies, controlling the radiation is in the final analysis extremely difficult.

For example, plutonium emits radiation for a long time. Its half-life is 24,000 years, so because nuclear waste contains plutonium—in its disposal, even if you let it sit and don’t use it—its half-life is 24,000 years, in effect forever. So it’s a very difficult technology to use—an additional point I want to make.

Q: It figured a bit ago in the lecture by Professor Prasser, that in third-generation reactors, risk can be avoided. What is your response?

Kan: It’s as Professor Khwostowa said: we’ve said that even with many nuclear reactors, an event inside a reactor like the Fukushima nuclear accident or a Chernobyl-sized event would occur only once in a million years; but in fact, in the past sixty years, we’ve had Three Mile Island, Chernobyl, Fukushima. Professor Prasser says it’s getting gradually safer, but in fact accidents have happened with greater frequency and on a larger scale than was foreseen. So partial improvements are possible, as Professor Prasser says, but saying that doesn’t mean that accidents won’t happen. Equipment causes accidents, but so do humans.

Q: Today it’s five years after Fukushima. What is the situation in Japan today? We hear that there are plans beginning in 2018 to return the refugees to their homes. To what extent is the clean-up complete?

Kan: Let me describe conditions on site at Fukushima. Reactors #1, #2, #3 melted down, and the melted nuclear fuel still sits in the containment vessel; every day they introduce water to cool it. Radioactivity in the vessel of #2, they say, is 70 sieverts—not microsieverts or millisieverts, 70 sieverts. If humans approach a site that is radiating 70 sieverts, they die within five minutes. That situation has held ever since: that’s the current situation.

Moreover, the water they introduce leaves the containment vessel and is said to be recirculated, but in fact it mixes with groundwater, and some flows into the ocean. Prime Minister Abe used the words “under control,” but Japanese experts, including me, consider it not under control if part is flowing into the ocean. All the experts see it this way.

As for the area outside the site, more than 100,000 people have fled the Fukushima area.

So now the government is pushing residential decontamination and beyond that the decontamination of agricultural land.

Even if you decontaminate the soil, it’s only a temporary or partial reduction in radioactivity; in very many cases cesium comes down from the mountains, it returns.

The Fukushima prefectural government and the government say that certain of the areas where decontamination has been completed are habitable, so people have until 2018 to return; moreover, beyond that date, they won’t give aid to the people who have fled. But I and others think there’s still danger and that the support should be continued at the same level for people who conclude on their own that it’s still dangerous—that’s what we’re saying.

Given the conditions on site and the conditions of those who have fled, you simply can’t say that the clean-up is complete.

Q: Since the Fukushima accident, you have become a strong advocate of getting rid of nuclear reactors; yet in the end, the Abe regime came to power, and it is going in the opposite direction: three reactors are now in operation. As you see this happening, are you angry?

Kan: Clearly what Prime Minister Abe is trying to do—his nuclear reactor policy or energy policy—is mistaken. I am strongly opposed to current policy.

But are things moving steadily backward? Three reactors are indeed in operation. However, phrase it differently: only three are in operation. Why only three? Most—more than half the people—are still resisting strongly. From now on, if it should come to new nuclear plants, say, or to extending the licenses of existing nuclear plants, popular opposition is extremely strong, so that won’t be at all easy. In that sense, Japan’s situation today is a very harsh opposition—a tug of war—between the Abe government, intent on retrogression, and the people, who are heading toward abolishing nuclear reactors.

Two of Prime Minister Abe’s closest advisors are opposed to his policy on nuclear power.

One is his wife. The other is former Prime Minister Koizumi, who promoted him.

Q: Last question: please talk about the possibility that within ten years Japan will do away with nuclear power.

Kan: In the long run, it will disappear gradually. But if you ask whether it will disappear in the next ten years, I can’t say. For example, even in my own party opinion is divided; some hope to do away with it in the 2030s. So I can’t say whether it will disappear completely in the next ten years, but taking the long view, it will surely be gone, for example, by the year 2050 or 2070. The most important reason is economic. It has become clear that compared with other forms of energy, the cost of nuclear energy is high.

Q: Thank you. ”

Interview by Vincenzo Capodici

Introduction by Shaun Burnie

Translation by Richard Minear

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Tepco: Possible water leak at Fukushima plant during typhoon — The Asahi Shimbun

” Tokyo Electric Power Co. said Sept. 21 it will check for radiation contamination in seawater near its crippled Fukushima nuclear plant after heavy rain from Typhoon No. 16 brought tainted groundwater to the surface.

The water reached the top of wells at the Fukushima No. 1 nuclear power plant, and there is a possibility that some of it spilled into the sea.

“We will analyze the seawater because we cannot determine whether groundwater containing radioactive materials has actually leaked,” a TEPCO official said.

The official added that the company believes most of the water that may have poured into the sea was rainwater that had not seeped into the ground.

The utility constantly monitors groundwater levels in wells around the reactor buildings at the plant to prevent overflows.

TEPCO said groundwater in wells on the seaside area of the nuclear complex reached the surface around 10 p.m. on Sept. 20 amid the heavy rain brought by the approaching typhoon. The water kept rising despite workers’ efforts to lower the level using makeshift pumps and septic tank trucks.

The groundwater level remained the same as of 7 a.m. on Sept. 21 before it finally dropped to about 3 centimeters from the surface two hours later, the company said.

According to TEPCO, about 575 millimeters of rain fell in the area of the nuclear plant from Aug. 1 to Sept. 20. ”

by Kohei Tomida

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