Fukushima nuclear plant: Tsunami wall could have avoided disaster but boss scrapped the plan, employee testifies — Newsweek

” A worker for the plant involved the 2011 Fukushima nuclear disaster said in a Japanese court Wednesday that his former boss was warned that a massive tsunami could strike the site, but delayed measures to build a protective wall to prevent it.

An unnamed employee of the Tokyo Electric Power Company (TEPCO) that owns the ruined Fukushima Daiichi or No.1, Nuclear Power Plant testified during a trial this week that a 2008 safety test showed an earthquake could cause a tsunami as high as 52 feet capable of pounding the coastal facility, according to The Asahi Shimbun. The company was initially set to build a seawall, but the employee told the court that former TEPCO Vice President Sakae Muto suddenly dismissed the idea.

The potentially catastrophic scenario was brought up again during a meeting on March 7, 2011, compelling shocked regulators to again recommend a wall to shield the facility, The Japan Times reported. But it was too late already: A magnitude 9.0 earthquake and tsunami struck only four days later on March 11, 2011, leaving up to 18,500 people dead or missing and destroying the facility.

Three out of the six nuclear reactors at the Fukushima No.1 plant suffered devastating meltdowns. Muto, along with former TEPCO Chairman Tsunehisa Katsumata and former TEPCO Vice President Ichiro Takekuro were indicted in February 2016 and are facing trial for suspected professional negligence resulting in death or injury after the worst nuclear disaster since the Chernobyl incident in 1986.

The multi-billion dollar effort to recover the site is far past schedule and over budget, but the TEPCO has claimed some recent successes. Six years after the disaster, the melted nuclear fuel was finally founded at the bottom of the partially submerged reactors. The site was so radioactive, even the robots previously sent it could not traverse the deadly core.

Efforts to retrieve the fuel, however, have been hampered as the $324 million ice wall that penetrated 100 feet into the earth failed to stop groundwater from leaking into the site, as Reuters reported last month. In fact, the amount of groundwater seeping into the facility may have increased since the highly-anticipated ice wall was installed last August, amounting to the latest setback in a cleanup process already beset by seemingly endless complications and miscalculations.

Removing this water adds to an already growing storage crisis on the site. TEPCO deliberately added water to cool off the plant’s damaged reactors. After coming in contact with the plant, the coolant water and groundwater became tainted with a substance known as tritium, a byproduct of the nuclear process notoriously difficult to filter out of water. TEPCO has accumulated over 1 million tons of this tritium-laced water in 650 giant tanks, according to The Japan Times, and is urging the government to let the company begin dumping it into the ocean.

Some locals have protested this, however. While tritium was a natural byproduct of the nuclear process that experts have described as harmless in smaller doses and was dumped into oceans worldwide, Fukushima activists and fishermen have argued that dumping tritium, even in small quantities, would further hurt the reputation of the region, still synonymous with nuclear disaster. Nearby China and South Korea are among the nations that still restrict the import of certain products from Japan.

Lingering concerns about radiation have also reportedly kept many of the 160,000 residents that fled Fukushima from returning. Life, nevertheless, has begun to return to some parts of the crisis-stricken prefecture. The town of Okuma announced Wednesday that some citizens would be allowed to stay overnight starting next week for the first time since the March 2011 disaster, Japanese daily The Mainichi Shimbun said. ”

by Tom O’Connor, Newsweek

source with image and internal links

The nuclear disaster at Fukushima didn’t have to happen — The Washington Post

” After a devastating tsunami left 18,000 people dead in 2011, Japan was about to face a potentially more significant disaster as several reactors at the Fukushima Daiichi nuclear power plant started to melt down. More than 300,000 people were evacuated.

Since then, the Japanese government has tried to defend the Tokyo Electric Power Co. (TEPCO), which operated the plant, and offer reassurances that the country’s nuclear reactors are secure. A study released Monday in the science journal Philosophical Transactions reaches a different conclusion, however: “The Fukushima accident was preventable, if international best practices and standards had been followed, if there had been international reviews, and had common sense prevailed in the interpretation of preexisting geological and hydrodynamic findings.”

The study’s authors paint a bleak picture of TEPCO’s failures before the disaster, as well as the company’s handling of the crisis. Using documents provided by the U.S. National Research Council, the U.S. Nuclear Regulatory Commission, Japan’s bicameral legislature and TEPCO itself, they conclude: “Had the TEPCO modellers had any experience with tsunamis, they would have had immediately recognized that their ‘high’ resolution predictions were underestimating the hazard.”

Researchers Costas Synolakis and Utku Kanoglu allege that the accident revealed striking inaccuracies in TEPCO’s internal risk analysis, as well as a “cascade of engineering and regulatory failures.”

“The entire experience with TEPCO’s pre-event internal studies not to mention the entire methodology that has been used in Japan to assess tsunami hazards points to the perils of insularity,” the study’s authors wrote.

According to Synolakis and Kanoglu, TEPCO researchers had long known that earthquakes could threaten power plants in the region. Despite that, necessary safety measures were not implemented.

The researchers also question the designs of some Japanese nuclear power plants, which could leave certain structures more vulnerable than others. “Interestingly, while the Onagawa [nuclear power plant] was also hit by a tsunami of approximately the same height as Dai-ichi, it survived the event ‘remarkably undamaged.’” The differences in vulnerability could partially be due to methodological mistakes “which almost nobody experienced in tsunami engineering would have made,” according to Synolakis and Kanoglu, who warn that similar flaws could lead to more accidents in the future.

“When it comes to studying hazards or designing structures whose catastrophic failure will transcend national boundaries, even countries with sophisticated technologies need to take note of Godel’s incompleteness theorem,” they wrote, referring to a mathematical concept most commonly interpreted as signifying the limits of provability.

Regulatory measures could have prevented the 2011 accident, but the researchers found “substantial inadequacies” there, as well.

The allegations are among the most extensive — but they are far from being the first. The Japanese government under the leadership of Shinzo Abe has refuted allegations of structural failures in the past and said that its response to the disaster had been adequate. Shortly afterward, the government decided to restart many of the country’s nuclear power plants, despite protests and safety concerns.

Meanwhile in Fukushima, the nuclear power plant is far from being secured: Hundreds of fuel rods stored nearby have not been removed. ”


*Document shows Tepco recognized risk of huge tsunami at Fukushima plant in 2008 — The Asahi Shimbun

” Tokyo Electric Power Co. in 2008 recognized the “indispensable” need for countermeasures against a towering tsunami at the Fukushima No. 1 nuclear plant, but it ended up doing nothing, an internal document showed.

The document was disclosed on June 18 by TEPCO, operator of the Fukushima plant, at the request of its shareholders who have filed a lawsuit against the utility’s executives. The plaintiffs are demanding that company executives be held responsible for the nuclear crisis at the plant that was triggered by the March 2011 Great East Japan Earthquake and tsunami.

“It is indispensable for us to develop measures against a higher tsunami than currently estimated,” the document says.

The plaintiffs argue that the document proves that TEPCO executives at the time could foresee the possibility of a huge tsunami striking the nuclear plant. They say the utility in 2008 estimated a 15.7-meter tsunami could hit the plant based on earthquake predictions by a governmental organization.

But TEPCO said its 2008 estimate could not be “a factor that inevitably forced them to take concrete countermeasures because there were differences of opinion, even among experts, on how to estimate a quake.”

The in-house document was distributed during a TEPCO meeting held on Sept. 10, 2008, to discuss countermeasures at the Fukushima nuclear plant against earthquakes and tsunami.

Akio Komori, a managing executive officer and director of the plant at that time, attended the meeting.

The document says it is “difficult to completely deny” the government findings on a possible earthquake and tsunami, and that the company had “no choice but” to raise the maximum height in its estimates for tsunami.

According to the shareholders suing the TEPCO officials, the document includes a sentence that says, “This contains sensitive information and must be returned.”

In another document submitted to the Tokyo District Court by TEPCO in the lawsuit, the company says, “The (2008) document just mentioned the possibility of some sort of anti-tsunami measures required in the future and did not point out any specific risk of tsunami.” ”


IAEA report on Fukushima slams lack of tsunami preparedness despite awareness of threat — The Japan Times

” VIENNA – The International Atomic Energy Agency criticized Tokyo Electric Power Co. and Japanese regulatory authorities for their failure to prevent the 2011 Fukushima No. 1 nuclear plant disaster despite knowing the risk of large tsunami hitting the facility, according to a copy of an IAEA report.

The U.N. nuclear watchdog said in the final report on the nuclear disaster triggered by a huge earthquake and tsunami in March 2011, obtained Sunday, that “the Fukushima Daiichi (No. 1) NPP (nuclear power plant) had some weaknesses which were not fully evaluated by a probabilistic safety assessment, as recommended by the IAEA safety standards.”

The paper, compiled by around 180 experts from 42 countries, is set to be submitted to the IAEA’s annual meeting in September after its board examines the 240-page summary in June.

The report addressing the causes and consequences of the Fukushima disaster as well as lessons learned is expected to serve as a reference for nuclear safety measures worldwide.

The IAEA said a new approach applied between 2007 and 2009 postulated a magnitude-8.3 quake off the coast of Fukushima that could lead to tsunami of around 15 meters hitting the No. 1 plant and inundating the main buildings.

Despite the analysis, Tepco, the old Nuclear and Industrial Safety Agency, which oversaw Japan’s nuclear industry at that time, and other organizations did not act, deciding instead that “further studies and investigations were needed.”

“Tepco did not take interim compensatory measures in response to these increased estimates of tsunami height, nor did NISA require Tepco to act promptly on these results,” the report says.

“Prior to the accident, there was not sufficient consideration of low probability, high consequence external events which remained undetected. This was in part because of the basic assumption in Japan, reinforced over many decades, that the robustness of the technical design of the nuclear plants would provide sufficient protection against postulated risks,” it says.

As a result, Tepco did not implement a sufficient safety assessment as recommended by the IAEA and lacked protection for the emergency diesel generators, battery rooms and other vital systems against tsunami-caused flooding, the paper adds.

“The operators were not fully prepared for the multiunit loss of power and the loss of cooling caused by the tsunami. Although Tepco had developed severe accident management guidelines, they did not cover such an unlikely combination of events,” the report says, also pointing to the lack of appropriate training for workers at the plant.

The IAEA called on countries that use, or plan to use, nuclear power to make continuous efforts to improve safety based on new findings and to be prepared to cope with natural disasters more severe than those predicted when nuclear power plants were designed. ”