Failure « nuclear-news

Nuclear plant cooling system stops working for 8 hours.

July 3, 2022

The operator of a nuclear fuel reprocessing plant in Aomori Prefecture, northern Japan, says a cooling system for highly radioactive waste liquid stopped functioning for about eight hours on Saturday.

Japan Nuclear Fuel Limited reported the problem at a plant compound in Rokkasho Village on Sunday. It says the glitch poses no threat to the environment.

The operator says one of the tanks storing radioactive waste lost its cooling functions for about eight hours from around 3:30 p.m.

About 2,600 liters of waste liquid produced during a test operation was stored in the tank.

The operator says it found cooling water levels dropping at around 7 p.m. on Saturday. An inspection discovered that the valve of a circulating water piping system had been turned off for some reason.

The operator said the temperature of the waste liquid briefly rose to 32 degrees from the usual 24 degrees. It says there is no leakage of radioactive substances.

The operator said it officially confirmed at 2:26 a.m. on Sunday that the cooling function had stopped working, explaining why it announced the problem one day after it occurred.

The Aomori prefectural government has dispatched officials to the plant and urged the operator to determine the cause of the problem and come up with measures to prevent a recurrence.

https://www3.nhk.or.jp/nhkworld/en/news/20220703_13/?fbclid=IwAR1dHhAMhirNMcq_ndCEeUpaA2J_TvIcXiEWlAsV0-G4aen9g8yPVHjc6i4

July 10, 2022 Posted by dunrenard | Japan | Cooling System, Failure, Rokkasho NPP | Leave a comment

Decade after Fukushima disaster, decontamination work remains incomplete in 85% of regions

Greenpeace says Japan should suspend returning residents to the afflicted region

Mar.5,2021

Decontamination work remains incomplete in 85% of regions where the Japanese government claims to have removed radioactive contaminants from the Fukushima Nuclear Power Plant disaster, an international environment group’s analysis shows.

In a report titled “Fukushima Daiichi 2011-2021,” published on Thursday ahead of the 10th anniversary of the disaster on March 11, Greenpeace urged the Japanese government to discontinue its policy of returning residents to the afflicted region without regard for science-based analysis.

Two weeks after the disaster struck in March 2011, the group sent a team of radioactivity exports to the scene in the first of 32 total visits through November 2020 to survey the radiation impacts in the Fukushima region. The recent report was based on its findings to date.

The Japanese government has announced the completion of most decontamination work for a Special Decontamination Area (SDA), which does not include a region close to the plant with particularly high levels of contamination that prevent residents from returning. Carried out through March 2019, the effort involved a commitment of 30 million person-hours and cost US$28 billion.

But an analysis of government data by Greenpeace showed that of the 840 square kilometers in the SDA, actual decontamination work had only been completed on 120 square kilometers, or 15 %.

In the case of Iitate — the largest of the seven administrative districts located entirely inside the SDA — decontamination had yet to be completed for 18,183 hectares, or 79% of its area. In the second-largest district of Namie, just 2,140 hectares, or 10%, had undergone even some decontamination.

Resident evacuation orders for the two regions were lifted in March 2017 — but according to Greenpeace, radiation levels make them still too dangerous for human habitation.

According to a Greenpeace study last November, the average amount of radiation in five out of 11 sites surrounding one home in Iitate was 0.5 microsieverts per hour (μSv/h), exceeding the government’s target of 0.23μSv/h.

The area immediately outside of one Namie school was found to be open to the general public despite 93% of measured sites showing radiation above the government’s targets.

“The fact that 85% of the contaminated surface area of the seven Fukushima districts inside the SDA has not been subject to decontamination is directly related to the radiological hazards posed by the mountainous forested areas,” the report explained.

“These remain a long-term source of contamination, including recontamination,” it warned.

Shaun Burnie, the Greenpeace senior nuclear specialist responsible for writing the report, urged the Japanese government to immediately suspend its return policy and decontamination program in order to protect residents of the Fukushima region, arguing that they ignore science-based analysis.

The same day, Greenpeace also published a technical report analyzing the decommissioning of the Fukushima Daiichi reactor. In it, Greenpeace proposed that the Japanese government adopt an alternative to its current decommissioning plan, which increases the amount of water contaminated with high-level radioactive material.

As an alternative approach, it suggested replacing water with air as a means of cooling reactor core fuel, while reducing the amount of contaminated water by installing moats to prevent seawater and underground water infiltration around the plant.

Chang Ma-ri, a climate energy campaigner for Greenpeace, said, “The ravages of radioactive contamination caused by the Fukushima disaster will pose a burden on humankind that will not be resolved for the next century or more.”

“The Japanese government needs to start by withdrawing its imminent plans for the release of contaminated water [into the ocean],” she urged.

By Kim Jeong-su, senior staff writer

http://english.hani.co.kr/arti/english_edition/e_international/985626.html

March 6, 2021 Posted by dunrenard | Fukushima 2021 | decontamination, Failure, Fukushima Prefecture | Leave a comment

Decade after Fukushima disaster, Greenpeace sees cleanup failure

Greenpeace has recommended that Japan suspend the current return policies, which it says “ignore science-based analysis, including potential lifetime exposure risks to the population” and abandon plans to lift evacuation orders in six municipalities

(FILES) This handout file picture taken and received by Tokyo Electric Power Co (TEPCO) on April 10, 2011 shows an aerial view of the first reactor building of TEPCO’s No.1 Fukushima nuclear power plant in the town of Okuma in Fukushima prefecture, two months after the earthquake and tsunami hit the region on March 11, 2011. – Ten years after the Fukushima disaster, Japan’s nuclear industry remains crippled, with the majority of the country’s reactors halted or on the path towards decommissioning.

Mar 4, 2021

Ten years after the worst nuclear accident since Chernobyl, land Japan identified for cleanup from the triple reactor meltdown of the Fukushima No. 1 power plant remains contaminated, according to a report from Greenpeace.

On average, just 15% of land in the “Special Decontamination Area,” which is home to several municipalities, has been cleaned up, according to the environmental advocacy group’s analysis of government data. That’s despite the government’s claims that the area has largely been decontaminated, the group said.

In addition, Greenpeace said its own radiation surveys conducted over the last decade have consistently found readings above government target levels, including in areas that have been reopened to the public. The lifting of evacuation orders in places where radiation remains above safe levels potentially exposes people to an increased risk of cancer, the report said.

“The contamination remains and is widespread, and is still a very real threat to long term human health and the environment,” the report said.

Japan’s Ministry of Environment wasn’t immediately available for comment. Decontamination efforts have reduced radiation levels in residential areas by an average of 76%, according to the ministry’s website, which has compiled monitoring data through 2018. Fukushima Prefecture wasn’t immediately available for comment.

More than 160,000 people were evacuated from the area surrounding the Fukushima nuclear plant after a magnitude 9 earthquake, the biggest ever recorded to hit Japan, caused a massive tsunami that overwhelmed the plant. While the government has been steadily lifting evacuation orders on towns since 2014, roughly 36,000 people are still displaced.

Greenpeace recommended that Japan suspend the current return policy, which “ignore science-based analysis, including potential lifetime exposure risks to the population” and abandon plans to lift evacuation orders in six municipalities.

https://www.japantimes.co.jp/news/2021/03/04/national/fukushima-greenpeace-radiation-health-3-11/

March 6, 2021 Posted by dunrenard | Fukushima 2021 | Clean-up, decommissioning, Failure, Fukushima Daiichi | Leave a comment

TEPCO bungles it again in dealing with Fukushima tainted water

Rows of tanks store water contaminated by radioactive materials at the Fukushima No. 1 nuclear power plant

October 9, 2018

Disturbing new revelations about increasing amounts of radioactive water at the Fukushima No. 1 nuclear power plant have undoubtedly further darkened the already dim prospects for solving this tricky and complicated challenge.

Tokyo Electric Power Co. (TEPCO), the operator of the nuclear plant destroyed by the 2011 earthquake and tsunami disaster, has said the filtering system to decontaminate the polluted water, known as ALPS (advanced liquid processing system), has failed to remove such radioactive elements as strontium 90 and radioactive iodine.

On Sept. 28, the utility acknowledged that about 80 percent of the water in storage tanks for ALPS-treated water on the plant premises exceeded government standards for radioactive materials.

TEPCO previously claimed that the ALPS system could remove all radioactive elements except for tritium, a mildly radioactive isotope of hydrogen.

But the fact is that of the 890,000 tons of water treated by the ALPS system and stored in the tanks, about 750,000 tons contain higher concentrations of radioactive materials than levels permitted by the safety regulations for release into the ocean.

In 65,000 tons of treated water, the levels of strontium 90 are more than 100 times the safety standards, according to TEPCO. The levels are as high as 20,000 times the standards in some tanks.

In explaining the reasons for this failure, TEPCO pointed to problems with the ALPS system shortly after it was first installed. The utility also reduced the frequency of the replacement of absorbents for removing radioactive materials to keep the system running as long as possible.

The company had long known these facts, but was less than eager to share them with the public.

TEPCO says it has disclosed the data on its website. But it is virtually impossible for an uninformed third-party information seeker to detect such problems in the massive reams of data.

The company deserves to be criticized for having deliberately concealed these inconvenient facts.

The utility reported the facts to an industry ministry subcommittee dealing with the problem of radioactive water and apologized. It appears that the company is not yet fully aware of its responsibility to solve this problem as the operator of the plant where an unprecedented nuclear accident occurred.

The ministry, for its part, should be held accountable for its failure to ensure appropriate disclosure of the information by TEPCO. The subcommittee should be faulted for concentrating its attention almost exclusively on tritium.

Tackling this formidable challenge requires debate from a broad perspective based on diverse information.

This point has been underscored afresh by the latest revelations.

The consequent radical changes in the basic assumptions concerning the problem of radioactive water have brought the process of figuring out a workable way to deal with the challenge back to square one.

TEPCO plans to treat the contaminated water with the ALPS system again to lower the levels of radioactive materials below the safety standards.

This approach, however, is expected to make the water treatment process far costlier and more time-consuming than originally expected, possibly affecting the entire project to decommission the crippled reactors at the plant.

The biggest blow comes from the serious damage the revelations have caused to TEPCO’s already strained relationship with local communities.

To build a broad consensus on how to cope with the problem, the government and the utility should work together to ensure timely and adequate information disclosure and set up opportunities for dialogue with local residents.

A system should also be created to promote a national conversation on this issue.

The tanks to store treated water is expected to be filled to capacity by around 2020, according to the government.

But no time limit should be set for debate on the problem. There is no shortcut to a solution.

http://www.asahi.com/ajw/articles/AJ201810090025.html

October 12, 2018 Posted by dunrenard | Fukushima 2018 | Admission, ALPS System, Failure, Fukushima Daiichi, Radioactive Water | Leave a comment

Fukushima ice wall failing to deliver on promise

This Feb. 9 photo shows the crippled No. 3 unit of the Fukushima Daiichi nuclear power plant

TOKYO — Six months since the work began, the “ice wall” has failed to produce its intended results as groundwater continues to flow in and out of damaged facilities at the Fukushima Daiichi nuclear power plant.

An encircling wall of frozen soil, created by pumping a subzero coolant through underground pipes, is getting closer to completion, the Japanese government and plant operator Tokyo Electric Power Co. Holdings reported Tuesday at a meeting of experts convened by the Ministry of Economy, Trade and Industry.

The ocean-facing side of the wall is nearly finished, though gaps remain on the inland side, officials reported. Some of the expert panelists questioned the basis for determining such progress.

Groundwater runs down from the highland and seeps into the damaged reactor buildings, where it becomes tainted with radioactive material before flowing out into the ocean. The frozen wall has been built to stop this flow. But the problem was exacerbated by heavy rains starting around mid-August, as northern Japan was swept by multiple typhoons. This resulted in massive amounts of groundwater rushing into plant buildings, making it difficult to assess the wall’s effectiveness.

The operator, Tepco, thinks the inflows are concentrated at seven unfrozen sections on the inland side. Kunio Watanabe, an associate professor of environmental science at Mie University, blames the utility for having “fallen behind in its responses to address problems” at the Fukushima plant.

“If dealing with the contaminated water takes too long,” warns Masashi Kamon, professor emeritus at Kyoto University, “the entire decommissioning process may be set back.”

More than five and a half years have gone by since the March 2011 earthquake and tsunami that crippled Fukushima Daiichi.

The government and Tepco hope to complete the wall soon. But some outside experts at a meeting held by Japan’s nuclear regulator last month declared the effort a failure.

http://asia.nikkei.com/Japan-Update/Fukushima-ice-wall-failing-to-deliver-on-promise/

September 29, 2016 Posted by dunrenard | Fukushima 2016 | Failure, Fukushima Daiichi, Ice wall | 1 Comment