AuthorTopic: Fukushima Clusterfuck Continues  (Read 62290 times)

Offline Surly1

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Radiation levels inside Fukushima high enough to kill robot sent to clean
« Reply #90 on: December 10, 2019, 05:37:50 AM »
Let's not forget the Olympics are in Tokyo. What could possibly go wrong?

Radiation levels inside Fukushima high enough to kill robot sent to clean

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December 6, 2019

A remote-controlled cleaning robot sent into a damaged reactor at Japan‘s Fukushima nuclear plant had to be removed Thursday before it completed its work because of camera problems most likely caused by high radiation levels.

It was the first time a robot has entered the chamber inside the Unit 2 reactor since a March 2011 earthquake and tsunami critically damaged the Fukushima Da-ichi nuclear plant.

Tokyo Electric Power Co. (TEPCO) said it was trying to inspect and clean a passage before another robot does a fuller examination to assess damage to the structure and its fuel. The second robot, known as the “scorpion,” will also measure radiation and temperatures.

Thursday‘s problem underscores the challenges in decommissioning the wrecked nuclear plant. Inadequate cleaning, high radiation and structural damage could limit subsequent probes, and may require more radiation-resistant cameras and other equipment, TEPCO spokesman Takahiro Kimoto said.

“We will further study (Thursday‘s) outcome before deciding on the deployment of the scorpion,” he said.

TEPCO needs to know the melted fuel‘s exact location and condition and other structural damage in each of the three wrecked reactors to figure out the best and safest ways to remove the fuel. It is part of the decommissioning work, which is expected to take decades.

The remote-controlled “cleaning” robot, bottom, was sent in to inspect and clean a passage for another robot in the damaged nuclear facility. (TEPCO/Associated Press)

During Thursday‘s cleaning mission, the robot went only part way into a space under the core that TEPCO wants to inspect closely. It crawled down the passage while peeling debris with a scraper and using water spray to blow some debris away. The dark brown deposits grew thicker and harder to remove as the robot went further.

More obstacles for second mission

After about two hours, the two cameras on the robot suddenly developed a lot of noise and their images quickly darkened — a sign of a problem caused by high radiation. Operators of the robot pulled it out of the chamber before completely losing control of it.

The outcome means the second robot will encounter more obstacles and have less time than expected for examination on its mission, currently planned for later this month, though Thursday‘s results may cause a delay.

Both of the robots are designed to withstand up to 1,000 Sieverts of radiation. The cleaner‘s two-hour endurance roughly matches an estimated radiation of 650 Sieverts per hour based on noise analysis of the images transmitted by the robot-mounted cameras. That‘s less than one-tenth of the radiation levels inside a running reactor, but still would kill a person almost instantly.

Kimoto said the noise-based radiation analysis of the Unit 2‘s condition showed a spike in radioactivity along a connecting bridge used to slide control rods in and out, a sign of a nearby source of high radioactivity, while levels were much lower in areas underneath the core, the opposite of what would normally be the case. He said the results are puzzling and require further analysis.

TEPCO officials said that despite the dangerously high figures, radiation is not leaking outside of the reactor.

Images recently captured from inside the chamber showed damage and structures coated with molten material, possibly mixed with melted nuclear fuel, and part of a disc platform hanging below the core that had been melted through.

https://livingstonledger.com/radiation-levels-inside-fukushima-high-enough-to-kill-robot-sent-to-clean/

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Offline RE

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☢️ Japan to start releasing Fukushima water into sea in 2 years
« Reply #91 on: April 13, 2021, 03:57:39 AM »
https://apnews.com/article/japan-tsunamis-tokyo-d35637331403c59bbdf61e5ee1f09dbc

Japan to start releasing Fukushima water into sea in 2 years
By MARI YAMAGUCHIan hour ago


1 of 14
Japanese Prime Minister Yoshihide Suga, left, attends a cabinet meeting at his official residence in Tokyo Tuesday, April 12, 2021. Japan’s government said Tuesday it has decided to start releasing massive amounts of radioactive water stored at the wrecked Fukushima nuclear plant in two years after treatment. Suga told that the government adopted the release to sea as “most realistic” and that the disposal of the water is “unavoidable in order to achieve Fukushima's recovery.” (Yoshitaka Sugawara/Kyodo News via AP)

TOKYO (AP) — Japan’s government announced Tuesday it would start releasing treated radioactive water from the wrecked Fukushima nuclear plant into the Pacific Ocean in two years. It’s a move that’s fiercely opposed by fishermen, residents and Japan’s neighbors.

The decision, long speculated at but delayed for years because of safety worries and protests, came during a meeting of Cabinet ministers who endorsed the ocean release as the best option.

The accumulating water has been stored in tanks at the Fukushima Daiichi plant since 2011, when a massive earthquake and tsunami damaged its reactors and their cooling water became contaminated and began leaking. The plant’s storage capacity will be full late next year.
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Prime Minister Yoshihide Suga said the ocean release was the most realistic option and that disposing the water is needed to complete the decades-long decommissioning of the Fukushima plant. He said the government would work to make sure the water is safe and to help local agriculture, fisheries and tourism.

The plant’s operator, Tokyo Electric Power Co., and government officials say tritium, which is not harmful in small amounts, cannot be removed from the water, but all other selected radionuclides can be reduced to releasable levels. Some scientists say the long-term impact on marine life from low-dose exposure to such large volumes of water is unknown.

The government stresses the water’s safety, calling it “treated” not “radioactive,” even though radionuclides can only be reduced to disposable levels, not to zero. The amount of radioactive material that would remain in the water is unknown.

Releasing the water into the ocean was described as the most realistic solution by a government panel that for nearly seven years had discussed how to dispose of the water. The report last year mentioned evaporation as a less desirable option.

Under the basic plan adopted Tuesday by the ministers, TEPCO will start releasing the water in about two years after building a facility and compiling release plans that follow safety requirements. It said the disposal of the water cannot be postponed further and is necessary to improve the environment surrounding the plant so residents can live there safely.

Residents, fisheries officials and environmental groups issued statements denouncing the decision as ignoring environmental safety and health, and further hurting Fukushima’s image and economy.

Japan Fisheries Cooperatives chairman Hiroshi Kishi said the decision less than a week after he met with Suga “trampled on” all Japanese fisheries operators.
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Local fisheries have just returned to full operation after a decade in which their catch was only for testing purposes, and they are struggling because of dwindling demand.

Protestors gathered outside the Prime Minister’s Office to demand the plan be scrapped.

TEPCO says its water storage capacity of 1.37 million tons will be full around fall of 2022. Also, the area now filled with storage tanks needs to be used for new buildings needed for removing melted fuel debris from inside the reactors and for other decommissioning work in coming years.

In the decade since the tsunami disaster, water meant to cool the nuclear material has constantly escaped from the damaged primary containment vessels into the basements of the reactor buildings. To make up for the loss, more water has been pumped into the reactors to continue to cool the melted fuel. Water is also pumped out and treated, part of which is recycled as cooling water, and the remainder stored in 1,020 tanks now holding 1.25 million tons of radioactive water.

Those tanks, which occupy a large space at the plant, interfere with the safe and steady progress of the decommissioning, Economy and Industry Minister Hiroshi Kajiyama said. The tanks also could be damaged and leak in case of another powerful earthquake or tsunami, the report said.

About 70% of the water in the tanks is contaminated beyond discharge limits but will be filtered again and diluted with seawater before it is released, the report says. According to a preliminary estimate, gradual release of the water will take nearly 40 years but will be completed before the plant is fully decommissioned.

IAEA Director General Rafael Mariano Grossi, in a video message, said the ocean discharge was in line with international practice, though “the large amount of water at the Fukushima plant makes it a unique and complex case.”

China and South Korea reacted strongly to Tuesday’s decision.

Koo Yun-cheol, minister of South Korea’s Office for Government Policy Coordination, said the plan was “absolutely unacceptable” and urged Japan to disclose how the water is treated and its safety is verified. South Korea has banned seafood imports from parts of Japan since 2013 and could increase those steps.

China criticized Japan’s decision as “extremely irresponsible,” saying it had not considered the health concerns of neighboring countries.
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