Dr. Caldicott on Fukushima: “Decommission or Cleaning Up? It’s Fantasy!”

This Week’s Featured Interview:

http://nuclearhotseat.com/2017/02/22/dr-caldicott-on-fukushima-at-6-decommission-or-cleaning-up-its-fantasy/

Fukushima: No End in Sight

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KGO Radio: Host Pat Thurston recently interviewed Arnie Gundersen, chief engineer for Fairewinds Energy Education on KGO radio to discuss the latest challenging news from Japan about the Fukushima Daiichi atomic power reactor including the high levels of radiation emanating from the reactors, all the failed robotic expeditions, where we should go from here, as well as how ongoing radioactive releases from the Fukushima Daiichi site may be impacting the west coast of the United States.

 

BBC Newsday: BBC Radio interviewed nuclear engineer Arnie Gundersen to discuss TEPCO’s attempts to send a special robot into Fukushima Daiichi Reactor #2 in Japan to investigate the obstacles in the way of TEPCO’s progress determining the location and condition of the atomic fuel. Unfortunately even this specially designed robot failed in its attempt to clear the path for additional investigations as the nuclear radioactivity was so high, it shut down the robots before they could complete their mission.

Listen Here

 

Enviro News: The astronomical radiation readings at Fukushima Daiichi Reactor #2 of 530 Sv/hr complicate the already complex task of decommissioning the plant. These levels are so radioactive that a human would be dead within a minute of exposure and specially designed robots can only survive for about 2 hours. Fairewinds chief engineer Arnie Gundersen says that the best solution would be to entomb the reactors, similar to the sarcophagus entombing Chernobyl, for at least 100-years, otherwise the radiation level that workers would be exposed to is simply too dangerous.
Read the whole article here

 

Follow The Money: Whats Up With Fukushima Decommissioning

 

Are the meltdowns at Fukushima Daiichi over? The answer is no. Made all the more prevalent a year out from it’s initial release by the recent robotic expeditions into Reactor #2 which gave us a clearer picture on just how deadly the radiation levels are, watch Chief Engineer and nuclear expert Arnie Gundersen inform viewers on what’s going on at the Japanese nuclear meltdown site, Fukushima Daiichi. As the Japanese government and utility owner Tokyo Electric Power Company push for the quick decommissioning and dismantling of this man-made disaster, the press and scientists need to ask, “Why is the Ukrainian government waiting at least 100 years to attempt to decommission Chernobyl, while the Japanese Government and TEPCO claim that Fukushima Daiichi will be decommissioned and dismantled during the next 30 years?”
Like so many big government + big business controversies, the answer has nothing to do with science, and everything to do with politics and money. To understand Fukushima Daiichi, you need to follow the money.

http://www.fairewinds.org/newsletter-archive//no-end-in-sight

Tepco uses radiation imaging drone at Fukushima Daiichi

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Tepco uses the RISER quadcopter drone to visually map gamma radiation in the unit 3 turbine building. The RISER quadcopter drone is equipped with GPS, HD cameras and the N-Visage 3D gamma radiation detector which produces color images of radiation. It has a small size 3d gamma camera.

The N-Visage 3D gamma radiation detector  technology has been used previously to examine the refueling floor of unit 2 and some other areas of the reactor buildings.

The RISER quadcopter drone has a maximum radiation resistance of 10 mSv/hr so it won’t be used into the more dangerous areas of the site.

Source: http://www.tepco.co.jp/nu/fukushima-np/handouts/2017/images1/handouts_170220_08-j.pdf

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Coming 6th Anniversary of the beginning of the still ongoing Fukushima Daiichi nuclear catastrophe

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Our Rainbow Warriors Facebook group started in 2011 as an FB group about the Fukushima catastrophe, its old name was the “Fukushima 311 Watchdogs”. In June 2012, after an exhausting first year the Fukushima 311 Watchdogsgroup  was dissolved, and one month later was reborn as the Rainbow Warriors, with a broader scope of interests, environment protection, climate change etc.  https://www.facebook.com/groups/277245265712386/
However the ongoing Fukushima catastrophe still remains one of our our major concerns.
The Fukushima 311 Watchdogs has survived as a community FB page:
Fukushima 311 Watchdogs https://www.facebook.com/fukushima311watchdog/
and as a blog: Fukushima 311 Watchdogs https://dunrenard.wordpress.com/

This coming March 11th will be the 6th Anniversary of the beginning of the still ongoing nuclear catastrophe. Many people have disappeared along the way since March 2011, however among those who were with us right from the beginning, the Fukushima Watchers, the Fukushima Watchdogs, some haven’t yet forgotten  and are still here with us.

3.11.2017 FUKUSHIMA SIXTH ANNIVERSARY ONGOING DISASTER.
TAKE ACTION: #FUKU+6 Anniversary is happening 3.11.17 … six years since the #Fukushima nuclear meltdown and ongoing poisoning of our oceans began … our air land food water have been contaminated. #Fukushima continues to spew radioisotopes into the Pacific Ocean threatening vital marine life, ecosystems and the food chain. Japan continues to burn radioactive debris and dump it into the Pacific spreading poison into the atmosphere. Join the FUKU+6 actions and events fb page taking place worldwide. Act in solidarity, please click on this image, download it, and make it your cover pic, and help spread the word. https://www.facebook.com/groups/3.11fukushimasixthanniversaryactions/601393323403623/?ref=notif&notif_t=like&notif_id=1487640969842420

FOCUS: Failed Survey Complicates N-Fuel Removal at Fukushima Plant

It looks like its too radioactive for robots to survive. I wonder how they will do this work now?

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Tokyo, Feb. 20 (Jiji Press)–A failed robot survey of melted nuclear fuel that has dropped through the bottom of a damaged reactor pressure chamber at the Fukushima No. 1 nuclear plant complicates the formulation of a policy in the summer for taking out the fuel debris.
The removal of the molten nuclear fuel is regarded as the most demanding challenge in the decommissioning of the disaster-stricken plant’s reactors, said to take 30 to 40 years.
Tokyo Electric Power Company Holdings Co. <9501>, the manager of the plant in Fukushima Prefecture, northeastern Japan, is discussing the drawing up of a broad policy outline before conducting an additional survey to work out a detailed plan for the nuclear fuel removal, company officials said.
TEPCO’s initial plan called for a self-propelled survey robot, dubbed scorpion, to enter the No. 2 reactor’s containment vessel and travel on a 7.2-meter rail to reach a metal grating directly beneath the reactor’s damaged pressure chamber. The robot would have surveyed the extent of damage to the chamber, while locating melted nuclear fuel that is believed to have dropped through the metal grating to the bottom of the containment vessel and shooting the fuel’s images.
The No. 2 reactor is one of the three units that suffered meltdown due to the failure of their cooling systems caused by the March 2011 earthquake and tsunami.

http://jen.jiji.com/jc/eng?g=eco&k=2017022000007

Radiation levels at Fukushima reactor puzzle nuclear experts

It is unclear why there is less radioactivity under the reactor vessel, when it is where there should be the most.

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A robot was expected to solidify ways to clean up the No. 2 reactor at the Fukushima No. 1 nuclear plant, but its short-lived mission raised puzzling questions that could derail existing decommissioning plans.

The robot, Sasori, was abandoned in the melted-down reactor after it became stuck in deposits and other debris that are believed to have interfered with its drive system.

But it did take radiation measurements that indicate Tokyo Electric Power Co., operator of the plant, was too optimistic about the state and location of the melted fuel within the reactor. The melted fuel, in fact, may be spread out all over the reactor’s containment vessel.

Scientists had believed the melted nuclear fuel fell through the reactor’s pressure vessel and landed on metal grating and the floor of the containment vessel.

The results of Sasori’s investigation, coupled with previous data taken from possible images of the melted fuel, show the situation within the reactor is much worse than expected. And a fresh investigation into the reactor is now nowhere in sight.

A remote-controlled video camera inserted into the reactor on Jan. 30 took what are believed to be the first images of melted fuel at the plant, which suffered a triple meltdown after the March 2011 Great East Japan Earthquake and tsunami.

Based on the images, TEPCO estimated 530 sieverts per hour at a point almost halfway between the metal grating directly beneath the pressure vessel and the wall of the containment vessel. Black lumps on the grating are believed to be melted fuel.

A different robot sent in on Feb. 9 to take pictures and prepare for Sasori’s mission estimated 650 sieverts per hour near the same spot.

Both 530 and 650 sieverts per hour can kill a person within a minute.

Sasori, equipped with a dosimeter and two cameras, on Feb. 16 recorded a reading of 210 sieverts per hour near the same location, the highest figure measured with instruments in the aftermath of the disaster.

Sasori was supposed to travel along a rail connecting the outer wall of the containment vessel with the metal grating to measure radiation doses and shoot pictures inside, essential parts of work toward decommissioning the reactor.

After traveling only 2 meters, the robot became stuck before it could reach the metal grating.

TEPCO at a news conference repeatedly said that Sasori’s investigation was not a “failure” but had produced “meaningful” results.

However, an official close to TEPCO said, “I had great expectations for Sasori, so I was shocked by how it turned out.”

Hiroaki Abe, professor of nuclear materials at the University of Tokyo who has studied TEPCO’s footage, tried to explain why high doses were estimated between the pressure vessel and the containment vessel.

Instead of directly landing on the rail, the melted nuclear fuel may have flown off after it reacted violently with the concrete, which had a high moisture content, at the bottom of the containment vessel, just like what happens when lava pours into the sea,” Abe said.

But he said this scenario raises a puzzling question, considering the estimated radiation readings near the area below the pressure vessel were down to 20 sieverts per hour, according to an analysis of the video footage.

If nuclear fuel debris had splattered around, the radiation levels at the central area below the pressure vessel must be extremely high,” he said. “In addition, deposits on the rail would have taken the shape of small pieces if they were, in fact, flying nuclear fuel debris. The findings are puzzling.”

Images by the remote-controlled camera also showed that equipment in the lower part of the pressure vessel was relatively well preserved, indicating that the hole at the bottom of the vessel is not very large.

How to remove nuclear fuel debris will all depend on how much remains inside the pressure vessel and how much fell out,” Abe said.

Toru Obara, professor of nuclear engineering at the Tokyo Institute of Technology, stressed the need to retrieve substances from the bottom of the robots or elsewhere.

We could get clues as to the state of the melted nuclear fuel and the development of a meltdown if we could figure out which materials mixed with the nuclear fuel,” he said.

The surveys by the camera and robots were conducted from a makeshift center at the No. 2 reactor. The center’s walls are made from radiation-blocking metal.

TEPCO and the government plan to determine a method to remove nuclear fuel debris in fiscal 2018 before they proceed with the actual retrieval process at one of the three destroyed reactors.

One possible method involves filling the containment vessels with water to prevent radioactive substances from escaping.

http://www.asahi.com/ajw/articles/AJ201702190042.html

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Melted Nuclear Fuel Search Proceeds One Dead Robot at a Time

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The latest robot seeking to find the 600 tons of nuclear fuel and debris that melted down six year ago in Japan’s wrecked Fukushima Dai-Ichi power plant met its end in less than a day.

The scorpion-shaped machine, built by Toshiba Corp., entered the No. 2 reactor core Thursday and stopped 3 meters (9.8 feet) short of a grate that would have provided a view of where fuel residue is suspected to have gathered. Two previous robots aborted similar missions after one got stuck in a gap and another was abandoned after finding no fuel in six days.

After spending most of the time since the 2011 disaster containing radiation and limiting ground water contamination, scientists still don’t have all the information they need for a cleanup that the Japanese government estimates will take four decades and cost 8 trillion yen ($70.6 billion). It’s not yet known if the fuel melted into or through the containment vessel’s concrete floor, and determining the fuel’s radioactivity and location is crucial to inventing the technology needed to remove it. 

The roadmap for removing the fuel is going to be long, 2020 and beyond,” Jacopo Buongiorno, a professor of nuclear science and engineering at the Massachusetts Institute of Technology, said in an e-mail. “The re-solidified fuel is likely stuck to the vessel wall and vessel internal structures. So the debris have to be cut, scooped, put into a sealed and shielded container and then extracted from the containment vessel. All done by robots.”

Read more: Robots are being utilized to clean up U.K.’s nuclear waste

To enter a primary containment vessel, which measures about 20 meters at its widest, more than 30 meters tall and is encased in meters of concrete, outside air pressure is increased to keep radiation from escaping and a sealed hole is opened that the robot passes through. Three reactors at the plant suffered meltdowns, and each poses different challenges and requires a custom approach for locating and removing the fuel, said Tatsuhiro Yamagishi, Tokyo Electric Power Co. Holdings Inc. spokesman.

The machines are built with specially hardened parts and minimal electronic circuitry so that they can withstand radiation, if only for a few hours at a time. Thursday’s mission ended after the robot’s left roller-belt failed, according to Tokyo Electric, better known as Tepco. Even if it had returned, this robot, like all others so far designed to aid the search for the lost fuel, was expected to find its final resting place inside a reactor.

No. 1 Unit

Hitachi Corp. in the next two months plans to send a machine into the No. 1 reactor core that scientists hope can transmit photos of the fuel and measure radiation levels.

The snake-like robot will lower a camera on a wire from a grate platform in the reactor to take photos and generate 3-D models of the bottom of the containment vessel. This will be the third time Hitachi sends in this robot design.

While the company is hopeful this robot will find some of the fuel, it will likely be unable to find all of it, according to Satoshi Okada, a Hitachi engineer working on the project. The company is already planning the next robot voyage for after April.

We are gathering information so that we can decide on a way to remove the fuel,” said Okada. “Once we understand the situation inside, we will be able to see the way to remove the fuel.”

No. 2 Unit

On Thursday, Toshiba’s scorpion-like robot entered the reactor and stopped short of making it onto the containment vessel’s grate. While Tepco decided not to retrieve it, the company views the attempt as progress.

We got a very good hint as to where the fuel could be from this entire expedition” Tepco official Yuichi Okamura said Thursday at a briefing in Tokyo. “I consider this a success, a big success.”

Tepco released images last month of a grate under the No. 2 reactor covered in black residue that may be the melted fuel — one of the strongest clues yet to its location. The company measured radiation levels of around 650 sieverts per hour through the sound-noise in the video, the highest so far recorded in the Fukushima complex.

A short-term, whole-body dose of over 10 sieverts would cause immediate illness and subsequent death within a few weeks, according to the World Nuclear Association.

The Hitachi and Toshiba robots are designed to handle 1,000 sieverts and no robot has yet been disabled due to radiation.

Radiation levels near the fuel are lethal,” said MIT’s Buongiorno, who holds the university’s Tepco chair, a professorship based on an initial donation by the company 10 years ago. There are no formal affiliations or obligations for the faculty who receive the chair, he said.

Because the No. 2 unit is the only one of the three reactors that didn’t experience a hydrogen explosion, there was no release into the atmosphere and radiation levels inside the core are higher compared to the other two units, according to the utility.

No. 3 Unit

Tepco’s balance sheet has been strapped by ballooning Fukushima cleanup costs and slumping national power demand. All of the company’s nuclear power plants remain shut since it halted the No. 6 reactor at its Kashiwazaki Kariwa station in March 2012. The company is seeking drastic changes in top management in consultation with the Japanese government, TV Asahi reported Friday, without attribution.

The utility has focused on removing spent fuel in the upper part of the reactor building, which Toshiba aims to extract with a claw-like system. This fuel didn’t melt and is still in a pool that controls its temperature.

The used-fuel in No. 3 is scheduled to begin removal before the end of the decade, the first among the three reactors that melted down. Toshiba is developing another robot to search for melted fuel, planned to enter sometime in the year ending March 2018. The company hasn’t announced yet the design or strategy.

https://about.bnef.com/blog/race-for-japans-melted-nuclear-fuel-leaves-trail-of-dead-robots/