Boss Byproducts: Corium Is Man-Made Lava

November 27, 2024 by Kristina Panos 19 Comments

So now we’ve talked about all kinds of byproducts, including man-made (Fordite), nature-made (fulgurites), and one that’s a little of both (calthemites). Each of these is beautiful in its own way, but I’m not sure about the beauty and merit of corium — that which is created in a nuclear reactor core during a meltdown.

A necklace made to look like corium. Image via OSS-OSS

Corium has the consistency of lava and is made up of many things, including nuclear fuel, the products of fission, control rods, any structural parts of the reactor that were affected, and products of those parts’ reaction with the surrounding air, water, and steam.

If the reactor vessel itself is breached, corium can include molten concrete from the floor underneath. That said, if corium is hot enough, it can melt any concrete it comes in contact with.

So, I had to ask, is there corium jewelry? Not quite. Corium is dangerous and hard to come by. But that doesn’t stop artisans from imitating the substance with other materials.

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Fukushima Daiichi: Cleaning Up After A Nuclear Accident

September 23, 2024 by Maya Posch 47 Comments

On 11 March, 2011, a massive magnitude 9.1 earthquake shook the west coast of Japan, with the epicenter located at a shallow depth of 32 km, a mere 72 km off the coast of Oshika Peninsula, of the Touhoku region. Following this earthquake, an equally massive tsunami made its way towards Japan’s eastern shores, flooding many kilometers inland. Over 20,000 people were killed by the tsunami and earthquake, thousands of whom were dragged into the ocean when the tsunami retreated. This Touhoku earthquake was the most devastating in Japan’s history, both in human and economic cost, but also in the effect it had on one of Japan’s nuclear power plants: the six-unit Fukushima Daiichi plant.

In the subsequent Investigation Commission report by the Japanese Diet, a lack of safety culture at the plant’s owner (TEPCO) was noted, along with significant corruption and poor emergency preparation, all of which resulted in the preventable meltdown of three of the plant’s reactors and a botched evacuation. Although afterwards TEPCO was nationalized, and a new nuclear regulatory body established, this still left Japan with the daunting task of cleaning up the damaged Fukushima Daiichi nuclear plant.

Removal of the damaged fuel rods is the biggest priority, as this will take care of the main radiation hazard. This year TEPCO has begun work on removing the damaged fuel inside the cores, the outcome of which will set the pace for the rest of the clean-up.

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Reviewing Nuclear Accidents: Separating Fact From Fiction

July 22, 2024 by Maya Posch 94 Comments

Few types of accidents speak as much to the imagination as those involving nuclear fission. From the unimaginable horrors of the nuclear bombs on Nagasaki and Hiroshima, to the fever-pitch reporting about the accidents at Three Mile Island, Chernobyl and Fukushima, all of these have resulted in many descriptions and visualizations which are merely imaginative flights of fancy, with no connection to physical reality. Due to radiation being invisible with the naked eye and the interpretation of radiation measurements in popular media generally restricted to the harrowing noise from a Geiger counter, the reality of nuclear power accidents in said media has become diluted and often replaced with half-truths and outright lies that feed strongly into fear, uncertainty, and doubt.

Why is it that people are drawn more to nuclear accidents than a disaster like that at Bhopal? What is it that makes the one nuclear bomb on Hiroshima so much more interesting than the firebombing of Tokyo or the flattening of Dresden? Why do we fear nuclear power more than dam failures and the heavy toll of air pollution? If we honestly look at nuclear accidents, it’s clear that invariably the panic afterwards did more damage than the event itself. One might postulate that this is partially due to the sensationalist vibe created around these events, and largely due to a poorly informed public when it comes to topics like nuclear fission and radiation. A situation which is worsened by harmful government policies pertaining to things like disaster response, often inspired by scientifically discredited theories like the Linear No-Threshold (LNT) model which killed so many in the USSR and Japan.

In light of a likely restart of Unit 1 of the Three Mile Island nuclear plant in the near future, it might behoove us to wonder what we might learn from the world’s worst commercial nuclear power disasters. All from the difficult perspective of a world where ideology and hidden agendas do not play a role, as we ask ourselves whether we really should fear the atom.

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New Robots To Explore New Areas Of Japan’s Fukushima Daiichi Nuclear Plant

January 29, 2024 by Maya Posch 10 Comments

During a press event on January 23rd, Tokyo Electric Power Company (TEPCO) demonstrated two new robots at the mock-up facility at Japan Atomic Energy Agency’s Naraha Center for Remote Control Technology Development (NARREC). As pictured by AP, one is a snake-like robot that should be able to reach very inaccessible areas, while four flying drones will be the first to enter the containment vessel of the Unit 1 reactor for inspection.

These flying drones are 20 cm across, weigh 185 grams each, and were adapted from an existing model that’s used for boiler inspections. At the Naraha Town facility, operators were able to practice flying it into a copy of the Unit 1’s containment vessel via the piping. As the most heavily damaged unit at the Fukushima Daiichi plant, engineers are interested to learn the details of the fuel and debris that has fallen to the bottom of the vessel so that the clean-up and decontamination steps can be planned.

Most of the current work inside the Fukushimi Daiichi reactor buildings is performed by robots, with the TEPCO gallery providing an overview of the wide range of the types used so far.

One of the first was the PackBot, from US-based iRobot, with many more following for a variety of tasks, from inspection to debris clearing and even dry ice-based decontamination.

The Robots Of Fukushima: Going Where No Human Has Gone Before (And Lived)

December 8, 2022 by Ryan Flowers 9 Comments

The idea of sending robots into conditions that humans would not survive is a very old concept. Robots don’t heed oxygen, food, or any other myriad of human requirements. They can also be treated as disposable, and they can also be radiation hardened, and they can physically fit into small spaces. And if you just happen to be the owner of a nuclear power plant that’s had multiple meltdowns, you need robots. A lot of them. And [Asianometry] has provided an excellent synopsis of the Robots of Fukushima in the video below the break.

Starting with robots developed for the Three Mile Island incident and then Chernobyl, [Asianometry] goes into the technology and even the politics behind getting robots on the scene, and the crossover between robots destined for space and war, and those destined for cleaning up after a meltdown.

The video goes further into the challenges of putting a robot into a high radiation environment. Also interesting is the state of readiness, or rather the lack thereof, that prompted further domestic innovation.

Obviously, cleaning up a melted down reactor requires highly specialized robots. What’s more, robots that worked on one reactor didn’t work on others, creating the need for yet more custom built machines. The video discusses each, and even touches on future robots that will be needed to fully decommission the Fukushima facility.

For another look at some of the early robots put to work, check out the post “The Fukushima Robot Diaries” which we published over a decade ago.

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Global Radiation Montoring And Tracking Nuclear Disasters At Home

August 28, 2019 by Lewin Day 10 Comments

Many of us don’t think too much about radiation levels in our area, until a nuclear disaster hits and questions are raised. Radiation monitoring is an important undertaking, both from a public health perspective and as a way to monitor things like weapon development. So why is it done, how is it done, and what role can concerned citizens play in keeping an eye on things?

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The Fukushima Robot Diaries

January 28, 2012 by Jeremy Cook 22 Comments

After the terrible tragedy in Fukushima, the cleanup and damage assessment has begun. A robot operator, known only as [S.H.] has decided to write a blog about their efforts. As pictured above, they are using iRobot models, including the [510 Packbot], and the [710 Warrior].

Since cleanup efforts started, [S.H.] was posting on his or her blog daily. After word of this blog started getting out via various social media outlets, the blog was mysteriously taken down. The blog was at times critical of elements of the cleanup effort, but it’s unknown why the disappearance happened. Efforts to reach [S.H.] were unsuccessfull according to [IEEE].

Fortunately, before the takedown, [IEEE]’s [Erico Guizzo] decided to make a copy of the posts. These have been translated into English and portions are now available at the link listed above. Be sure to check out robot training video after the break. Continue reading “The Fukushima Robot Diaries” →