2021 December 10 « nuclear-news

Upcoming Inspection of Fukushima Unit 1

November 25, 2021

TEPCO announced that the next phase of containment inspections inside unit 1 will finally take place in early 2022. This next phase of inspections had been delayed due to technical challenges, concerns of radioactive dust releases, then due to the pandemic.

Some of the explanatory materials provide new insight into the true situation inside unit 1. It has been speculated since 2011 that melted fuel (aka corium) flowed out of the pedestal of unit 1, across the containment floor, and burned through the thin connection edge of the containment structure. Diagrams included in this most recent report show that the entities tasked with decommissioning the damaged reactors think so too. Diagrams originally from NDF, the decommissioning authority, and IRID, the main agency tasked with research, show the same.

The graphic below shows a significant pile of melted fuel in the pedestal and along the outer edge of the containment structure. The right side graphic shows melted fuel a significant way up to the lower edge of the downcomer tubes that route into the torus tube. Evidence of fuel debris inside the torus tube was found in earlier inspections along with our early findings that appeared to show fuel debris under the water in the torus room outside of containment.

This side view of the same area shows what IRID and TEPCO assume to be the situation inside unit 1’s containment as they prepare for the upcoming inspections.The red color is solidified previously melted fuel, The brown layer is the sediment layer and the blue layer is standing water inside containment. The sediment layer on the right side where inspections have already taken place is significantly lower than the sediment bed directly adjacent to the assumed location of the fuel debris. The depth difference appears to be 3 times as much adjacent to the melted fuel locations.

The debris bed on the shallow right side was roughly 4-10 inches deep based on TEPCO estimates in 2017. If the left side adjacent to the solidified fuel is 3 times the depth, it would be 12-30 inches in depth. What exactly this debris bed is and how it developed had caused head-scratching for years. A TEPCO report in 2017 showed it contained stainless steel, materials related to shielding, cabling, and some low levels of reactor-based radioactive isotopes. If this material contained additional substances or not was a bit ambiguous. There had been some initial assumptions this was pulverized concrete. There may have been some involvement of the concrete structures into this debris pile through mechanical destruction or molten corium concrete interaction, but TEPCO provides insufficient data to confirm or rule this out.

Another 2017 report gave some rough estimates of the depth of the known parts of the debris bed. The known parts from an earlier set of inspections would be the general area marked by the A in the above graphic. This area is roughly 4 – 10 inches in depth. The left side adjacent to the solidified fuel would then be about 12 – 30 inches in depth. The deposits closer to the pedestal opening were close to 1 meter deep on a 2017 inspection. TEPCO could not determine if there was any solidified fuel beneath. They assumed the debris bed was providing extensive shielding that would prevent the detection of any layer of solidified fuel. This debris bed appears to reside 1/3 of the way up the downcomer cover. It is likely some amount of it has entered the torus tube and potentially the torus room.

Upcoming Inspections:
The upcoming inspections include a total of 6 ROV units. The remote operational vehicles are not true robots as each one has a control tether. The biggest concern with these units is having one become stranded, preventing the introduction of future ROV units to continue inspections. Each ROV unit has an assigned task. Due to internal equipment inside containment, a series of rings will be placed by the first ROV to help guide the ROV units and prevent entanglement.

ROV-A

ROV-A will attempt to traverse the south direction to the pedestal doorway.

ROV-A2 will attempt to enter the pedestal to capture imagery of the conditions and potential fuel location.

ROV units B to E each have similar tasks tied to characterizing the fuel debris and sediments.
Each ROV has about an 80-hour high radiation tolerance. They will be introduced by the level of risk with ROV-A2 going into the pedestal last due to the high risk. Preparation work begins in January. The entire series of inspections are currently scheduled to take 10 months to complete.

December 10, 2021 Posted by dunrenard | Fukushima 2021 | Fukushima Daiichi, Inspection, Unit 1 | Leave a comment

Japan’s Upcoming Nuclear Waste Dump

The last known “deliberate nuclear waste dumping into the ocean,” outside of the “good graces” of what the industry refers to as “detailed environmental impact assessments” that somehow (questionably, mysteriously, are you kidding me!) seem to justify dumping toxic nuclear waste was October 1993 when the Russian navy illegally dumped 900 tons of nuclear waste into international waters off the coast of Vladivostok near Japan and Korea. Moscow claimed they were running out of storage space and that “radioactive waste is not hazardous and the dumping would be according to international norms.” Sound familiar?

In 1993 Japan called the Russian dumping “extremely regrettable.”

December 7, 2021 by Robert Hunziker

Nuclear waste is an interminable curse that eternally haunts the future of civilization for hundreds/thousands of years.

“The challenge of making nuclear power safer doesn’t end after the power has been generated. Nuclear fuel remains dangerously radioactive for thousands of years after it is no longer useful in a commercial reactor.” (Source: Nuclear Waste, Union of Concerned Scientists, April 22, 2016)

There are 440 nuclear power plants in the world, all of which use nuclear fission, prompting one simple question: Is the process of generating heat via nuclear fission with a byproduct of extremely toxic radioactive waste lasting hundreds, or more, years for purposes of simply “boiling water” the epitome of human stupidity?

In April 2021, the Japanese government announced its decision to discharge nuclear waste from Fukushima Daiichi Power Plant into the Pacific Ocean via a sub-seabed pipeline. At least 1.2 million tons of tritium-laced toxic water will be discharged.

As it happens, nuclear powers of the world regularly dump nuclear waste into the ocean in violation of the London Convention (1972) and the London Protocol (1996), which are the two principal international agreements against dumping nuclear waste into the oceans. But, they get around the rules by dumping under the cover of “detailed environmental impact assessments.”

In 1993 Japan called the Russian dumping “extremely regrettable.” Yet, at the time, Tokyo Electric Power Company was itself discharging radioactivity into the ocean. At the time, Japanese power stations were allowed to dump nuclear waste into the ocean based upon “detailed environmental impact assessments.” (OMG is this real?) (Source: Nuclear Dumping at Sea Goads Japan Into Action, NewScientist, November 6, 1993)

“Jinzaburo Takagi, a physicist working with the Citizens’ Nuclear Information Centre in Tokyo, says: ‘If the Russians had done an impact assessment for their dumping, it would have proved safer than the Japanese power plants.’ He says local authorities in Japan have measured elevated levels of radionuclides in shellfish and seaweed near the nuclear plants. If the Japanese criticize Russian dumping, says Takagi, ‘then they will have to abandon the option of dumping nuclear waste,” Ibid.

The abovementioned series of conflicting events surrounding disposal of nuclear waste brings to mind the complexity and hypocrisy that runs throughout the nuclear industry. It stems from the hideous fact that the industry does not know what to do with radioactive waste, which is the most toxic material on the face of the planet; they do make up weird excuses and protocols to actually dump the toxic material into international waters. Not only that, but, as mentioned in the quoted article above, “local authorities in Japan have measured elevated levels of radionuclides in shellfish and seaweed near the nuclear plants.” That’s a prime example of human insanity at work. And, that was 30 years ago, but it’s a safe bet that it’s the same today.

The bitter truth is that the citizens of the world are stuck with nuclear power and its offbeat craziness and its horrific potential destructiveness because the major powers have it and want to keep it.

Greenpeace has experts with “boots-on-the-ground” at Fukushima since the beginning. Here’s Greenpeace’s take on the situation, as of recent: “There are many technical and radiological reasons to be opposed to discharging Fukushima waste water into the Pacific Ocean. And Greenpeace East Asia has reported on these and continues to investigate. But the decision also affects you on a fundamental level. It should rightly trigger an outrage. In the 21^st century, when the world’s oceans are already under the most severe threats including the climate and biodiversity emergencies, a decision by any government to deliberately contaminate the Pacific with radioactivity because it’s the least cost/cheapest option when there are clear alternatives seems so perverse. That it is Japan, given its historical role in securing the prohibition on nuclear dumping in the London Convention and London Protocol, makes it all the more tragic.” (Shaun Burnie, The Japanese Government and the Fukushima Nuclear Disaster – History Repeating Itself? Greenpeace, November 17, 2021)

Further to the point of the future impact of dumping toxic radioactive water from TEPCO’s storage water tanks into the Pacific Ocean: Tsinghua University analyzed the diffusion process of the treated Fukushima contaminated water to be discharged into the ocean from 2023 onward. The results show that the tritium, which is the main pollutant, will spread to the whole of the North Pacific in 1200 days. (Source: Tracking Contaminated Water From The Fukushima Nuclear Accident, Phys.org, December 2, 2021)

The Tsinghua University analysis went on to discuss the risks, stating: “Large amounts of radionuclides can affect marine biological chains and adversely influence marine fisheries and human health. The global effects of Fukushima discharge, which will last 30 to 40 years, remain unknown.”

As stated by Tsinghua, the pollutants will reach as far as the coast of North America to the east and as far as Australia to the south. Eventually, the South Pacific Ocean and the Indian Ocean (2400 days) will be affected. On day 3600 the pollutants will cover almost the entire Pacific Ocean.

According to a UN news release d/d April 2021: “Three independent UN human rights experts expressed deep regret on Thursday over Japan’s decision to discharge potentially still radioactive Fukushima nuclear plant water into the ocean, warning that it could impact millions across the Pacific region.”

The experts call the decision by Japan “very concerning,”

Moreover, according to the UN: “While Japan said that the tritium levels are very low and do not pose a threat to human health, scientists warn that in the water, the isotope organically binds to other molecules, moving up the food chain affecting plants and fish and humans.”

“Moreover, they say the radioactive hazards of tritium have been underestimated and could pose risks to humans and the environment for over 100 years.”

Source: Counterpunch