Fuel Debris Removal Restarts: How Dangerous Is It?

Sep 12, 2024 | News On Japan

TOKYO - The removal of fuel debris, a crucial and highly challenging part of the Fukushima Daiichi Nuclear Power Plant decommissioning process, has resumed. This process, regarded as the most difficult aspect of the decommissioning effort, focuses on extracting melted and solidified nuclear fuel, known as fuel debris, from the plant's reactors.

Professor Takashi Okamoto from the University of Tokyo explained the operation, which took place on September 10 at the No. 2 reactor. Due to the extreme radiation levels inside the containment vessel, the debris can only be removed using robots.

Fuel debris is extremely hazardous due to its high radiation levels, making it impossible for humans to access the area without severe risk. In this operation, robots were deployed alongside human workers, although even the areas where people were present had relatively high radiation levels, complicating the task. The total amount of fuel debris in reactors 1 to 3 is estimated to be about 880 tons, but only a small quantity -- less than 3 grams -- was removed during this phase due to the high radiation risks.

The operation has made significant progress, with the successful insertion of the equipment into the containment vessel marking a major step forward. Tokyo Electric Power Company (TEPCO) considers this the first phase of the operation, an important milestone in the long and complex process of fuel debris removal. According to Professor Okamoto, the removal of debris is challenging because it must be done entirely by robots, given the hazardous nature of the material and the inability of humans to approach it.

There are no concerns about radioactive contamination or a potential recriticality during the operation, as the amount being removed is very small. Even if the process fails, there would be no environmental impact, and the task could be redone. The extracted fuel debris will be analyzed at a research facility in Ibaraki Prefecture to study its crystal structure, which will help develop future strategies for more extensive debris removal.

While there are 880 tons of fuel debris remaining, Professor Okamoto expressed cautious optimism that once they understand the condition of the material inside, it may be possible to remove the rest within a reasonable timeframe. The overall goal is to complete the decommissioning by 2051, with the removal and safe storage of the debris as the top priority.

Source: FNN

Record Rain Triggers Level 5 Warning in Fukui

Record rainfall caused 19 rivers to overflow across Fukui Prefecture, flooding roads and homes, triggering landslides and temporarily forcing authorities to issue the highest-level heavy rain emergency warning from early Sunday morning.

Drones Deliver Supplies to Residents Cut Off by Landslide

Drones were used to deliver food and daily necessities to an isolated mountain community in Himi City, Toyama Prefecture, on August 30 after torrential rain triggered a landslide that cut off road access, while volunteers continued flood recovery work in neighboring Ishikawa Prefecture.

Typhoon No. 23 Overtakes No. 22 East of Japan as Both Head North

Two typhoons east of Japan were moving northward on August 30, with Typhoon No. 23 (Banlan) overtaking Typhoon No. 22 (Artau), although neither storm is expected to have a direct impact on Japan.

Nine-Minute Drone Video Shows Scale of Aeon Mall Damage

A 9-minute, 13-second drone video filmed inside Aeon Mall Kumamoto two days after the deadly explosion has provided a detailed view of the destruction, showing collapsed ceilings, heavy dust and widespread damage that may have affected between one-third and nearly half of the shopping center.

Conditions Ease as Typhoon No. 18 Passes Okinawa

Strong Typhoon No. 18 was moving northwest through the East China Sea on the night of August 26, gradually pulling away from Okinawa and the Amami Islands as lingering rain, strong winds and high waves were expected to ease. As of 9 p.m. on August 26, the typhoon was over waters north-northwest of Kume Island and moving northwest.

MEDIA CHANNELS

MORE Sci-Tech NEWS

Eight Kinki Fault Zones Ranked at Highest Alert Level for Major Earthquakes

The Japanese government has revised its assessment of active faults across the Kinki region for the first time in about 20 years, increasing the number of fault zones considered at the highest level of concern for earthquakes of magnitude 6.8 or greater from three to eight.

Osaka Residents Voice Fears Over Massive Data Center

Residents in Minoh, Osaka Prefecture, have asked the city to take a more active role in explaining and reviewing plans for a large data center to be built on the former site of Osaka University's Minoh Campus, citing concerns over low-frequency noise, loss of sunlight and other potential effects on daily life.

Strong Magnitude 5.9 Earthquake Shakes Tokyo

A magnitude 5.9 earthquake centered in southern Ibaraki Prefecture shook a wide area of the Kanto region at around 2 a.m. on August 23, registering a maximum intensity of lower 5 on Japan's seven-level seismic scale in parts of Ibaraki, Saitama, Chiba and Tokyo.

Aphantasia May Affect About 4% of Japanese

A cognitive trait known as aphantasia, in which people are unable to voluntarily form images in their minds despite knowing what objects look like, may affect about 4% of people, highlighting significant differences in how individuals experience memory, imagination and everyday tasks.

Drought Deepens Across Japan

Dangerous heat returned across Japan on August 19, complicating disaster recovery efforts in earthquake-hit Kumamoto and flood-damaged Chiba while unusually low rainfall and limited snowfall pushed reservoirs in several regions toward critical levels.

A Closer Look at Lithium-Air Batteries

Japanese researchers are developing a lithium-air battery that uses oxygen from the atmosphere to store and generate electricity, promising nearly five times the capacity of conventional lithium-ion batteries at less than half the weight and potentially opening the way to far longer electric vehicle driving ranges.

Footage Shows Fault Tearing Up Rice Paddy in Kumamoto

Security camera footage captured the moment part of the Hinagu Fault Zone broke through the ground during the Kumamoto earthquake on July 28, as strong shaking lifted the surface of a rice field and moved a nearby light truck violently.

T. Rex May Have Lived to 40, New Research Suggests

New research is reshaping long-held assumptions about Tyrannosaurus rex, including suggestions that the giant predator may have lived to around 40 years rather than 28, while advances in fossil analysis are also offering new clues about dinosaur growth, posture and even color.

< 2 3 4 5 >