It will take six months to a year to analyze a tiny sample of radioactive debris retrieved by a robot from Tokyo Electric Power Company Holdings' crippled Fukushima No. 1 nuclear plant, its operator said Thursday. The analysis could shed light on radioactivity levels and the chemical structure of the fuel debris -- a key part of preparation for the decadeslong decommissioning process. Around 880 tons of hazardous material remain at the Fukushima plant, more than 13 years after a tsunami caused by an earthquake triggered one of the world's worst nuclear incidents. Last week, the sample, weighing just below 0.7 gram -- equivalent to about one raisin -- was delivered to a research lab near Tokyo for analysis. It had been removed from a reactor by an extendible robotic device in a tricky operation suspended several times by technical problems.

Tokyo Electric Power Company Holdings Inc. halted its investigation of the inside of the containment vessel of the No. 1 reactor at its stricken Fukushima No. 1 nuclear power plant on Wednesday. The move came after an issue was found during preparation work for the display of data such as radiation levels from dosimeters inside underwater robots to be used in the survey. The preparations began at noon the same day and were halted around two hours later. Tepco said that it will resume the survey once measures to resolve the issue are taken. In the survey, which will continue until around August, Tepco aims to take pictures of melted nuclear fuel debris and other deposits using six types of underwater robots to record their locations and thickness in water that has accumulated at the bottom of the containment vessel.

Fukushima – A robot created by a team from a technology college in northeastern Japan recently won the top prize in a robotics competition that had the theme of decommissioning the Fukushima No. 1 nuclear power plant. The Mehikari robot of Fukushima College earned praise for its speed as well as ability to employ different methods to retrieve mock debris similar in size to that at the plant, the site of a nuclear disaster triggered by a massive earthquake and tsunami on March 11, 2011. The robot completed the set task in about 2 minutes, the fastest time, in the annual competition aimed at fostering future engineers that was attended by students from 13 colleges belonging to the National Institute of Technology. Sunday's competition was the fifth of its kind. Students in 14 teams from the colleges across the country such as in Osaka and Kumamoto prefectures were tasked this year with developing robots to remove fuel debris from the plant, organizers said.

Nearly a decade after the three meltdowns at Fukushima No. 1 nuclear power plant, plans are underway to finally remove nuclear fuel debris from the three reactors. But in order to remove it, Tokyo Electric Power Company Holdings Inc. (Tepco), the operator of the plant, needs to ensure there is a place to store the debris once it is retrieved. This is thought to be the reason why the government is rushing to give the green light to releasing tritium-laced water piling up at the plant into the Pacific -- to give room for the storage of fuel debris. But removing the fuel debris -- a crucial step in the decommissioning process -- is an enormous task on its own, with measures that need to be resolved emerging one after another. At a three-day online meeting of the Atomic Energy Society of Japan from Sept. 16, an official from the International Research Institute for Nuclear Decommissioning (IRID) who is in charge of technical development regarding the decommissioning of the Fukushima plant, explained the plan, or the lack thereof, to remove the debris at reactor No. 2. "We will consider what kind of measures to take, comparing tactics and developing techniques," the official said, with a hint of frustration at not being able to come up with a specific way yet.

A plan to remove fuel debris from the primary containment vessel of a reactor at the Fukushima No. 1 nuclear power plant is expected to be further pushed back after it became apparent that Tokyo Electric Power Company Holdings Ltd. will not be able to conduct an internal probe -- a key step to start removing the fuel debris -- by the end of March as planned. The internal probe would involve using remote-controlled robots to collect fuel debris inside the No. 1 reactor so Tepco can examine its composition and form. Tepco's plan is to open three holes in both the outer and inner doors of the primary containment vessel using pressurized water mixed with a polishing agent. After it succeeded in opening three holes in the outer door, Tepco started drilling a hole in the inner door in June 2019. But that procedure caused the concentration of radioactive dust to increase temporarily, prompting staff to suspend work.

YOKOHAMA - Toshiba Corp. unveiled a remote-controlled robot with tongs on Monday that it hopes will be able to probe the inside of one of the three damaged reactors at Japan's tsunami-hit Fukushima nuclear plant and grip chunks of highly radioactive melted fuel. The device is designed to slide down an extendable 11-meter (36-foot) long pipe and touch melted fuel inside reactor 2's primary containment vessel. The reactor was built by Toshiba and GE. An earlier probe carrying a camera captured images of pieces of melted fuel in the reactor last year, and robotic probes in the two other reactors have detected traces of damaged fuel, but the exact location, contents and other details remain largely unknown. Toshiba's energy systems unit said experiments with the new probe planned in February are key to determining the proper equipment and technologies needed to remove the fuel debris, the most challenging part of the decommissioning process expected to take decades.

An underwater robot deployed into one of Fukushima's defunct nuclear reactors discovered what appeared to be hunks of melted fuel debris. Video recorded by the robot showed "lava-like" lumps inside the submerged No. 3 reactor. The robot was sent into the reactor through a pipe meant to prevent the escape of radioactive gas, Reuters reported Thursday. Operators aimed for the machine to locate radioactive melted fuel rods in order to remove them and continue decommissioning the plant. Discovering the melted fuel would mark a major accomplishment for plant's cleanup process.

Images captured by an underwater robot on Saturday showed massive deposits believed to be melted nuclear fuel covering the floor of a damaged reactor at Japan's destroyed Fukushima nuclear plant. The robot found large amounts of solidified lava-like rocks and lumps in layers as thick as 1m on the bottom inside a main structure called the pedestal that sits underneath the core inside the primary containment vessel of Fukushima's Unit 3 reactor, said the plant's operator, Tokyo Electric Power Co. On Friday, the robot spotted suspected debris of melted fuel for the first time since the 2011 earthquake and tsunami caused multiple meltdowns and destroyed the plant. The three-day investigation of Unit 3 ended on Saturday. Locating and analysing the fuel debris and damage in each of the plant's three wrecked reactors is crucial for decommissioning the plant. The search for melted fuel in the two other reactors has so far been unsuccessful because of damage and extremely high radiation levels.

TOKYO – Images captured by an underwater robot showed massive deposits believed to be melted nuclear fuel covering the floor of a damaged reactor at Japan's crippled Fukushima nuclear plant. The robot found large amounts of solidified lava-like rocks and lumps in layers as thick as 3 feet on the bottom inside of a main structure called the pedestal that sits underneath the core inside the primary containment vessel of Fukushima's Unit 3 reactor, said the plant's operator, Tokyo Electric Power Co. On Friday, the robot spotted suspected debris of melted fuel for the first time since the 2011 earthquake and tsunami caused multiple meltdowns and destroyed the plant. The three-day probe of Unit 3 ended Saturday. Locating and analyzing the fuel debris and damage in each of the plant's three wrecked reactors is crucial for decommissioning the plant. The search for melted fuel in the two other reactors has so far been unsuccessful because of damage and extremely high radiation levels.

More than six years after the core meltdowns triggered by March 2011 mega-quake and tsunami, Tokyo Electric said Saturday that the robot probing reactor 3 at the defunct Fukushima No. 1 power plant had likely spotted fuel debris for the first time at the bottom of its primary containment vessel. Some of the debris looks like rocks and sand, and was accompanied by scaffolding and other objects from the reactor that had formed a pile about a meter high. On Friday, Tokyo Electric Power Company Holdings Inc. announced that the same robot had found what appeared to be melted fuel at the bottom of the pressure vessel, which holds the core. On Saturday, images released by the utility showed black, lava-like objects discovered by the so-called mini sunfish robot. "It's natural to assume that the debris melted and dropped," said a Tepco official who briefed reporters.