An attempt to use an extendable robot to remove a fragment of melted fuel from a wrecked reactor at Japan’s tsunami-hit Fukushima Dai-ichi nuclear power plant was suspended yesterday due to a technical issue.
The collection of a tiny sample of the debris inside Unit 2 reactor’s primary containment vessel would start the fuel debris removal phase, the most challenging part of the decades-long decommissioning of the plant, at which three reactors were destroyed after a tsunami hit the site following an earthquake measuring 9.0 on the Richter scale on March 11, 2011.
The work was stopped when workers noticed that five 1.5m pipes used to maneuver the robot were placed in the wrong order and could not be corrected within the time limit for their radiation exposure, said Tokyo Electric Power Co Holdings (TEPCO), the plant’s operator.
Photo curtesy of TEPCO via AP
The pipes were to be used to push the robot inside and pull it back out when it finished. Once inside the vessel, the robot is operated remotely from a safer location.
The robot can extend up to about 22m to reach its target area to collect a fragment from the surface of the melted fuel mound using a device equipped with tongs that hang from the tip of the robot.
The mission to obtain the fragment and return with it is to last two weeks.
A new start date had not been decided, TEPCO said.
TEPCO president Tomoaki Kobayakawa said the priority was safety rather than rushing the process and that he planned to investigate the cause of the pipe setup problem.
“I understand that the decision was to stop and not push when there was a concern,” Kobayakawa told reporters in Niigata Prefecture, where he visited to discuss another TEPCO-operated nuclear power plant with the local community.
The sample-return mission is the first crucial step of a decades-long decommissioning at the Fukushima Dai-ichi site.
However, its goal to bring back less than 3g of an estimated 880 tonnes of radioactive molten fuel underscores the daunting challenges.
Despite the small amount of the debris sample, it would provide key data to develop decommissioning methods and necessary technology and robots, experts say.
Better understanding of the melted fuel debris is key to decommissioning the three wrecked reactors and the entire plant.
The Japanese government and TEPCO are sticking to a 30-to-40-year cleanup target set soon after the meltdown, despite criticism that it is unrealistic. No specific plans for the full removal of the melted fuel debris or its storage have been decided.
Drug lord Jose Adolfo Macias Villamar, alias “Fito,” was Ecuador’s most-wanted fugitive before his arrest on Wednesday, more than a year after he escaped prison from where he commanded the country’s leading criminal gang. The former taxi driver turned crime boss became the prime target of law enforcement early last year after escaping from a prison in the southwestern port of Guayaquil. Ecuadoran President Daniel Noboa’s government released “wanted” posters with images of his face and offered US$1 million for information leading to his capture. In a country plagued by crime, members of Fito’s gang, Los Choneros, have responded with violence, using car
Two former Chilean ministers are among four candidates competing this weekend for the presidential nomination of the left ahead of November elections dominated by rising levels of violent crime. More than 15 million voters are eligible to choose today between former minister of labor Jeannette Jara, former minister of the interior Carolina Toha and two members of parliament, Gonzalo Winter and Jaime Mulet, to represent the left against a resurgent right. The primary is open to members of the parties within Chilean President Gabriel Boric’s ruling left-wing coalition and other voters who are not affiliated with specific parties. A recent poll by the
TENSIONS HIGH: For more than half a year, students have organized protests around the country, while the Serbian presaident said they are part of a foreign plot About 140,000 protesters rallied in Belgrade, the largest turnout over the past few months, as student-led demonstrations mount pressure on the populist government to call early elections. The rally was one of the largest in more than half a year student-led actions, which began in November last year after the roof of a train station collapsed in the northern city of Novi Sad, killing 16 people — a tragedy widely blamed on entrenched corruption. On Saturday, a sea of protesters filled Belgrade’s largest square and poured into several surrounding streets. The independent protest monitor Archive of Public Gatherings estimated the
Irish-language rap group Kneecap on Saturday gave an impassioned performance for tens of thousands of fans at the Glastonbury Festival despite criticism by British politicians and a terror charge for one of the trio. Liam Og O hAnnaidh, who performs under the stage name Mo Chara, has been charged under the UK’s Terrorism Act with supporting a proscribed organization for allegedly waving a Hezbollah flag at a concert in London in November last year. The rapper, who was charged under the anglicized version of his name, Liam O’Hanna, is on unconditional bail before a further court hearing in August. “Glastonbury,
RSS