The operator of the crippled Fukushima No. 1 nuclear plant is planning to survey melted fuel debris at the No. 2 reactor by the end of March -- using a special device -- in an operation it hopes will help it determine the best method for its removal, sources said Wednesday. It will be the first survey by Tokyo Electric Power Company Holdings Inc. involving direct contact with the debris at the Nos. 1 to 3 units, which suffered core meltdowns triggered by the March 2011 earthquake and tsunami. Tepco is considering extracting debris -- the most difficult part of the decommissioning process -- first from the No. 2 unit. Gravel-like fuel material was confirmed at the bottom of its containment vessel in a January survey using a telescopic arm. The utility aims to collect information in the survey to help determine how to extract the debris and develop a container in which to keep it.
The operator of the disaster-hit Fukushima No. 1 nuclear power plant said Wednesday it has completed its first attempt to use a remote-controlled probe to manipulate melted fuel accumulating at the bottom of one of the crippled reactors. During the nearly eight-hour operation, Tokyo Electric Power Company Holdings Inc. inserted the probe that is equipped with a camera, radiation meter and tong-like grips into the primary containment vessel of the No. 2 reactor. Of the six locations that were surveyed, the probe, which is 30 centimeters tall and 10 cm wide, successfully lifted several centimeters of deposits at five locations, a TEPCO official said at a news conference. But in the remaining area that resembled clay, the probe could not pick up any of the deposited material, indicating it was relatively solid. The findings from the operation will provide important information to help in the decommissioning of the Nos. 1 to 3 reactors at the plant that suffered core meltdowns in the nuclear crisis that began in March 2011, according to Tepco.
The latest robot attempting to find the 600 tons of nuclear fuel and debris that melted down six year ago in the wrecked Fukushima No. 1 nuclear power plant met its end in less than a day. The scorpion-shape machine, built by Toshiba Corp., entered the No. 2 reactor core Thursday and stopped 3 meters (10 feet) short of a grate that would have provided a view of where fuel residue is suspected to have gathered. Two previous robots aborted similar missions after one got stuck in a gap and another was abandoned after finding no fuel during six days of searching. After spending most of the time since the 2011 disaster containing radiation and limiting ground water contamination, scientists still don't have all the information they need for a cleanup that the government estimates will take four decades and cost ¥8 trillion. It is not yet known if the fuel melted into or through the containment vessel's concrete floor, and determining the fuel's radioactivity and location is crucial to inventing the technology needed to remove it.
The operator of the disaster-struck Fukushima No. 1 nuclear power plant said Thursday it will attempt to examine the inside of reactor 1 next Tuesday using a remote-controlled robot. The move follows a botched attempt by another self-propelled robot to take a look inside reactor 2, which had also sustained a meltdown after the March 11, 2011, Great East Japan Earthquake and tsunami. That robot became unable to move when it encountered debris and eventually could not be retrieved. These are the first attempts by Tokyo Electric Power Co. Holdings Inc. to examine the insides of the wrecked reactors since the nuclear disaster started. For the reactor 1 inspection, Tepco said the new robot will carry out a four-day probe inside the containment vessel.