Tokyo Electric Power Company Holdings (Tepco) said Saturday that an alert system did not work during a test operation held the day prior as part of the restart of the No. 6 reactor at its Kashiwazaki-Kariwa nuclear plant in Niigata Prefecture. The company is working to identify the cause of the problem, but failure to resolve it soon may affect its plan to restart the reactor on Tuesday. According to Tepco, the problem was confirmed at 12:36 p.m., and it stopped the test operation. The alert system is designed to activate when a control rod is being pulled out of the reactor while another rod is already out. The Kashiwazaki-Kariwa reactor would be the first of Tepco's nuclear reactors to be restarted since the March 2011 accident at its tsunami-crippled Fukushima No. 1 nuclear plant.

Fox News Flash top headlines are here. Check out what's clicking on Foxnews.com. A robot that has spent months inside the ruins of a nuclear reactor at the tsunami-hit Fukushima Daiichi plant delivered a tiny sample of melted nuclear fuel on Thursday, in what plant officials said was a step toward beginning the cleanup of hundreds of tons of melted fuel debris. The sample, the size of a grain of rice, was placed into a secure container, marking the end of the mission, according to Tokyo Electric Power Company Holdings, which manages the plant. It is being transported to a glove box for size and weight measurements before being sent to outside laboratories for detailed analyses over the coming months.

A piece of the radioactive fuel left from the meltdown of Japan's tsunami-hit Fukushima Daiichi nuclear power plant has been retrieved from the site using a remote-controlled robot. Investigators used the robot's fishing-rod-like arm to clip and collect a tiny piece of radioactive material from one of the plant's three damaged reactors – the first time such a feat has been achieved. Should it prove suitable for testing, scientists hope the sample will yield information that will help determine how to decommission the plant. The plant's manager, Tokyo Electric Power Company Holdings (Tepco), has said the sample was collected from the surface of a mound of molten debris that sits at the bottom of the Unit 2 reactor's primary containment vessel. The "telesco" robot, with its frontal tongs still holding the sample, returned to its enclosed container for safe storage after workers in full hazmat gear pulled it out of the containment vessel on Saturday.

Fox News Flash top headlines are here. Check out what's clicking on Foxnews.com. An attempt to use an extendable robot to remove a fragment of melted fuel from a wrecked reactor at Japan's tsunami-hit Fukushima Daiichi nuclear power plant was suspended Thursday due to a technical issue. The collection of a tiny sample of the debris inside the 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 where three reactors were destroyed in the March 11, 2011, magnitude 9.0 earthquake and tsunami disaster. The work was stopped when workers noticed that five 1.5-meter (5-foot) 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, the plant operator Tokyo Electric Power Company Holdings said.

Tokyo Electric Power Co. will start a demonstration project as early as Thursday to remove a small amount of radioactive debris from its wrecked nuclear power plant in Fukushima. The operator of the Fukushima No. 1 nuclear power plant, which suffered a meltdown after a massive earthquake and tsunami overwhelmed the facility in 2011, will start the experimental removal process at reactor No. 2 on Thursday, so long as necessary inspections are completed on time, an official from the company said in a news conference Monday. It's a step forward for the utility and the government, which estimates the complete decommissioning of the facility will take three to four decades. Removal of the deadly debris has proved challenging, requiring the development of a robotic arm that can fish out radioactive fuel, metal cladding and other structures in the reactor that melted, cooled and solidified together. Tepco has delayed the start of procedure in the past.

U.S. Ambassador to Japan Rahm Emanuel visited a Fukushima coastal city to support the local fishing industry after China and South Korea raised the alarm over water discharge began from the Fukushima Daiichi nuclear plant. Images taken by miniature drones from deep inside a badly damaged reactor at the Fukushima nuclear plant show displaced control equipment and misshapen materials but leave many questions unanswered, underscoring the daunting task of decommissioning the plant. The 12 photos released by the plant's operator are the first from inside the main structural support called the pedestal in the hardest-hit No. 1 reactor's primary containment vessel, an area directly under the reactor's core. Officials had long hoped to reach the area to examine the core and melted nuclear fuel which dripped there when the plant's cooling systems were damaged by a massive earthquake and tsunami in 2011. Earlier attempts with robots were unable to reach the area.

Eerie new drone footage has for the first time revealed the extent of the damage to the Fukushima nuclear power plant 13 years on from its meltdown. The plant's operators, Tokyo Electric Power Company Holdings, or TEPCO, released 12 photos from inside the site, which are the first ever images from inside the main structural support called the pedestal in the hardest-hit reactor's primary containment vessel, an area directly under the reactor's core. Officials had long hoped to reach the area to examine the core and melted nuclear fuel which dripped there when the plant's cooling systems were damaged by a massive earthquake and tsunami in 2011. The high-definition color images captured by the drones show brown objects with various shapes and sizes dangling from various locations in the pedestal. Parts of the control-rod drive mechanism, which controls the nuclear chain reaction, and other equipment attached to the core were dislodged by the drones. The Fukushima disaster was one of the world's most devastating nuclear mishaps The plant's operators, Tokyo Electric Power Company Holdings, or TEPCO, released 12 photos from inside the site TEPCO officials said they were unable to tell from the images whether the dangling lumps were melted fuel or melted equipment without obtaining other data such as radiation levels.

U.S. Ambassador to Japan Rahm Emanuel visited a Fukushima coastal city to support the local fishing industry after China and South Korea raised the alarm over water discharge began from the Fukushima Daiichi nuclear plant. As Japan prepares to mark the 13th anniversary of its worst-ever nuclear disaster, the man in charge of cleaning it up says his team is fighting to bring a sample out of the heart of the site's radioactive debris. A decades-long project to clean up the remains of the Fukushima Daiichi nuclear power plant is preparing to remove damaged fuel debris from the plant's reactors, but much about what's inside them is still a mystery. The key to unlocking that mystery -- and figuring out how to clean it up -- is a sample of melted fuel from inside a reactor, said Akira Ono, head of decommissioning for Tokyo Electric Power Company Holdings, in an interview with The Associated Press. Getting that sample would be like penetrating "the main keep of the castle" in the battle of decommissioning, Ono said.

Before the 2011 tsunami inundated Ukedo elementary school's classrooms, the ocean was central to the school's identity. In the summer, pupils would run down the 300-metre path to the beach, splitting up into groups to see who could make the best animals out of sand. Every year, students also painted local fishermen's boats, a tradition that resonated strongly in Namie town, where many parents worked in the fishing industry. But when a magnitude 9.0 earthquake, a subsequent tsunami and a nuclear disaster brought devastation to Japan's northeastern Tohoku region, that all changed, Shinichi Sato, a teacher who taught at Ukedo elementary school, told Al Jazeera. "For years after the disaster, we weren't allowed to teach lessons outside, in fear that kids would touch radioactive soil," Sato said.

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.