Nearly a thousand storage tanks are scattered across the Fukushima No. 1 nuclear power plant, holding a staggering 1.1 million tons of treated water used to keep its melted reactor cores cool while they rust in the sun. Plant manager Tokyo Electric Power Company Holdings Inc., or Tepco, plans to build more of the gigantic tanks to hold another 0.27 million tons, which is roughly the equivalent of 108 Olympic-size swimming pools. The new tanks are expected reach full capacity in four or five years. Each tank takes seven to 10 days to fill and holds between 1,000 to 1,200 tons of liquid, Tepco officials told reporters during a tour in February organized by the Japan National Press Club. It's been eight years since Fukushima No. 1 suffered three core meltdowns triggered by tsunami following the Great East Japan Earthquake, but the situation with the tanks may be a sign Tepco has yet to get the facility under control.
The location and condition of the fuel in the three reactors hit by core meltdowns is critical information for Tokyo Electric Power Company Holdings Inc., which runs the plant. Removing the fuel debris is considered the most difficult part of decommissioning the complex. Unit 3 has the highest level of water inside at 6 meters. The fuel debris inside is presumed to have melted through its pressure vessel and settled at the bottom of its primary containment vessel. "Until today, no one has seen the situation inside reactor 3," said Tsutomu Takeuchi, senior manager at Toshiba's Fukushima Restoration and Fuel Cycle Project Engineering Department.
Six years after the triple meltdown at the Fukushima No. 1 nuclear power plant, recent investigations underneath the damaged reactor 2 using cameras and robots came close to identifying melted fuel rods for the first time. Experts say getting a peek inside the containment vessel of reactor 2 was an accomplishment. But it also highlighted how tough it will be to further pinpoint the exact location of the melted fuel, let alone remove it some time in the future. The biggest hurdle is the extremely lethal levels of radiation inside the containment vessel that not only prevent humans from getting near but have also crippled robots and other mechanical devices. Safely removing the melted fuel would be a best-case scenario but the risks and costs should be weighed against the option of leaving the melted fuel in the crippled reactors, some experts said.
The economy and industry ministry on Monday proposed a revision to its decades-long road map to clean up the radioactive mess at the Fukushima No. 1 nuclear power plant, which was wrecked by a massive earthquake and tsunami in 2011. Nearly nine years after the accident, the decommissioning of the plant, where three reactors melted, remains largely an uncertainty. The revised road map, to be formally approved later this month, lacks details on how the complex should look at the end but maintains a 30- to 40-year target to finish. Here is a look at some of the challenges in decommissioning the Fukushima No. 1 plant: By far the toughest challenge is removing the 800 tons of nuclear fuel in the three reactors that melted, fell from the cores and hardened at the bottom of their primary containment vessels. Over the past two years, plant operator Tokyo Electric Power Company Holdings Inc., known as Tepco, has made progress in gathering details mainly from two of the three reactors.