Tokyo, March 6 (Jiji Press)–A decade after Japan’s worst nuclear accident, the country still has a long way toward dismantling crippled nuclear reactors at Tokyo Electric Power Company Holdings Inc.’s <9501> Fukushima No. 1 power plant.
The pace of radioactive water occurrence at the plant has been curbed, while nuclear fuel debris in the damaged reactors has been left almost untouched.
According to the current work schedule, it will take 20 to 30 more years to complete the decommissioning of the crippled reactors.
At the Fukushima No. 1 plant, radioactive water continues to come up, through groundwater and rainwater inflows into reactor buildings, in addition to the use of water to cool the fuel debris.
However, as a result of measures including pumping up groundwater from wells near the reactor buildings and creating underground frozen-soil walls around the buildings, the daily amount of water being newly contaminated with radioactive materials dropped from 540 tons in May 2014 to 140 tons in 2020.
The work environment at the Fukushima plant also improved over the last decade. Full-face masks and protective suits were initially required all over the plant site, but only light gear is needed in 96 pct of the plant site now, following the removal of contaminated surface soil and other efforts.
The removal of nuclear fuel from fuel pools has been finished at the No. 4 reactor building in December 2014 and at the meltdown-hit No. 3 building last month.
Meanwhile, more than 1,000 tanks have been set up within the Fukushima plant site to store radioactive water after purification processing. As of last month, such processed water amounted to 1.24 million tons.
Toward the removal of nuclear fuel debris, TEPCO has taken images of fuel debris in the No. 2 and No. 3 reactors. In February 2019, the plant operator confirmed that the debris in the No. 2 reactor can be moved with a research device.
Due to high levels of radiation, however, there are many details left unknown about the fuel debris.
Furthermore, the project to develop a machine to remove the fuel debris has been postponed, due to the coronavirus pandemic.
The Fukushima reactors remain unstable 10 years after the nuclear accident. In the wake of a strong earthquake off Fukushima Prefecture on Feb. 13, the water levels inside the No. 1 and No. 2 reactors’ containment vessels fell, suggesting that damage to the reactors may have expanded.