22 Octobre 2014
October 22, 2014
THE ASAHI SHIMBUN
The operator of the crippled Fukushima No. 1 nuclear power plant started dismantling a canopy on Oct. 22 installed over the damaged No. 1 reactor building to prevent radioactive substances from entering the atmosphere.
Workers at the Tokyo Electric Power Co. plant started the operation shortly after 7 a.m. They used a crane-mounted drill to make eight 30-square-centimeter holes in one of the canopy's six massive panels.
After drilling into the 40-meter-by-7-meter panel, the workers sprayed synthetic, anti-scattering resin inside the building to minimize the possibility of radioactive substances being stirred up into the air. Cameras will also be inserted into the building to survey the vast amount of debris inside.
The structure's walls and roof were severely damaged in a hydrogen explosion on March 12, 2011, after the plant was struck by the Great East Japan Earthquake and tsunami. The cover was erected in October 2011.
After dismantling the canopy, TEPCO plans to remove a large amount of the highly contaminated debris, rubble and dust that remain inside in fiscal 2016 and spent nuclear fuel rods stored in pools in fiscal 2017.
The canopy-removal operation will go into full swing after March 2015, as TEPCO is currently placing priority on the construction of frozen soil walls near the No. 1 reactor building to prevent groundwater from seeping in.
During work to clear debris from the plant's No. 3 reactor building in August 2013, radioactive substances spread and contaminated plant workers on site about 500 meters away.
To obtain consent from local governments for the project, the utility promised to closely monitor radiation levels during the canopy-removal work and provide them with such data.
TOKYO (Kyodo) -- The operator of the crippled Fukushima Daiichi nuclear plant began preparatory work to dismantle the No. 1 reactor building's cover Wednesday as a first step toward removing melted fuel.
The cover shrouding the building, damaged by a hydrogen explosion in the 2011 nuclear crisis, was installed following the accident to keep radioactive materials from dispersing.
Tokyo Electric Power Co. plans to finish removing the cover around March 2016. It will then aim to begin cleaning up the debris from the hydrogen explosion and removing spent fuel stored in a pool in the building by the end of March 2018.
TEPCO said the work of removing the melted fuel inside the crippled reactor would begin in 2020 at the earliest, but said it has yet to gain a detailed grasp of the situation inside the reactor and consider the specifics of how the fuel is to be extracted.
On Wednesday morning, TEPCO started making holes in the roof of the building cover in order to insert antidispersal agents to prevent radioactive dust from being scattered. The actual dismantling of the cover will start in March 2015, the utility said.
TEPCO had initially sought to begin preparations to dismantle the building cover by last March, but the plan was delayed due to equipment failure. The plan was delayed again after local residents voiced concern that the company's debris cleanup work at the Fukushima plant may have contaminated rice crops in nearby areas.
October 22, 2014(Mainichi Japan)
See also :
Tepco began preparatory work on Wednesday to dismantle the cover on the reactor 1 building at the crippled Fukushima No. 1 nuclear plant, as a step toward eventually removing the melted fuel inside. […]