The first wall panel has been removed from the temporary cover over the damaged reactor building at unit 1 of the Fukushima Daiichi NPP in Japan. Tokyo Electric Power Company (Tepco) said on 13 September that there were "no significant changes observed at the dust monitors, which check the concentrations of radioactive materials and the monitoring posts installed along the site boundary".

Removal of the cover – installed in October 2011 to prevent the dispersal of radioactive materials – began in July 2015. The work, which is scheduled for completion by year-end – will enable rubble to be taken from the top of the reactor building in preparation for the extraction of fuel from the unit's used fuel pool.

Tepco said the dismantling operation is expected to continue at least until November. However, the work involves cranes, the operation of which depends on the weather, and Tepco said "safety will take precedence over schedules".

"As the work is taking place outdoors, multiple measures are in place to protect the environment and worker health by preventing the scattering of contaminated dust," Tepco said. "Anti-scattering agents are being used to keep dust down, small pieces of rubble that can create dust are being vacuumed, and mist sprinklers are used inside the building cover in conjunction with the demolition work."

Tepco said: “This major step toward fuel removal represents important progress.” Once the wall panels are removed, pillars and beams will be taken down and new wind screens will be installed, the company added.