TOKYO -- Tokyo Electric Power Co. (TEPCO) launched demolition work on Aug. 1 to remove the upper half of the about 120-meter-tall exhaust stack for the No. 1 and 2 reactors at Fukushima Daiichi Nuclear Power Station.
The structure was used as a vent to reduce pressure in the reactor containment vessels during the 2011 meltdown disaster, but will be dismantled due to the risk that fractures in the structure's pillar could cause it to collapse in an earthquake.
On this day, workers removed a portion of a ladder and other equipment fixed to the exhaust stack. TEPCO planned to start disassembling the upper half of the structure on Aug. 2. It aims to complete the work in fiscal 2019.
Radiation is still high in areas around the stack. To prevent them from becoming exposed to radiation, workers use remote-controlled cutting equipment from inside a large bus parked about 200 meters from the structure. But the work on this day was temporarily suspended due to equipment failure.
The cutting apparatus, equipped with tools including a blade, was developed by Able Co., a local construction firm based in Okuma, Fukushima Prefecture, northeastern Japan. TEPCO planned to slice off the exhaust stack in about 2-meter layers starting Aug. 2.
Plant director Tomohiko Isogai stated, "It's an important task to reduce risks in proceeding with decommissioning work. We will give the highest priority to safety."
The demolition of the exhaust stack had originally been scheduled to begin in May, but it became evident at the last minute that the crane slated to hoist up the cutting equipment was not tall enough. As workers had to implement measures to make up for the lack of height, such as bringing the crane closer to the structure, the work was postponed until August.
(Japanese original by Suzuko Araki, Science & Environment News Department)