Efforts to improve safety
Dismantling of the Unit 1/2 exhaust stack
There are four exhaust stacks used to expel air from the reactor buildings etc. at the Fukushima Daiichi Nuclear Power Station. In August 2019 we began dismantling the upper half (approx. 60m) of one of these stacks, the Unit 1/2 exhaust stack, in order to improve the safety of decommissioning work even though we have confirmed that the stack has sufficient seismic resistance, and completed the task in May 2020.
A dedicated dismantling machine was being used to alternately cut the exhaust stack body and supporting steel tower 2~4m at a time starting from the top. The dismantling machine was remotely operated in order to minimize worker exposure during this task.
Anti-dispersion agents were sprayed and the dust generated by the cutting process was suctioned up to suppress the dispersion of radioactive materials.
We had assessed the impact of exhaust stack dismantling on the surrounding environment to be minimal, but nevertheless we were constantly monitoring the concentration of radioactive materials in dust using dust monitors as we move forward with this project while prioritizing safety.
