Dioxin-contaminated Equipment Dismantling Work

Dismantling work of biomass power generation facility using construction scrap wood

The wood biomass facility being dismantled this time generated power through the combustion of scrap wood disposed of as industrial waste. The facility simultaneously supplied heat to the adjacent asphalt plant.

When material is combusted, small amounts of dioxins occur naturally. The amount of dioxins depends on the material being combusted and the combustion temperature. Dioxins also occur in the scrap wood combustion process, and this includes ash and other residues. As a result, it is necessary to remove the dioxins prior to dismantling the facility.

The scope of this construction work included large equipment and the dismantling of reinforced concrete buildings. Including the dioxin decontamination, it was expected to be an extremely difficult project from a safety standpoint. But our project track records in dismantling and construction were well-known, and we successfully received the order.

Dismantling work of the PC building

Dioxin decontamination

In order to prevent dioxin leaks during the dioxin decontamination, we created an exposure prevention cure covering the entire contaminated facility during decontamination. Construction workers wore personal protective equipment (chemical protective gear and air respirators etc.) in responding to the dioxin concentration during the decontamination work. The location of dioxin decontamination was mainly inside the facility where the use of heavy machinery is difficult. Therefore, all work had to be performed manually. Such working circumstance made this project more difficult from schedule and safety standpoints. In particular, the removal of fireproof materials inside equipment caused a delay in construction schedule due to the hardness of the fireproof material and the tight work areas. However, through reviews of the construction plan and schedule, we were able to complete the project without any incident.

Dioxin exposure prevention cure

Decontamination work

Dismantling work of large equipment and reinforced concrete buildings

After the decontamination of the biomass power generation facility was completed, we dismantled the large equipment and reinforced concrete buildings. Especially, the outdoor equipment was large and heavy, so a large size crane and special heavy machinery were used in its dismantling work. In order to prevent dust from scattering during concrete crushing in the dismantling work of the reinforced concrete building, we made thorough use of water spray. We completed the project with zero complaints from nearby companies.

In addition, we were able to remove the pipe supplying heat to the asphalt plant, which was under operation without any incident by implementation of thorough pre-meetings and careful construction planning taking into account maintenance work simultaneously performed by other companies. This was a difficult project including dismantling work and dioxin decontamination, but we were able to complete it one month ahead of schedule without any accidents or issues.

Before completion　

After completion