Abstract
It was revealed in 2002 that a considerable number of transformers and capacitors were unintentionally contaminated with small amounts of PCBs. The main cause of this contamination is presumed to be the use of recycled insulating oils in production of the machinery, which continued since 1990. The amount is estimated at approximately 1.2 million units for transformers and capacitors and 1,400km for oil-filled ground cables. To promote the appropriate disposal of such a huge amount while keeping the PCB level of the wastes to a minimum, the Ministry of the Environment took measures to develop a Minister’s certification system in compliance with the Waste Management and Public Cleansing Law of November 2009. At present, 35 certified operators have been permitted by prefectural governors to detoxify the waste through incineration and washing processes. In addition, an effective process called ‘energized natural circulation washing’ can also be applied for cleansing PCB contaminated transformers in-use. To meet the regulated deadline for PCB waste elimination, the end of March 2027, further new actions will be required including the promotion of mechanical surveys to check for pollution and development of the capacities and various applicable processes for detoxification.
