11 Jul (NucNet): A €31m plasma melting plant has started operations at the site of the Kozloduy nuclear power station in what has been called a breakthrough for Bulgaria in the treatment and disposal of radioactive waste.
Using plasma technology, the facility will significantly reduce the volume of low- and intermediate-level radioactive waste from Kozloduy units 1 to 4, which were shut down between 2002 and 2006 and are being decommissioned, and units 5 and 6, which remain in commercial operation, said the European Bank for Reconstruction and Development (EBRD).
The new facility is part-funded through the Kozloduy International Decommissioning Support Fund (KIDSF), which is managed by the EBRD.
The plant has a capacity of up to 250 tonnes per year. In the plasma, metals are melted and oxidised. Concrete debris, sand, inorganic granulates, insulation material and asbestos are melted. They are transformed into a chemically inert and amorphous glassy slag. Liquids and organic materials are vapourised so the final product is organics-free.
The technology allows for treatment of waste with a minimum risk of radioactive contamination, the EBRD said. As the final waste form is free from organics and liquids, it will meet strict quality and stability requirements for long-term storage or final disposal.
Historical radioactive waste conditioned in a bituminous or concrete matrix can be retreated in a plasma facility which makes the new technology potentially widely applicable beyond Kozloduy.
The plasma plant will treat waste from units in decommissioning and units in operation. A new national radioactive waste repository is under construction and commissioning is scheduled for 2021.
The facility is a joint venture of Iberdrola Ingeniería y Construcción (Spain) and Belgoprocess (Belgium), with Iberdrola the engineering company and Belgoprocess the process provider.
The EBRD said the total cost of the plant is about €31m, 35% of which is funded by the government of Bulgaria and 65% by the KIDSF.
The plasma melting technology being used was developed in the 1990s. The first industry-sized unit started operation at Zwilag in Switzerland in 2004.
