Plasma plant starts operations in Bulgaria

A plasma melting facility at Bulgaria's Kozloduy nuclear power plant has started operations, heralding a breakthrough in nuclear waste disposal to boost the decommissioning process, the European Bank for Reconstruction and Development (EBRD) announced today.

Decommissioning work is under way at four of Kozloduy's six units (Image: EBRD)

The technology allows for treatment of waste with a minimum risk of radioactive contamination, the EBRD said, adding that, 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. Moreover, 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", it said.

The results of successful operational testing of the facility, which has a capacity of up to 250 tonnes per year, were presented today to the Assembly of Contributors of the EBRD-managed Kozloduy International Decommissioning Support Fund (KIDSF).

"Using plasma technology, the facility will significantly reduce the volume of low- and intermediate-level radioactive waste from the Kozloduy reactors 1 to 4, which were shut down between 2002 and 2006, and reactors 5 and 6, which are in operation," the London-based bank said.

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 plasma plant will treat waste from both 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 Ingenier?-a y Construcci??n (Spain) and Belgoprocess (Belgium), with Iberdrola the engineering company and Belgoprocess the process provider. The total cost of the plant is about EUR31 million, 35% of which is funded by the Bulgarian government and 65% by the KIDSF. It will be operated by the State Enterprise Radioactive Waste (SERAW) entity, which is responsible for the decommissioning of Kozloduy units 1 to 4 and the national radioactive waste disposal facility.

The Bulgarian nuclear power plant is home to six Soviet-designed reactors. Units 1 to 4 are VVER-440 reactors which are currently being decommissioned with the support of the international donor community led by the European Union through the KIDSF.

The KIDSF was established at the EBRD in 2001. More than EUR900 million has been contributed largely by the European Commission as well as by Austria, Belgium, Denmark, France, Greece, Ireland, the Netherlands, Spain, Switzerland and the UK.

Researched and writtenby World Nuclear News