Loviisa liquid waste facility starts operation

The Finnish regulator has given utility Fortum permission to start full operation of the liquid radioactive waste solidification facility at its Loviisa nuclear power plant. Commissioning of the waste facility began in 2006.

Finland's radiation and nuclear safety authority (STUK) completed its safety assessment of the solidification facility last month and granted Fortum permission on 15 February to begin operating. The solidification process - which involves cementing the waste into containers for final disposal - is highly automated and the process is controlled from a control room within the facility.

Construction of the solidification facility began in 2004. STUK said it has overseen the design, construction and commissioning of the facility.

The solidification is designed to process low- and intermediate-level liquid waste generated during the operation and decommissioning of the two-unit Loviisa plant. This waste primarily consists of ion exchange resins used in the purification of process water as well as sludge from the bottom of the evaporator concentrate tanks.

Some 900 cubic meters of intermediate-level radioactive ion exchange resins and evaporator concentrates for solidification have accumulated at the Loviisa site during the plant's operation. The full-scale processing of this waste can now begin.

Fortum said it aims to process all the liquid waste before the operating licence of Loviisa unit 1 expires in 2027. When decommissioning of the plant begins, the solidification plant will then process the liquid waste generated in the purging of the reactor system and in dismantling work.

Deputy director of the Loviisa plant Thomas Buddas said, "The Loviisa power plant's solidification plant is a pilot plant; its planning and successful implementation is the result of the long-term development efforts by Fortum's own competent personnel. The plant's commissioning phase started in 2006; during the test runs, the solidification recipes were developed and tested and the manufacturing method for the final disposal containers and the resin transfer systems were improved."

He added, "The waste will be cemented directly in final disposal containers, which, after intermediate storage, will be deposited into the final repository for plant waste, located on-site in the power plant area." Buddas noted the advantages of cementation include fire safety and the concrete's ability to effectively absorb radioactive materials. "The waste can be handled in small batches, making the process safe and easy to control", he said.

The Loviisa units are unique in that the reactors are of the Russian VVER-440 design, but have Western I&C systems and enhanced safety features, such as strengthened containments. Unit 1 was commissioned in 1977 and unit 2 in 1981. Licence extensions were issued in July 2007, enabling the units to operate until 2027 and 2030, respectively.

Researched and written
by World Nuclear News