The Technical Research Centre of Finland, VTT has developed a low-temperature plasma burning process for controlled and safe incineration of water purification resin used in the primary circuit of nuclear power plants. Storing radioactive waste in the form of ash takes less space and is easier to manage. VTT and its partners have signed an agreement to build a half-scale plasma burning process pilot.
Resin is used for purification of primary circuit water of nuclear power plants, which makes the resin radioactive. The level of its radioactivity does not decrease in incineration, but the volume of the radioactive waste will decrease to at least a tenth of its original volume reducing considerably the storage and final disposal costs for the nuclear power plant. Resin is an organic product and radiation induces gas generation in it, which may be problematic in long-term storage and in final disposal.
Plasma burning enables controlled and safe incineration of radioactive resin. The resin is incinerated in a subatmospheric pressure in a chamber, which enables the maintenance of sufficiently low temperatures. The radioactive ash resulting from the incineration is chemically more stable than resin and radiation does not generate gas in ash. The ash can, for instance, be solidified in concrete which will make the final waste product safe for storage.
In accordance with the project agreement a half-scale plasma burning pilot process will be built on VTT’s premises. The aim of the pilot project is to prove the efficacy of the process as a full-scale industrial process and also to optimise the process parameters for the building of an industrial burning process. The pilot project is based on experimental research carried out by VTT and on supporting model calculations according to which the process could be implemented on an industrial scale.
The pilot project’s duration will be two years. The aim is to have a commercial process ready in five years. Based on market research the process should have international market potential, especially in Europe.
The aim is to build a light process which could be implemented for the needs of one nuclear power plant site. Transportation of radioactive waste will be avoided, and it should be cost-effective to incinerate the waste on the plant site. It may also be possible to build the process in a transport container so as to provide incineration services to several NPP sites with one process unit.
The project is managed by Finex Oy, which manufactures ion exchange resins in Finland. The other cooperation partners are TVO, Fortum Generation and Tekes.