Plasma waste processing is the newest method of disposal of solid waste, which essentially is a waste gasification. This method is the most promising among the recycling solutions, since such production does not set strict requirements to the feedstock, and yields a secondary energy in the form of hot steam or hot water to supply them to the final consumer, as well as a range of secondary products, such as granulated slag or ceramic tiles.
In fact, this is the best option for complex processing of garbage, fully environmentally friendly that produces heat and a variety of useful products from the most junky materials – household waste. With the emergence of such innovators as Simdean, the company famous for its industrial waste disposal, plasma waste disposal and research achievements, the method became more cost effective. However, it is still not a panacea.
Dealing with radioactive waste
So how is the problem of radioactive waste is going to be solved? It depends on the category, the class of such waste – low-level, intermediate-level and high-level. The simplest mission is the utilization of the first two classes. It should be noted that, depending on their chemical composition radioactive waste is divided into short-lived (from short half-life) and long-lived (long half-life). In the first case, the easiest way is the temporary storage of radioactive materials at special sites in airtight containers. After a certain period of time when disintegration of hazardous substances takes place, the remaining materials are not dangerous and can be disposed of as ordinary waste.
This is the approach with most technical and medical radiation sources that contain only short lived isotopes with a half-life maximum of a few years. In this case standard metal barrels of 200 liters are used, with the groundwork cemented or asphalted to prevent them from falling out of the container.
The procedure for disposal of nuclear power plants is much more complex and requires more attention – unfortunately, plasma processing is still useless when it comes to such missions. Therefore, this procedure is performed only on special plants, just a few facilities around the world. Here, by means of special chemical treatment technology the most of radioactive substances is extracted for their reuse. Most modern methods using ion exchange membranes allow reuse to 95% of all radioactive materials. In this case radioactive waste is significantly reduced in volume, however it cannot be deactivated completely. That’s why the next step is carried out with preparation of waste disposal for storage. And given that nuclear waste have a long half-life, the storage can be called eternal.
Long-term storage of radioactive waste require maintenances in the storage that will not react and break for a long time. One way to achieve this state is vitrification – in Sellafield, United a mixture of calcined sugar is used for treatment. Calcination involves passing the waste through a heated rotary tube and aims to water evaporation and denitrogenation fission products to improve stability of the resulting glassy mass.