SU502558A1 - Method of preparing radioactive compounds based on soft grade bitumens for teeming to cooled containers - Google Patents

Description

one

The invention relates to methods for the preparation of radioactive waste for perpetual disposal. For the disposal of low and medium activity wastes, at present in industrialized countries, waste is fixed in organic binders, mainly bitumens. The resulting mixture is poured into barrels, which are buried. The storage factor in this case does not exceed 0.4.

Vonros about the increase in the coefficient of use of the repository and the refusal to use a rigid standard container (for example, boxes) was supposed to be solved by transporting the bituminous compound through pipelines from the apparatus to the repository. However, the possibility of a mixture thickening in the pipeline in case of various malfunctions, as well as the remoteness of the burial grounds from the bituminization plants, was forced to refuse such transportation. The use of soft shells for the transport of blocks of a radioactive bitumen compound melted by the passage of time into a monolith, due to the lack of a sufficient quantity and necessary

for the range, both in terms of properties and format of synthetic film materials, for the near term appears problematic and uneconomical compared to the proposed

in a way.

It is known that for packaging highly viscous bitumen solid at room temperature with an asphaltene content of more than 30 wt. % and coal tar pitch serves them on a cooled surface, covered with anti-adhesive lubricant.

However, this method is unsuitable for packaging soft bitumens due to high adhesion to the container walls due to the lack of soft bitumens of the components structuring the system when it is cooled (in this case, the lack of asphaltenes). The essence of the invention is that certain substances are added to fix the soft wastes of radioactive waste, so that when heated above the softening temperature the compounds obtained after the addition have a low viscosity typical of soft bitumens, and when cooled below the melting point

in the compound, a structural dispersion phase would stand out. The formation of such a phase drastically reduces the adhesion of the binder to the container walls, which makes it possible to obtain blocks that are easily discharged from the cooled container. Such blocks without rigid containers in the form of barrels, being placed in a burial ground, eventually spread into a monolith, which increases the fill factor of the burial ground.

Bitumen binders with a low content of asphaltenes (less than 30 wt.%) Introduce organic substances, for example indene marmarone resins, paraffins, which, together with the asphaltenes present (in total more than 30 wt.%), When cooled below the softening temperature of the compound, are able to form in the bulk of the compound, the structuring dispersion phase. Then the mixture together with the radioactive waste is melted: and poured into containers cooled below the softening temperature, which are not coated with grease from the inside, and which do not have anti-adhesive inserts. The cooling unit is removed from the collection and sent to the burial site without a shell.

Claims (1)

Invention Formula A method for preparing soft grade bitumen-based radioactive compounds for casting into cooled containers by reducing adhesion to the container walls, characterized in that paraffin or indene-maronic resins are added to the compound in order to bury the compound in the monolith burial. which, together with bitumen asphaltenes, is not less than 30 wt. %