Test results on the development and elaboration of the UNEX process have shown that the treatment of 1 volume of feed HLW generates 0.5 volume of strip product containing recovered radionuclides, guanidine carbonate, DTPA and 4-5 g/L of non-radioactive metals. The well-known borosilicate — glass production technique was tested on this product. The main non-vola­tile components of the strip product are sodium (20%), potassium (40%) and iron (10%). Taking these into account, the composition of the flux for glass was determined: it contained silicon dioxide, boric acid, sodium nitrite and zinc oxide.

The glass production process included the following operations:

• drying of the strip product;

• calcination of residue at 700°C;

• preparation of the flux and its drying at 450°C;

• mixing of the calcinated residue with the flux at 1100-1200°C.

The borosilicate glass samples produced were homogeneous, did not contain any non-molten inclusions and did not crack in storage. 1 m3 of strip product produces 15-20 kg (~10 L) of borosilicate glass.