Radiological protection procedures related to the handling of different uranium compounds enriched 20% in 235U

The obtainment of U3O8 starting from UF6 comprises a wet stage consisting in the extraction of gaseous UF6 by heating at 60-80 deg C, its hydrolysis to uranyl fluoride and precipitation to ammonium diuranate, and a dry stage where conversion to U3O8 powder takes place through calcination at 800 deg C and further treatment until the attainment of the raw material for fabrication of fuel elements. The treatment of these compounds upon the stated process involves a prevailing toxicological risk due to exposition to UF6, FH and UO2F2, and a radiological risk of fundamentally non-stochastic nature for the critical accident and stochastic nature for the dispersion of materials. Exposition to UF6 constitutes an emergency because in a few minutes UF6, FH and F2UO2 incorporations can reach toxicological limits. On the other hand, these incorporations represent only 10-2 times the ALI