Dynamics of Tc-99 transmutation under irradiation with thermal neutron
s having the spectrum hardness of 0.3 is calculated, and the yield of
stable Ru100-102 and its volume distribution in targets of different t
hickness are determined. After irradiation of targets from metallic te
chnetium 0-5 mm thick with a thermal fluence of about (5-10) x 10(22)
cm(-2) the maximum yield of Ru100-102 is reached corresponding to 97.5
-99% of all the nuclei of the target. For commercial applicability of
the resulting ruthenium, the content of actinides in the target before
transmutation should not exceed 5 x 10(-10) g g(-1) Tc-99, and the co
ntent of unchanged Tc-99 after processing of the irradiated target sho
uld be below 10(-5) g g(-1) Ru.