Right, radioactivity is not the purpose of using DU in sabot tank rounds but it’s there nonetheless. DU has 60% of the radioactivity of natural uranium per the article below. So safer than uranium but not as safe as lead or steel I guess in terms of radiation.Pretty much everything metallic is "mildly radioactive". DU is used for "weight" and some pyrotechnic results inside the target as I understand it. Not radioactive results.
Depleted uranium - Wikipedia
en.wikipedia.org