[krisoft]

Absolutely. And not without incidents: https://en.wikipedia.org/wiki/Lia_radiological_accident

Short summary: Soviet engineers installed RTG powered radio relays to support the construction of a damn in Georgia. Political instability lead to the abandonment of the RTGs. Someone scavenged the generators and removed the radioactive cores from them.

Two of the radioactive sources were discovered by men gathering firewood in the forest. They decided to bring them to their camp(!) and cozy up to them to keep warm during the night(!!). Despite showing symptoms of radiation poisoning they kept the cores on their person while loading their truck(!!!). They all suffered terrible radiation injuries.

There are more sources "lost" from the same batch which remains unaccounted for to this day.

[masklinn]

Yeah the URSS made routine use of RTGs throughout their territory (pretty logically as it's so vast and low-density electrification can't reach everywhere), and those routinely got misplaced. Things got worse after the fall of the URSS too e.g. a helo dropped two RTGs from 50m while airlifting them in 2004.