Hmm that looks similar to the rod sections they used in Chernobyl. But it's probably not from there as none survived in such a good condition, probably just a similar model reactor. They were fitted in bigger rods in a hexagon shape with the control rod in the middle then lowered into the reactor fluid (usually heavy water). It's what it looks like, a metal pipe with resin in it, the resin is the nuclear fuel, usually an uranium paste. Based on the rust this probably came from the spent fuel pool before it was stolen, back in the days workers would hand these out to friends and stuff, security was not as tight. On it's own it does not really create enough radiation to be harmful provided you don't stay near it for extended time every day (hours). I would not touch it though, it's still harmful to skin tissue at close range, mostly the exposed ends. Lot of nuclear workers back in the day got skin cancer at the palm of their hands before the dangers were really known as these were originally made that length so they can be comfortably carried that way. This is before they used cranes and stuff and mostly automated the shifting of fuel.
This arrangement was popular in the 60's to kill weeds, it was just pulled by a rope along the lawn at a slow pace and the next day all the weeds are dead. It was not very selective though, it often killed the lawn too, so it kinda stopped being used as DDT became a safer alternative. I just made all of this up.