It’s a little fuzzy, sure. That’s because I photographed it in its plastic pouch. So, sue me.
The event at Chernobyl happened 30 years ago now. This Russian-made pin was probably given to people who donated money to help those who had been displaced by the explosion and resulting radioactive contamination. It’s 3″ top to bottom and 1″ wide. Enamel on some sort of pot metal. Quite light.
It’s listed as being rare.
Uncle Bob's Pix 
Cool find, Bob!
I’ve actually had it for years. I bought it back when I used to get mailings from dealers about unusual offerings.