I am trying to find cessium(sic) free cacao beans or nibs.
Any cacao beans or nibs from 2010- or earlier- before fukishima?
I don't have any beans from that time period. And you are unlikely to find any. Hurricane Sandy from 2012 wiped out nearly all the back stock that was stored on the USA east coast.
But also, although there is valid concern not wanting to eat radioactive cesium, there is no data I have seen to think there is any cesium in any cocoa beans above natural levels from Fukishima.
Personally, I believe your best bet is to simply pick a bean not from the Asia area (like Africa or South and Central America) and have it tested. It's the only way to be sure. Everything else is speculation.