It would be neat if there were a config setting that would massively increase the radius of the radiation released from an exploded RBMK and increase the explosion damage the RBMK does to any blocks above it... After all, our only example of an RBMK explosion is Chornobyl, and that resulted in the roof being thoroughly blown apart, as well as very intense fallout spreading all across Prypiat and Red Forest, wind taking it into Belarus and up toward parts of Germany, Poland, and Scandinavia. To what ultimately amounts to thousands of kilometers... Granted the fallout was very dilute by the point it was blown out of Ukraine, but my point still stands. I think it would be neat if the radiation from an RBMK could extend a few thousand blocks away from the burnt-out husk of the reactor.

might not be hard to impliment; just treat it as a massive dirty (salted) bomb; it would need extra stuff done to calculate the amount of RADS spewed out depending on the fuel melted and stuff