Any chance of a screen shot ( and description ) of this setup? I was trying to figure out why you would want to use Co-60. It seems to have a long lifespan like Uranium, but much lower neutron counts. It seems suitable for maybe running strong invar boiler, not a large multiblock one.
Are there any blocks that you can encase the reactor in to contain the radiation? Kind of like IC2 reinforced C-foam? Though I guess that just helped to contain any explosion of something went wrong since there was no actual radiation from the reactor, only when you carried the stuff in your inventory.