Not sure if mod author is aware, or if this is even the right place to mention this, but as of build #769 of IC2_Experimental crafting of the MT Core is broken due to the changes made to the Thick Neutron Reflector.
Link to build log http://jenkins.ic2.player.to/job/IC2_experimental/769/
Again, apologies if this post isn't up to snuff, first time poster