It is possible to bond alumina, such as a modified dogbone reactor directly to stainless tubing, using the proprietary S-bond alloy :
http://www.s-bond.com/blog/2011/04/04/ceramic-metal-bonding-part-one/ The advantage would be allowing a permanent fill port for hydrogen, along with a pressure gauge, and other feed-thru accommodations which are more easily ported into metal then into ceramic. The design problem would be in keeping this metal part of the reactor cooler than the rest of the reactor - and the simple solution for that is to add a long ceramic extension tube to the dogbone, which extension is not powered and it can be as long as the reactor itself with a decreasing temperature gradient, then to add the stainless plumbing to the far end of the ceramic extension tube using S-bond. This keeps the heated segment spatially removed from the stainless. There would be a hot-end and a cold-end, and the entire unit would be much longer. For any dogbone device to move towards commercialization, far more control must be implemented, including fuel availability and pressure - and this means adding hydrogen from a tank at a controlled pressure. A ceramic to metal bond is one way to do that. I am assuming that hydrogen is the only consumable, at least until testing from Parkhomov shows otherwise.
