To: bentway who wrote (434140 ) 11/10/2008 12:21:54 PM From: combjelly Read Replies (1) | Respond to of 1574059 I dunno if you saw this, but remember the buried nuclear reactor that i-node posted yesterday? Here is one guy's take on the patents.No useful information on their website indeed, but you can get some from their pending patent , also available there. I gave it a cursory reading. It is a nuclear fission reactor which is supposed to be self-moderated by the uranium hydride (UH3) and self-regulated, as an increase in temperature would dissociate the hydride and make it sub-critical. It would require 5% enriched uranium as fuel, which is very similar to what is used in today's PWRs and is not very satisfactory in terms of natural resource usage (Pu or Th are considered as a variant). The coolant would be either liquid metal, which allegedly would not require any mechanical pump, or actively pumped nonhydrogenous fluid. This is very vague but maybe they wanted to keep the doors as open as possible in their patent. A 50% fuel burnup is claimed, which would be a dramatic improvement over PWRs. Reprocessing could be achieved by simple zone refining which is interesting but a bit in contradiction with the ideal of a sealed, non proliferant reactor. The capital cost is as low as $1m per MW which is very attractive, but I will remain skeptical until I know where I can buy one from. Uranium hydride was used in the 50s by Ed Teller in an alternative attempt to build atomic bombs. It turned out to be a failure, mocked by Enrico Fermi. BTW Hyperion's reactor bears some similarities with another concept by Teller, the already mentioned TWV, in that is self-regulated and underground. On the other hand, it differs from the TWR in that it is much smaller, relies on different regulation principles and requires enriched fuel and periodic refueling. The idea of making a source of energy out of a damp squib is appealing. Yet many question marks remain. And public acceptance is an issue. talk-polywell.org