tdh@frog.UUCP (T. Dave Hudson) (07/17/86)
> the power density of the Soviet graphite reactors > is so high, that only continuos cooling prevents the temperature > from rising to the ignition point of the graphite. I was told by a physicist that the purpose of the cooling was the greater power density (due to convection?) available with it. The reactor at Chernobyl was supposedly running so cool that a thermal release of Wigner (sp?) energy (The release was called "Wigner relaxation".) in the graphite had to be performed periodically by warming the reactor up. (Graphite reactors can relax continuously if run warm enough. The energy is stored as displacements of atoms within the graphite lattice and is due to nuclear bombardment.) The alternative of no maintenance leads to a catastrophic release of the stored energy. Presumably, botched maintenance could too. David Hudson
throopw@dg_rtp.UUCP (Wayne Throop) (07/21/86)
> tdh@frog.UUCP (David Hudson) >> the power density of the Soviet graphite reactors >> is so high, that only continuos cooling prevents the temperature >> from rising to the ignition point of the graphite. > I was told by a physicist that the purpose of the cooling was the > greater power density (due to convection?) available with it. The > reactor at Chernobyl was supposedly running so cool that a thermal > release of Wigner (sp?) energy (The release was called "Wigner > relaxation".) in the graphite had to be performed periodically by > warming the reactor up. (Graphite reactors can relax continuously if > run warm enough. The energy is stored as displacements of atoms > within the graphite lattice and is due to nuclear bombardment.) The > alternative of no maintenance leads to a catastrophic release of the > stored energy. Presumably, botched maintenance could too. Wrongo (according to Science News of a while back, if memory serves). In many reactors in the "west", the temperature cycling in graphite reactors must be done, and early speculation was that some error during such a cycle was what had done Chernobyl in. But it turned out not to be the case. Indeed, it turns out that Cernobyl operates above the temperature needed to thermally "relax" the graphite, somewhat hotter than "western" reactors of similar design. (Don't know about the power density though... sounds like a lunatic design if true.) -- "You are my Density!" --- from Back to the Future -- Wayne Throop <the-known-world>!mcnc!rti-sel!dg_rtp!throopw