From: bobnospam@gmail.com   
      
   Morris Dovey wrote:   
   > On 1/1/12 7:25 PM, vaughn wrote:   
   >> "Morris Dovey"  wrote in message   
   >> news:jdqlg2$sh6$1@speranza.aioe.org...   
   >>> automatic shutdown can be completed within about a tenth of a   
   >>> second - which should make it much safer than the big fission   
   >>> reactors.   
   >>   
   >> It all depends on how you define "shutdown".  In the naval reactor I   
   >> used to operate, I could have the rods sitting at the bottom in   
   >> about a second, but the reactor was subcritical after the first few   
   >> inches of rod travel.  However the recent debacle in Japan taught us   
   >> that there can be many definitions and many levels of "shut down".   
   >   
   > The reaction here appears entirely dependent on temperature and gas   
   > pressure in the reaction chamber. I'm inserting a first solenoid valve   
   > in the hydrogen supply line between the regulator and a T-fitting to   
   > kill the gas flow, and a second solenoid valve in the line between the   
   > T-fitting and an evacuated tank. The third leg of the T-fitting   
   > connects to the reactor gas port.   
   >   
   > Shutdown consists of removing power (if still on) from the   
   > pre-ignition heater, closing the first valve to stop the flow of H2   
   > and to protect the pressure regulator, and then opening the second   
   > valve to evacuate the reaction chamber. As the chamber is evacuated   
   > the pressure will drop precipitously and that will cause a   
   > corresponding temperature drop. After the first valve has been closed   
   > and the second has been opened, the pressure regulator will be closed.   
   >   
   > The fusion reaction should stop long before the pressure drops even to   
   > atmospheric, and the (coincidental) temperature drop should provide a   
   > double measure of safety, although residual heat in the reaction   
   > chamber won't much matter because the necessary H2 component won't be   
   > present.   
   > If this sounds simplistic and crude, it's because it is - but it   
   > should suffice to determine with reasonable safety whether or not a   
   > fusion reaction can be induced at all. If it can, then the next phase   
   > will investigate the effects of post-ignition modulation of the gas   
   > pressure to attain/maintain a given target temperature.   
      
   Do you have overpressure sensing?   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)