FLAMMABLE GAS SAFETY, RICH
--------------------------

1. Safety requests at 7/3 meeting (hoping the list is
   complete):

   - updated scheme of CH4 recirculation system:
     to be asked to Bosteels and be obtained when he has time
  
   - reduce Ar flux (presently 200 l/h) when power is 
     off (no compressor): we have discussed it at length and we 
     would like to keep the figure; today, we do not know yet the
     tightness of the entire system (8 photodetectors); more, the 
     volume of 1 detector is ~40 l and we consider that flushing at 
     25 l/h is not exagerating

   - we will change the wrong N2 labels to Ar on CH4 system
 
   - electrical equipments  of CH4 recirculation rack, collect 
     information to access danger level; I have prepared a list 
     of elements and sent it to Michel; the list includes:

     - electrovalve on the Ar line (open when power off)
     - electrovalve at compressor (open when the compressor is started)
     - O2 trace analyser
     - H2O trace analyser
     - 2 pressure switches
     - 2 mass flowmeters with valve 
     - compressor
     - 8 resistors to measure return flow 

   - to have the flux measured in the 8 return lines from the 
     detectors: Michel confims that the devices are ready, but 
     now he has no manpower to have it installed (perhaps in April...);
     in any case, asymptotically they will be there

   - second major question: CH4 system controlled by which PLC?
     also this has been considered at length, and we would prefer 
     to stay connected to detector PLC (as it is now); the reasons
     are:

     - no UPS or diesel is needed for this gas system (the various 
       accidents happened during last Summer have obliged us 
       to have the emergency Ar line which is opened as soon as 
       there is a power failure)
     - if certain alarm conditions impose to switch off all the
       power PLC controlled or the PLC itself, this is not tolerable 
       for the radiator gas system: better if radiator gas and its
       PLC stand alone.