Re: Q: "Tandetron" accelerator and regs

[welch@CEBAF.GOV (welch)]

Steve, 

I'm not questioning the safety of your installation, but aren't you kind of
defeating the point of the interlocks by having the operator in the
interlocked space when the point of having them is to "shut down the machine
under conditions of barrier pentration" ????
 
Or am I missing something.

How do your regulators look at this?

Keith Welch
welch@cebaf.gov
-----------------------------------------------------------------------
>From: shand
>
>          Hi Melissa:
>
>                   We have a "Pelletron" 1.7 Mev accelerator here at
>          UMCP.  We are also an agreement state.  Specific authorized
>          use at this time (in house under our license) is for hydrogen
>          and helium ions as well.  Our state regulations call for
>          an interlock: "Each entrance into a target room ... shall be
>          provided with a safety interlock that shuts down the machine
>          under conditions of barrier penetration."  There are two
>          entrances to the room, each is interlocked.  The console is
>          located about 5 feet from the target area, in the same room.
>          The initial run found a 1000 mr/hr area between the plasma
>          source and the bending magnet.  This area we wrapped in lead
>          and reduced to less than 30 mR/hr on contact.  At one meter
>          from the tank the exposure rate was 0.05 mr/hr.  The highest
>          reading on the tank was 0.2 mr/hr.
>
>          A Dr. Correl at the US Naval Academy in Annapolis, Maryland
>          was very helpful with our understanding of the machine.  We
>          visited a 2 Mev Pelletron there and observed the warning
>          light operation, door interlocks testing and measurments
>          while in operation.  Their console was also in the room
>          and located about 20 feet from the target area.
>
>          If you would like, I can fax a schematic of our machine, the
>          exposure rates at various points, etc...
>
>                                 Hope this was helpful
>
>                                 steve hand
>UMCP
>
>