Re: Q: "Tandetron" accelerator and regs

[Steven Hand <SHAND%UMDACC.bitnet@vmd.cso.uiuc.edu>]

From: shand


     Greeting Keith,

                     In case you do not remember I just talked to you
     a few weeks ago concerning the transfer of some material to College
     Park.

     Please feel free to question the safety of our installation any time
     that I post something here, I have learned a great deal from reading
     the correspondences and hope to continue to do so.

     The interlocks do function.  They are key-carded, so that only those
     individuals with the coded cards may enter the room.  The beam is
     terminated if the door is opened.  The "state certified" inspector
     for our radiation producing machines did not see any problem with
     the console being located in the room, nor with the location of the
     console being so close to the target.  Permanent ion chambers from
     Eberline are set up at the tank, the tube accessing the target, and
     the console where the operator sits.  These are alarmed.  Perhaps the
     nature of the machine itself lends to allowing the console in its
     location.  The Pelletrons are low energy, producing no levels above
     the instrument backgrounds for the Eberlines.  The beam is fully
     contained and shielded.  No change in configuration has been made to
     the beam line.

     Your response prompted me to walk over an visit the facility to refresh
     myself with its operation.

     What I found:  1. The portable instrument was out of calibration.
     2. The portable instrument was not being routinely checked before
     each use.  3. During recalibration of the permanent monitors the
     portable monitor was not being used by the operator at the console
     nor to check the permanent positions of the missing monitors that
     were out for calibration. 4. The operator did not know the alarm
     setting for the permanent monitors.  5. The permanent monitors are
     set for audible alarm only, however there are no instructions in
     the standard operating procedures, nor in the emergency procedures
     telling the operator what to do if the alarm goes off.
     The operators are not checking the safety interlocks, warning devices
     and monitors at least every 3 months and recording these in a log.
     Some periods were not recorded nor conducted.

     Action from our office on the above items:  General - Immediately
     increase frequency of visits to the facility to check on all items
     with particular attention to those listed above. 1.  Replacement
     of the ion chamber with a loan from our department until the
     facility portable detector is calibrated.  2. Loan from our department
     of check source to check response of detector - and further requirement
     for recording the check on the instrument. 3.Amend SOP to include
     use of portable detector by operator at all times. 4. Statement of
     set point for alarm in the calibration records available at the
     console. 5. Amendment of Emergency procedure including response to
     alarm.  In addition to this amendment - alarm of the console ion
     chamber will terminate the beam.  Alarm of the tank and target
     area chambers will instruct the operator to assess the levels and
     conduct a survey with the portable detector around the area in
     question.

     Obviously our office was not up to par on this facility either.

     Thank you for the question and comment.  Please question and comment
     on our response as well concerning this "visit."  Thanks for the help
     in advance.
                             steve
                             UMCP