Criticality monitor at power reactors -Reply

[James Mallon <mallonj@myapc.com>]

In the past  I used the 20 rad guidance in part 70 as input  to alarm
setpoint calculations.  I conservatively assumed a 1/r2 falloff from the
surface of the spent fuel pool to the detector locations.  The facility that I
worked at had a number of detectors.  During different operational
modes (refueling) some of the detectors were shielded by components
staged for use during refueling.  

If we had less than two detectors available a portable ARM would be
placed by the spent fuel pool as a compensatory measure.  I hope this
helps, call if you have other questions

Jamie Mallon
Millennium Services Inc.
207-882-5643
mallonj@myapc.com