Effects of Radiation on Electronic Equipment

[broseus%nihrsb.dnet@dxi.nih.gov (Roger W. Broseus, Ph.D.; RB27m@NIH.GOV)]

Radiation Effects on Electronic Equipment

The original post on this subject related to effects of background
radiation on electronic components.  The discussion has expanded
(degenerated <g>) into a more general discussion of radiation
effects on electronics, e.g., with statements appearing like: 

     The effect of very high levels of radiation on
     commercial computers was investigated as part of the
     SDI project, more than 10 years ago.  I do not know
     the results, but the fact that they used microamps of
     accelerator beam, i.e. megarads, suggests that the
     effects of background radiation are too small to
     measure.
     
While I agree with the general thrust of this statement, CAUTION
is advised when radiation fields are high, particularly if safety
systems are involved.  Solid state devices (read: transistors and
integrated circuits!)  are particularly sensitive to high
radiation doses, i.e., as "low" as 10 Gy.  (Ref: NCRP Report No. 
88, "Radiation Alarms and Control Systems").

I am also aware of anecdotal examples of radiation damage causing
problems, e.g., with a robot designed for automated retrieval and
transfer of targets to a shielded container on a cart for
transport to a hot cell; this occurred at a radionuclide
production facility.  At high doses, other, unexpected effects can
occur on non-electronic components, e.g., the polymerization of
oils on rods used to move sealed sources in self-contained
irradiators.

HPS and engineers should attend to these concerns when designing
safety systems.  Readers of RADSAFE should be aware of the
admonition to be careful of what you read on the Net; in this
case, to not extrapolate based on fragmentary information.

Roger W.  Broseus
Kindly direct replies to RogerB@cais.com; non-constructive replies
should be directed to /dev/null.
Opinions expressed herein are solely those of the author.