From: "Phil Bunch" pbunch at cts.com> on 2001.10.28 at 15:27:20(7698)|
Listening to a piece on NPR Friday afternoon they were discussing
various methods that may be used. The electron method may not work
well over the long run since electrons will not penetrate more than a
few inches of paper. That means they would have to lay the mail out
one or two layers thick. I don't know much about the existing mass
mail processing systems but I suspect they were not designed with this
in mind. Most likely mass transport is designed to use bags or boxes.
There may be key points in the system where the mail is one layer
thick but if so I'll bet it moves past that point vary rapidly. If it
goes by too fast, it may require a very dense beam since the effective
dose has to be time dependent.
The higher energy systems will penetrate several feet of mail and
appear to be a better choice. The dose received COULD depend on how
deep the object was in the pile. Those on the top layer might get
quite a dose while those on the bottom might receive less. Depending
on design this might not be a significant difference. If the dose
required to kill bacteria and/or viruses is relatively low one would
think they would design the system to handle as much bulk as possible.
At best sending seed would be a gamble.
If I recall correctly the report indicted that an electron system was
ready for commercial deployment but that due to this little problem
one should not go out an buy stock in the manufacturer just yet. The
high energy systems pose a greater exposure risk for mail handlers and
this will involve some serious design issues.
There are a lot of variables here!
Lemon Grove, California