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Essay Question - Very High Radiation Area

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 Mike posted a couple of these a few weeks back.  I thought this would be a good one for the group.

Units associated with a Very High Radiation Area - Rad/Hr

 This topic was generated from another thread and may make a few people scratch there head and wonder why.  The answer is actually quite simple.  

 As per the definition of a Very High Radiation Area, the unit of measure is Rad/Hr, not Rem/Hr.  Besides the definition, a special note also addresses the use of the term " Rad ".  

 Radiation Area's and High Radiation Area's, use the unit Rem/Hr, not Rad!  Since all of these definitions address the concern for Exposure to personel, why does the unit change?  

 If you get that one, give your best guess why the definition includes the stipulation, " External to the Body "?

 Give it your best shot!

I've been told thatat the higher levels, the math goes out the window, that the conversionfactors are not applicable.... I don't but that.  Ergs/gm are Ergs/gm.

However, a VHRA would bot be due toalpha, they can't travel tyhat far... and few Beta's can as well.  But those gamma's can.... (with a 1:1 Ration q).  This leaves us with those Neutrons with a 10-20 Q.....hmmmmm  

The problem is in converting exposure in air to absorbed dose.  At levels associated with Very High Radiation Areas it would be not be necessary to determine the absorbed dose, only that the warning should be in place.  If someone is exposed to those levels then medical treatment is going to be undertaken and the actual damage will be the concern, not the precise meter reading in such a high dose field.
The nitty-gritty explanation lies somewhere in Kerma, Bragg-Gray cavity theory, and electronic equilibrium.  
Hopefully someone else will chime in with a comprehensive explanation.

at a time like this, i can only ask, "what happened to moe?"

Almost off topic....different plants seem to have different ways of deciding what is VHRA.
I recieved a briefing to enter VHRA at quad...I think it was in the circulation pump room?
Anyways, when we finally found the surveys, the highest dose in the room was 150mR/hr.
Smearable was pretty low, but we were crawling all over the top of the pumps (heat was the worst).

What are the "usual" limits for jumping from HR to VHR?


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