10 CFR 20 Wording for Radiation Areas

[RFaunt]

In 10 CFR 20, why are the definitions for each of the radiation areas worded specifically to say "x amount of rem/rad in 1 hour" vice a unit per measurement of time (rem/hr)? I know why VHRAs are in rads, but I'm trying to wrap my head around the "in 1 hour" instead of rem/hr.

[Rennhack]

In 10 CFR 120, why are the definitions for each of the radiation areas worded specifically to say "x amount of rem/rad in 1 hour" vice a unit per measurement of time (rem/hr)? I know why VHRAs are in rads, but I'm trying to wrap my head around the "in 1 hour" instead of rem/hr.

/hr = in 1 hour

Regulations have to be exact and specific.  "/hr" is short hand for 'per 1 hour', but is not defined in the code, so it can not be used.

[etm]

Also acknowledges pulsed power machines that do not generate radiation at a constant rate.

[atomicarcheologist]

Also acknowledges pulsed power machines that do not generate radiation at a constant rate.

Going along with this assertion; "per" indicates a rate while "in" is  a function word indicative of a limit and in these regs that would be one hour.

[Marlin]

To expand on etm's post application of dose in one hour apply more to control of sources and radiation generators than power plants. Most plants write their procedures to which they must comply in mr/hr and entities such as radiographers write theirs to the letter of the law and comply with charts of exposure time to comply, i.e. 60 mr/hr in a 10 minute exposure is 10 mr in one hour.

10 CFR 20

[RFaunt]

Thank you to everyone for the great input on this. It's amazing how quickly everyone jumped to respond; now I'm a slightly less dim bulb.

10 CFR 20

You got me, Marlin. I went back and fixed it in the topic and the original post. I'm still trying to beat the 29 CFR 1910.120 out of myself.