Reference : Radiation
Safety Limits
There's lots of various rules and regulations that you'll need to know for the boards. I've noticed that the hodgepodge of limits are hard to find. Here's a list of some of the most common limits, and I guarantee you'll get a few of these on your boards.
| Label |
Surface Limit |
TI |
| White I |
0.5 mR/hr |
N/A |
| Yellow II |
50 mR/hr |
1 |
| Yellow III |
200 mR/hr |
10 |
Note: The TI is really just the limit at 1 meter. If a question asks what is the limit for a Yellow II package at one meter, the answer is 1mR/hr. If someone asks what is the TI of a Yellow II package, the answer is 1 (no units.) Why would the DOT do this? Who knows, but you should know that TI has no units.
| Annual Limits for |
Limit |
| TEDE |
5 rem |
| DDE+CDE |
50 rem |
| LDE |
15 rem |
| SDE |
50 rem |
- For Minors: 10% of adult limits
- For Embryo/Fetus: 0.5 rem for entire pregnancy
Note: TEDE=total effective dose equivalent; DDE= deep dose equivalent; CDE = committed dose equivalent; LDE = lens dose equivalent; SDE = shallow dose equivalent.
| Annual Limits for |
Limit |
| TEDE (public) |
0.1 rem |
| Unrestricted Area |
<2 mR/hr |
| Someone Visiting a radiotreated patient |
0.5 rem |
| Special permission by NRC |
0.5 rem |
| Sign |
Limit |
Distance |
| Uncontrolled Area |
<2 mR/hr |
@30 cm |
| Radiation Area |
>5 mR/hr |
@30 cm |
| High Radiation Area |
>100 mR/hr |
@30 cm |
| Very High Radiation Area |
>500 RAD/hr |
@1 m |
|
Limit |
| In General |
<22dpm/cm^2 |
| Weekly Wipes |
<2200dpm/100cm^2 |
| Package Wipes |
<6600dpm/300cm^2 |
