NCRP Report #147 - Radiation Shielding for Medical Instalations

P=0.1 mGy/y for Uncontrolled areas satisfies0.25 mSv/y Public Dose Limit – cont.– Assuming conservatively high occupancy factors– In the USA, Pb sheets come in quantizedthicknesses (e.g. 1/32 inch, 1/16 inch, etc). Usingthe next greater thickness will shield to muchlower levels than P– Assuming minimum distances from source topersonnel in occupied areas– At