Management of Commercially Generated Radioactive Waste - U.S. ...

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Part 20 of the Code of Federal Regulations (10 CFR 20). Title 10 is based on NCRP, ICRP
and FRC guidelines (25 F.R. 4402 et seq May 18, 1960) on radiation standards and the U.S.
Government has endorsed the model regulatory code of the United Nations, which closely fol-
lows ICRP philosophy. An excerpt from 10 CFR 20 follows:
20.101 Exposure of individuals to radiation in restricted areas.* (a) Except as provided
in paragraph (b) of this section, no licensee shall posses, use, or transfer
licensed material in such a manner as to cause any individual in a restricted area to
receive in any period of one calendar quarter from radioactive material and other
sources of radiaton in the licensee's possession a dose in excess of the limits specified
in the following table:
rem/calendar quarter (rem/year)
Whole body; head and trunk, active blood forming organs; lens of eyes, and
gonads . . 1-1/4 (5)
Hands and forearms; feet and ankles . . . . . . 18-3/4 (75)
Skin of whole body . . . . . . . . . . 7-1/2 (30)
(b) A licensee may permit an individual in a restricted area to receive a dose to the
whole body greater than that permitted under paragraph (a) of this section, provided:
(1) during any calendar quarter the dose to the whole body from radioactive material
and other sources of radiation in the licensee's possession shall not exceed 3 rems;
and
(2) the dose to the whole body, when added to the accumulated occupational dose to the
whole body, shall not exceed 5 (N-18) rems where "N" equals the individual's age in
years at his last birthday.
*"Restricted Area" means any area whose access is controlled by the licensee to
protect individuals from exposure to radiation and radioactive materials.
Title 10 Part 20 also tabulates limiting concentrations in air and water for many
radionuclides, for both the working environment and unrestricted areas, which are not to
be exceeded. For individuals in restricted areas, these concentration limits have been
calculated, based on continuing exposure for 50 years and standard physiological parame-
ters, to give doses no higher than either those specified above or 15 rem per year to non-
specified organs of the body.
For unrestricted areas, standards specify that no individual should receive a dose to
the whole body in any one calendar year in excess of 0.5 rem, although some exceptions based
on primary concurrent limits (see 10 CFR 20.105) do allow higher doses. In addition, the
average dose from all modes of exposure to "a suitable sample of an exposed population
group" should not exceed one-third of the limiting dose criteria. Concentration Guides for
air and water in unrestricted areas are based on limits of the resultant annual dose to
individuals (to either the whole body or specific body organs) of not more than one-tenth
the limiting dose for restricted areas.
Since radiation protection guides for the general public are based on averages over a
period of 1 year or longer, the evaluation of long-term average exposures should include
consideration of reasonable annual occupancy factors as well as the variability of the
exposure rates.