DOE Order 5400.5, Ch. 2 (DOE, 1993c) also provides the following guidelines for
(1) residual concentrations of radionuclides in soil, (2) concentrations of airborne
(5) radionuclide concentrations in air or water:
-- Residual radionuclides in soil - Generic guidelines for thorium and radium
(226Ra, 228Ra, 230Th, and 232Th) are 5 pCi/g averaged over the first 15 cm of soil
below the surface and 15 pCi/g averaged over 15-cm-thick layers of soil more
than 15 cm below the surface. For other radionuclides in soil (e.g., plutonium),
specific guidelines should be derived from the basic dose limit by means of an
environmental pathway analysis using specific property data where available.
Residual concentrations of radioactive material in soil are defined as those in
excess of background concentrations averaged over an area of 100 m2.
-- Airborne radon decay products - Applicable generic guidelines are found in
40 CFR 192 (EPA, 1992b). In any occupied or habitable building, the objective
of remedial action should be, and a reasonable effort should be made to
achieve, an annual average (or equivalent) radon decay product concentration
(including background) not to exceed 0.02 WL. Remedial actions by DOE are
not required to comply with this guideline when there is reasonable assurance
that residual radioactive material is not the source of the radon concentration.
-- External gamma radiation - The average level of gamma radiation inside a
building or habitable structure on a site to be released without restrictions
should not exceed the background level by more than 20 µR/h.
-- Surface contamination - The DOE guidelines on transuranic surface
contamination levels are given in a DOE memorandum dated November 17,
1995, "Application of DOE 5400.5 requirements for release and control of
property containing residual radioactive materials," the guideline values are as
20 dpm/100 cm2
Total (Fixed plus Removable Contamination)
500 dpm/100 cm2