(Fixed + Removable) 2,3
U-nat, U-235, U-238, and associated decay products
Transuranics, Ra-226, Ra-228, Th-230,
Th-228, Pa-231, Ac-227, I-125, I-129
Th-nat, Th-232, Sr-90, Ra-223, Ra-224, U-232, I-126, I-
Beta-gamma emitters (nuclides with decay modes other
than alpha emission or spontaneous fission) except Sr-
90 and others noted above5
Tritium and tritiated compounds6
The values in this appendix, with the exception noted in footnote 5 below, apply to radioactive contamination
deposited on, but not incorporated into the interior or matrix of, the contaminated item. Where surface contamination
by both alpha- and beta gamma-emitting nuclides exist, the limits established for alpha- and beta-gamma-emitting
nuclides apply independently.
As used in this table, dpm (disintegrations per minute) means the rate of emission by radioactive material as
determined by correcting the counts per minute observed by an appropriate detector for background, efficiency, and
geometric factors associated with the instrumentation.
The levels may be averaged over one square meter provided the maximum surface activity in any area of 100 cm2 is
less than three times the value specified. For purposes of averaging, any square meter of surface shall be considered to
be above the surface contamination value if: (1) from measurements of a representative number of sections it is
determined that the average contamination level exceeds the applicable value; or (2) it is determined that the sum of the
activity of all isolated spots or particles in any 100 cm2 area exceeds three times the applicable value.
The amount of removable radioactive material per 100 cm2 of surface area should be determined by swiping the area
with dry filter or soft absorbent paper, applying moderate pressure, and then assessing the amount of radioactive
material on the swipe with an appropriate instrument of known efficiency. (Note - The use of dry material may not be
appropriate for tritium.) When removable contamination on objects of surface area less than 100 cm2 is determined, the
activity per unit area shall be based on the actual area and the entire surface shall be wiped. It is not necessary to use
swiping techniques to measure removable contamination levels if direct scan surveys indicate that the total residual
surface contamination levels are within the limits for removable contamination.
This category of radionuclides includes mixed fission products, including the Sr-90 which is present in them. It does
not apply to Sr-90 which has been separated from the other fission products or mixtures where the Sr-90 has been
Tritium contamination may diffuse into the volume or matrix of materials. Evaluation of surface contamination shall
consider the extent to which such contamination may migrate to the surface in order to ensure the surface
contamination value provided in this appendix is not exceeded. Once this contamination migrates to the surface, it may
be removable, not fixed; therefore, a "Total" value does not apply.
4.1.4 Uncertainties and Limitations
Because plutonium is relatively difficult to detect and quantify, it is important to
consider the uncertainty in the measurements when designing a plutonium
monitoring program. Although the design objective of the facility will likely be no
airborne plutonium contamination, the reality will be a measurement that ensures
airborne plutonium is below an acceptable lower limit of detection. The sampling and
monitoring program will need to be designed not only for prompt detection of