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DOE-HDBK-1129-99
D.2 "Response to Questions and Clarification of Requirements and Processes:
DOE 5400.5, Section II.5 and Chapter IV Implementation (Requirements Relating
to Residual Radioactive Materials)", dated November 17, 1995, DOE, Office of
Assistant Secretary for Environmental, Safety and Health Office of Environment
TABLE 1 SURFACE ACTIVITY GUIDELINES
Allowable Total Residual Surface Activity (dpm/100 cm2)4
Radionuclides5
Average6/7  Maximum9/
Removable9
8
Group 1 Transuranics, I-125, I-129, Ac-227, Ra-226,
100
300
20
Ra-228, Th-228, Th-230, Pa-231
Group 2 Th-natural, Sr-90, I-126, I-131, I-133, Ra-
1,000
3,000
200
223, Ra-224, U-232, Th-232
Group 3 U-natural, U-235, U-238, and associated
5,000
15,000
1,000
decay products, alpha emitters
Group 4 Beta-gamma emitters (radionuclides with
5,000
15,000
1,000
decay modes other than alpha emission or
spontaneous10 fission) except Sr-90 and others noted
above7
Tritium (applicable to surface and subsurface)11
N/A
N/A
10,000
4
As used in this table, dpm (disintegrations per minute) means the rate of emission by radioactive material as
determined by counts per minute measured by an appropriate detector for background, efficiency, and
geometric factors associated with the instrumentation.
5
Where surface contamination by both alpha- and beta-gamma-emitting radionuclides exists, the limits
established for alpha- and beta-gamma-emitting radionuclides should apply independently.
6
Measurements of average contamination should not be averaged over an area of more than 1 m2. For
objects of smaller surface area, the average should be derived for each such object.
7
The average and maximum dose rates associated with surface contamination resulting from beta-gamma
emitters should not exceed 0.2 mrad/h and 1.0 mrad/h, respectively, at 1 cm.
8
The maximum contamination level applies to an area of not more than 100 cm2.
9
The amount of removable material per 100 cm2 of surface area should be determined by wiping an area of
that size with dry filter or soft absorbent paper, applying moderate pressure, and measuring the amount of
radioactive material on the wiping with an appropriate instrument of known efficiency. When removable
contamination on objects of surface area less than 100 cm2 is determined, the activity per unit area should
be based on the actual area, and the entire surface should be wiped. It is not necessary to use wiping
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.
10
This category of radionuclides includes mixed fission products, including the Sr-90 that is present in them. It
does not apply to Sr-90 that has been separated from the other fission products or mixtures where the Sr-90
has been enriched.
11
Property recently exposed or decontaminated should have measurements (smears) at regular time intervals
to ensure that there is not a build-up of contamination over time. Because tritium typically penetrates
material it contacts, the surface guidelines in Group 4 are not applicable to tritium. The Department has
reviewed the analysis conducted by the DOE Tritium Surface Contamination Limits Committee
("Recommended Tritium Surface Contamination Release Guides," February 1991), and has assessed
potential doses associated with the release of property containing residual tritium. The Department
recommends the use of the stated guideline as an interim value for removable tritium. Measurements
demonstrating compliance of the removable fraction of tritium on surfaces with this guideline are acceptable
to ensure that non-removable fractions and residual tritium in mass will not cause exposures that exceed
DOE dose limits and constraints.
D-2


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