APPENDIX C TO PART 835-DERIVED AIR CONCENTRATION (DAC) FOR WORKERS APPENDIX D TO PART 835-SURFACE RADIOACTIVITY VALUES
Surface Radioactivity Values;{1}in dpm/100 cm^2 ------------------------------------------------------------------------------ | Removable | Total (Fixed Nuclide | {2,4} | + Removable) | | {2,3} ------------------------------------------------------------------------------ | | U-nat, U-235, U-238, and associated decay | 1,000 | 5,000 products. | | Transuranics, Ra-226, Ra-228, Th-230, Th- | 20 | 500 228, Pa-231, Ac-227, I-125, I-129. | | Th-nat, Th-232, Sr-90, Ra-223, Ra-224, U- | 200 | 1,000 232, I-126, I-131, I-133. | | Beta-gamma emitters (nuclides with decay | 1,000 | 5,000 modes other than alpha emission or | | spontaneous fission) except Sr-90 and | | others noted above.{5} | | Tritium Organic Compounds; surfaces | [Reserved] | [Reserved] contaminated by HT, HTO, and metal tritide | | aerosols. | | ------------------------------------------------------------------------------ {1}The values in this appendix apply to radioactive contamination deposited on, but not incorporated into the interior of, the contaminated item. Where surface contamination by both alpha- and beta-gamma-emitting nuclides exists, the limits established for alpha- and beta-gamma-emitting nuclides should apply independently. {2}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. {3}The levels may be averaged over one square meter provided the maximum surface activity in any area of 100 cm 2 is less than three times the value specified. For purposes of averaging, any square meter of surface shall be considered to be above the activity guide G if: (1) From measurements of a representative number n of sections it is determined that 1/n Sigma n S i >= G, where S i is the dpm/100 cm 2 determined from measurement of section i; or (2) it is determined that the sum of the activity of all isolated spots or particles in any 100 cm 2 area exceeds 3G. {4}The amount of removable radioactive material per 100 cm 2 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 cm 2 is determined, the activity per unit area should be based on the actual area and the entire surface should be wiped. Except for transuranics and Ra-228, Ac-227, Th-228, Th-230, Pa-231 and alpha emitters, 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. {5}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 enriched.
APPENDIX E TO PART 835-[RESERVED]