
ACCEPTABLE SURFACE CONTAMINATION LEVELS     NUCLIDES A  AVERAGE B C F  MAXIMUM B D F  REMOVABLE B E F WIPE LIMITS  Unat, U235, U238, and associated decay products  5,000 dpm/100 cm2  15,000 dpm/100 cm2  1,000 dpm α/100 cm2  Transuranics, Ra226, Ra228, Th230, Th228, Pa231, Ac227, I125, I129  100 dpm/100 cm2  300 dpm/100 cm2  20 dpm/100 cm2  Thnat, Th232, Sr90, Ra223, Ra224, U232, I126, I131, I133  1000 dpm/100 cm2  3000 dpm/100 cm2  200 dpm/100 cm2  Betagamma emitters (nuclides with decay modes other than alpha emission or spontaneous fission) except SR90 and others noted above  5000 dpm/100 cm2  15,000 dpm/100 cm2  1000 dpm βγ/100 cm2   
  A  Where surface contamination by both alpha and betagammaemitting nuclides exists, the limits established for alphaand betagammaemitting nuclides should apply independently.  B  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.  C  Measurements of average contaminant should not be averaged over more than 1 square meter. For objects of less surface area, the average should be derived for each such object.  D  The maximum contamination level applies to an area of not more than 100 cm2.  E  The amount of removable radioactive material per 100 cm2 of surface area should be determined by wiping that area with dry filter or soft absorbent paper, applying moderate pressure, and assessing the amount of radioactive material on the wipe with an appropriate instrument of known efficiency. When removable contamination on objects of less surface area is determined, the pertinent levels should be reduced proportionally and the entire surface should be wiped.  F  The average and maximum radiation levels associated with surface contamination resulting from betagamma emitters should not exceed 0.2 mrad/hr at 1 cm and 1.0 mrad/hr at 1 cm, respectively, measured through not more than 7 milligrams per square centimeter of total absorber. 
[Statutory Authority: RCW 70.98.050 and 70.98.080. WSR 0906003, § 246232140, filed 2/18/09, effective 3/21/09. Statutory Authority: RCW 43.70.040. WSR 9102049 (Order 121), recodified as § 246232140, filed 12/27/90, effective 1/31/91. Statutory Authority: RCW 70.98.080. WSR 8701031 (Order 2450), § 40219590, filed 12/11/86; WSR 8319050 (Order 2026), § 40219590, filed 9/16/83.]
