Radionuclide1. | Average2,3 | Maximum2,4 | Removable2,5 |
U-nat, U-235, U-238, and associated decay products | 5,000 dpm/ 100 cm2 | 15,000 dpm/ 100cm2 | 1,000 dpm/ 100 cm2 |
Transuranics, Ra-226, Ra-228, Th-230, Pa-231, Ac-227, I-125, I-129 | 100dpm/ 100cm2 | 300 dpm/ 100cm2 | 20dpm/ 100cm2 |
Th-nat, Th-232, Sr-90, Ra-223, Ra-224, U-232, I-126, I-131, I-133 | 1000 dpm/ 100cm2 | 3000 dpm/ 100cm2 | 200 dpm/ 100cm2 |
Beta-gamma (Exceptions noted above) | 5,000 dpm/ 100 cm2 | 15,000 dpm/ 100cm2 | 1,000 dpm/ 100 cm2 |
1 Where surface contamination by both alpha-and beta-gamma-emitting radionuclides exists, the limits established for alpha-and beta-gamma-emitting radionuclides apply independently.
2As 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 on an instrument calibrated for background, efficiency, and geometric factors associated with the instrumentation, in accordance with R9-7-449.
3Measurements of average contamination level shall not be averaged over more than one square meter. For objects of less surface area, the average shall be derived for each object.
4The maximum contamination level applies to an area of not more than 100 cm2.
5The amount of removable radioactive material per 100 cm2 of surface area shall 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 instrument calibrated in accordance with R9-7-449. When removable contamination on objects of surface area A (where A is less than 100 sq. cm) is determined, the entire surface shall be wiped and the contamination level multiplied by 100/A to convert to a "per 100 sq. cm" basis.
Ariz. Admin. Code tit. 9, ch. 7, art. 4, tbl. 1