| NUCLIDES A |
AVERAGE B C F |
MAXIMUM B D F |
REMOVABLE B E F
WIPE LIMITS
|
| U-nat, U-235, U-238, and
associated decay products |
5,000 dpm/100 cm2 |
15,000 dpm/100 cm2 |
1,000 dpm α/100 cm2 |
| Transuranics, Ra-226, Ra-228,
Th-230, Th-228, Pa-231, Ac-227,
I-125, I-129 |
100 dpm/100 cm2 |
300 dpm/100 cm2 |
20 dpm/100 cm2 |
| Th-nat, Th-232, Sr-90, Ra-223,
Ra-224, U-232, I-126, I-131, I-133 |
1000 dpm/100 cm2 |
3000 dpm/100 cm2 |
200 dpm/100 cm2 |
| Beta-gamma emitters (nuclides
with decay modes other than
alpha emission or spontaneous
fission) except SR-90 and
others noted above |
5000 dpm/100 cm2 |
15,000 dpm/100 cm2 |
1000 dpm &bgr;&ggr;/100 cm2 |
|
|
| A |
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. |
| 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 beta-gamma 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. |