La. Admin. Code tit. 33 § XV-1421
Averagebcf | Maximumbdf | Removablebcef | |
NORM | 5,000 dpm/100 cm2 | 15,000 dpm/100 cm2 | 1,000 dpm/100 cm2 |
a Surfaces suspected of being contaminated with alpha and beta emitting naturally occurring radionuclides shall be surveyed with detectors that respond to alpha and beta radiation. The same method shall be employed when evaluating wipe samples for removable contamination.
b As used in this table, dpm (disintegrations per minute) means the rate of emission by naturally occurring radioactive material as determined by using a ratemeter or scaler and detector appropriate for the type and energy of emissions being monitored. The detector shall be capable of responding to alpha, beta, and/or gamma radiations.
c Measurements of average contamination level shall not be averaged over more than 1 m2. For objects of less surface area, the average shall be derived for each 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 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 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 shall be wiped.
f All surveys and efficiency determinations shall be made with the detector's active surface no greater than one centimeter from the surface being surveyed, wipe being analyzed, or check source being used. A scaler shall be used when evaluating wipe samples and count times shall be sufficient to detect 10 percent of the applicable limit with 95 percent confidence that the activity would be detected.
La. Admin. Code tit. 33, § XV-1421