Example 5.4. Criteria for Commencing Special Bioassay

DOE-STD-1121-98

Example 5.4. Criteria for Commencing Special Bioassay

Special bioassay should be initiated if any of the following criteria are met (Fauth et al. 1996,

Carbaugh et al. 1994a):

Nasal or mouth smears, nose blows, or sputum samples that indicate above background levels

Any contaminated wound

Contamination on protective clothing in excess of 10,000 dpm-alpha or 100,000 dpm-

beta/gamma per 100 cm2 if no respiratory protection is in use

Unplanned spread of contamination on accessible surfaces in excess of 1500 dpm-alpha or

15,000 dpm-beta/gamma per 100 cm2 if no respiratory protection is in use

Any detectable general facial contamination in excess of 200 dpm-alpha or 4,000 dpm-

beta/gamma per 100 cm2

Detectable contamination on the skin, other than the facial area, in excess of 1000 dpm-alpha

or 100,000 dpm-beta/gamma per 100 cm2

Detectable contamination inside a respirator after its removal

Acute exposure to 40 DAC-h after incorporating any respiratory protection factor

Any unplanned suspected intake

that no further potential for intake existed, then an employment termination bioassay is probably not

needed. For practical purposes, the ending-task measurement may be considered the release of a worker

from requirements for further bioassay.

5.6 BIOASSAY FOR DECLARED PREGNANT FEMALE WORKER

DOE has published an implementation guide on Evaluation and Control of Radiation Dose to the

Embryo/Fetus Guide (DOE 1999a). All relevant parts of this document should be used in design and

operation of the parts of a bioassay program that apply to declared pregnant female workers. This

Technical Standard does not summarize the recommendations of that implementation guide but does note

a few points about internal dosimetry. The dose limits for a declared pregnant worker's embryo-fetus is

substantially more restrictive than those for radiological workers, except for the fact that the 500-mrem

limit applies to the dose equivalent for the nine-month gestation period, and not the committed dose

equivalent for 50 years following intake. The maternal uptakes that would cause a 500-mrem gestation

period dose to the embryo-fetus are in the nominal microcurie range (e.g., approximately 1 :Ci for 238Pu,

10 :Ci for 137Cs, and 50 :Ci for 90Sr, based on Fauth et al. 1996). Routine bioassay programs designed

to monitor workers should be easily adequate to demonstrate compliance with the embryo-fetus dose

limits. As a verification, it may be desirable to obtain a special bioassay upon receipt of a pregnancy