Monitoring Requirements and Selection of Employees

DOE-STD-1136-2004

__ Guide of Good Practices for Occupational Radiological Protection in Uranium Facilities

Bioassay classification is important because the purpose of a sample may affect the collection and

analysis or monitoring method chosen. For example, single -void urine samples are not adequate for

routine monitoring of potential uranium exposure, but can provide important information for dose-

reduction therapy following a suspected intake; samples representative of excretion over a 24-hour

period should be collected for quantitative intake and dose assessment. The date of sample collection

(and possibly the time of collection) can be very important to special monitoring performed to assess

intake. However, these are much less important with regard to periodic monitoring, for which

measurements are not expected to show detectable activity and when any detection whatsoever is likely

to initiate investigation and special bioassay.

5.3.2 Monitoring Requirements and Selection of Employees

Workers who are considered likely to have intakes resulting in excess of 0.1 rem CEDE are required

to participate in a bioassay program. The workers at highest risk of incurring an intake are the ones in

closest contact with the material. Typically, these are the operators, maintenance, and radiological control

personnel handling uranium or uranium-contaminated objects in the course of routine glove-box,

maintenance, or decommissioning operations. In the event of containment system failure, it is these

workers who will most likely incur exposure and subsequent intake. These workers should be on a routine

bioassay program designed to meet the requirements of 10 CFR 835 as a kind of safety net to identify

intakes whic h might have gone undetected by workplace monitoring.

Other workers (e.g., supervisors, inspectors, observers, guards, and tour groups) who work in or

visit a uranium facility but are not directly working with the material or contaminated objects are

normally at a substantially lower risk for incurring an intake. Although these people may not need to be

on a routine bioassay program, they should be subject to participation in a special bioassay program if

workplace indications suggest loss of control or containment.

Routine bioassay monitoring should be implemented whenever quantities of uranium handled

exceed the respective quantities in Table 5-5.

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