In Vivo Monitoring - doe-std-1136-20040120

DOE-STD-1136-2004

Guide of Good Practices for Occupational Radiological Protection in Uranium Facilities

staff selection, qualification, and training,

total CEDE from all intakes during a year,

committed dose equivalent (CDE) to organs or tissues of concern from all intakes during a year,

magnitude of intake for each radionuclide during a year,

data necessary to allow subsequent verification, correction, or recalculation of doses, and

gestation period dose equivalent to the embryo/fetus from intake by the mother during the entire

gestation period.

Recommendations for testing criteria for radiobioassay laboratories are in ANSI N13.30. These

recommendations include calculational methods and performance criteria for bias, precision, and testing

levels. The establishment of minimum detection capability must be driven by programmatic needs, ideally

related to some concept of a minimum detectable dose, rather than as a single magnitude number.

Some sites have established brief flyers or brochures describing their bioassay measurements.

These may be distributed to workers during classroom training, upon notification of scheduled

measurements, or at the time of the measurement or sample.

The choice of the measurement technique, or of a combination of techniques, depends on the

radioisotopes, physicochemical forms, and exposure pathway.

Because of the wide range of chemical and physical forms of uranium, an appropriate bioassay

program is one that does not rely on assumed transportability and will provide data from which radiation

dose can be calculated that will not be dependent on the chemical form. This will normally require both in

vivo and in vitro bioassay. If the uranium being handled has been shown to be of medium to high

transportability, then the bioassay program must be designed to demonstrate that 3 g U/g kidney has not

been exceeded.

Uranium class Y materials cannot be effectively detected at the levels listed in ICRP Publication 54 by

ordinary methods available for either lung in vivo counts or urinalysis. This is shown by the fact that the

DIL (based on 0.3 ALI as per ANSI/HPS 1995) was 0.06 pCi L-1, which is below the MDA suggested as

reasonable for routine uranium alpha urinalysis (0.1 pCi L-1) in the standard.

5.5.1 In Vivo Monitoring

The scheduling and measurement process for obtaining in vivo measurements is usually

straightforward. Workers are scheduled for the measurements and results are available shortly after the

measurement is completed. The long counting times can impose limitations on the throughput of workers

through a measurement facility, making scheduling an important issue. Procedures should be in place to

ensure that workers arrive for scheduled measurements and that follow-up occurs when a measurement is

not completed or a worker fails to show.

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