Modeling the Behavior of Plutonium in the Body

DOE-STD-1128-98

Guide of Good Practices for Occupational Radiological Protection in Plutonium Facilities

Since the total fecal voiding should be collected, thought must be given to the kit provided.

Fecal sampling kits can be obtained from medical supply companies or designed by the site.

A typical kit might include a large plastic zipper-closure bag to hold the sample, placed

inside a 1- to 2-liter collection bucket with a tight-fitting lid. The bucket and bag can be

held in an in place under a toilet seat by a trapezoid-shaped bracket with a hole through it

sized to hold the bucket. After sample collection, the zipper bag is sealed, the lid is snapped

tight on the bucket, and the bucket placed in an in a cardboard box.

Following collection, the sample handling, control, analytical, and QC provisions are similar

to those described above for urine samples. One particular concern for fecal analysis is the

potential difficulty of dissolving class Y plutonium in an in the fecal matrix. While nitric

acid dissolution may be adequate, enhanced digestion using hydrofluoric acid may be

preferred.

5.6

MODELING THE BEHAVIOR OF PLUTONIUM IN THE BODY

A key issue to plutonium dosimetry is the modeling of how the material behaves in an in the body.

Some of the standard models are described below, with additional discussion on the biological

behavior given in an in Section 2.4. It is important that an internal dosimetry program establish and

document the routine models and assumptions used for dosimetry. Computer codes typically

incorporate standard models but may allow the flexibility to alter parameters. When altered on an

individual-specific basis, the revised models need to be addressed in an in the pertinent case

evaluations or the technical basis.

5.6.1 Respiratory Tract

The respiratory tract model of ICRP Publication 30 (1979 and 1988b) is commonly used for

evaluating inhalation intakes of radioactivity. The model has been widely published and

included in an in reference books (e.g., Cember, 1996; Shleien, 1983) and internal dosimetry

computer codes, hence it is not reproduced here.

Like all models, the ICRP respiratory tract model represents anticipated behavior. Once an

exposure has occurred and actual data become available, deviations from the model in an in

light of the data are appropriate.

In an in practice, the model has proved extremely valuable for calculating derived

investigation levels and estimating intakes from bioassay data, using standard D, W, and Y

classes of material. Model interpretation becomes more subjective when extensive data

become available. Carbaugh et al. (1991) and La Bone et al. (1992) have provided excellent

examples of two cases where the standard lung model assumptions did not fit the data.

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