Table 5 -5. Minimum Uranium Bioassay Monitoring(a,b)

DOE-STD-1136-2004

_ Guide of Good Practices for Occupational Radiological Protection in Uranium Facilitie s

Table 5 -5. Minimum Uranium Bioassay Monitoring(a,b)

ACTIVITY AMOUNT (c)

TYPES OF OPERATION

MASS

Processes in open room on bench

0.5 kg(d)

320 Ci

top, with possible escape from

process vessels

Process with possible escape of

uranium that are carried out within a

5 kg

3,200 Ci

fume hood of adequate design, face

velocity, and performance reliability

Process carried out within

gloveboxes that are ordinarily

closed, but with possible release

50 kg

32,000 Ci

from process vessels and occasional

exposure to contaminated box and

leakage

(a) From ANSI/HPS 1995.

(b) Values chosen as conservative for any transportability class or mixture of isotopes of uranium.

For a particular type of operation, the value of mass or activity that is more restrictive for the

mixture should be used.

235

U (see Appendix A.2 of ANSI/HPS 1995).

(d) From ANSI/HPS 1995, Appendix A.1.

5.3.3

Selection of Bioassay Monitoring Techniques

Bioassay monitoring techniques fall into two broad categories: direct measurement of radioactive

materials in the body (in vivo counting) and analysis of material removed from the body for laboratory (in

vitro analysis). In vivo counting includes measurements of the chest, lung, skeleton, liver, and wounds. In

vitro measurements include urinalysis, fecal analysis, and occasionally analysis of tissue, sputum, or

blood samples. Methods for in vitro analysis include liquid scintillation counting, fluorescence

measurements, gamma spectrometry, chemical separation followed by electrodeposition, and counting

with radiation detectors. A brief overview of bioassay techniques and capabilities has been developed

(Selby et al. 1994). Further discussion of the techniques is provided below.

In addition, to ensure that adverse chemical toxicity effects are unlikely, bioassays for uranium

should be performed when intakes of 1 mg or more of soluble uranium are likely to occur in any one

work day (ANSI/HPS 1995).

5.3.3.1 In Vivo Counting

Direct bioassay (in vivo counting) is the measurement of radiations emitted from radioactive

material taken into and deposited in the body. Direct bioassay is appropriate for detection and

measurement of photons emitted by uranium and its decay products. Lung, wound, and skeleton

counting are examples of in vivo monitoring most commonly used for uranium and its progeny.

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