Frequency Based on Potential Risk of Intake

DOE-STD-1136-2004

Guide of Good Practices for Occupational Radiological Protection in Uranium Facilities

Table 5 -7. Minimum Suggested Frequencies for Routine Bioassay for Uranium(a)

FREQUENCY

SOLUBILITY

SITUATION

CLASS

URINE

FECAL

IN VIVO

Radiological

Monthly

(b)

Quarterly

Annually

Special Y

Quarterly

Annually

(b)

Annually

Chemical Toxicity

Annually (c)

D and W

Monthly

(a) From ICRP Publication , 1995.

(b) The method of analysis not usually used.

5.4.2 Frequency Based on Potential Risk of Intake

Although uranium workers are not generally considered to be at high risk of incurring intakes that

might result in CEDEs of 0.1 rem or more, any uranium worker can be considered to have the potential for

such an intake (see Section 5.3.2). However, having the potential for intake does not mean that they are

likely to incur an intake.

Workers who have the highest potential risk for an intake are those most closely working with uranium

or uranium-contaminated material. Typically, these workers are glove-box workers, maintenance workers,

and operational radiological control surveillance staff. These workers should be on a routine uranium

bioassay program, including urinalysis and in vivo measurements. Such programs are relatively insensitive

compared to the 0.1 rem CEDE monitoring threshold and are a safety net intended to catch intakes of

significance relative to regulatory limits, rather than substantially lower administrative levels. Selection of

bioassay frequency depends on the facility experience with potential intakes, the perceived likelihood of

intake, and the MDD of a program. Annual urinalyses and in vivo chest counts are fairly typical. More

frequent (e.g., semi-annual or quarterly) measurements may permit more timely review of workplace

indicators in the event that an abnormal bioassay result is obtained, but do not necessarily mean a more

sensitive program.

5.4.3 Special Bioassay as Supplements to Routine Bioassay Programs

Special bioassay programs for workers with known or suspected acute inhalation intakes of uranium or

other alpha-emitting radionuclides should include both urine and fecal sampling. Special bioassay

measurements should be initiated for each employee in a contaminated work area when surface

contamination is detected by routine surveillance if it is possible that the contamination resulted in a CEDE

of 0.1 rem or greater. Excreta samples should not be collected where they may be contaminated by external

sources of uranium. Ideally, total urine and feces should be collected for about a week

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