Example 5.2. Criteria for Participating in Individual Monitoring Programs

DOE-STD-1121-98

Example 5.2 (Continued)

pressure suits should undergo routine bioassay or have provisions for breathing zone air sampling

within the suit.

Criterion 5:

Long-term chronic exposure to air concentrations exceeding 2% of the DAC

This condition can apply to facilities that have low-level airborne radioactivity but do not meet the

criteria for posting as airborne contamination areas. Caution: just because an area does not require

posting as an airborne contamination area (that is, 10% of the DAC) does not mean that individual

monitoring is not needed. Where routine air concentrations never exceed posting requirements but

exceed 2% of the DAC, the need for individual monitoring should be based on potential stay times in

those areas. Continuous (or significant) occupancy over a year would suggest individual monitoring

is needed.

Criterion 6:

Short-term chronic airborne exposure, or multiple acute airborne exposures

Criteria 6 and 7 may be particularly useful for addressing supervisory, walk-through, and inspection

staff who do not actually handle or process radioactive material. The derived concentration threshold

for individual monitoring (Cair, in terms of fractional DAC) can be calculated using an exposure

fraction for the worker (fw), as follows:

Criterion 7:

Tracking individual exposure in DAC-h

Individual work assignments and concentrations are tracked to determine cumulative exposure in

DAC-h. Once a worker exceeds 40 DAC-h, bioassay should be performed (if feasible). This method

implies the use of a DAC-h tracking log. Such a log might be continued for a worker over the course

of a year and then zeroed out at the start of a new year. One issue to be resolved by the facility is

what to do with DAC-h if the total never exceeds 40. For this situation, sites should still provide

intake and dose assessments based solely on DAC-h.