Use of Engineering Controls for Management of Exposures to Radon, Thoron

DOE-STD-1121-98

determined by reference to standards traceable to the National Institute of Standards and Technology, if

such standards are available.

Periodic functional tests should be performed at a frequency dependent on the performance history

of the instrument. As a minimum, these tests will include checks of the airflow rate and detector

efficiency. Replicate pairs of measurements should also be performed on a rotating schedule that covers

all instruments at least once every two months.

4.5.6 Use of Engineering Controls for Management of Exposures to Radon, Thoron, and

Their Short-Lived Decay Products

The use of engineering control methods for radon and thoron should be based on cost-benefit

analyses because they can be expensive to implement. Engineering controls for new building

construction may be significantly cheaper than for existing construction. Guidance and model standards

are available from the U.S. Environmental Protection Agency for reducing radon levels in existing

construction (EPA 1989, 1991a, 1992, 1993, 1994b, 1994c). Such methods may be appropriate when the

radon is due to DOE "activities" as defined in 10 CFR 835. Engineering controls for contaminated sites

with elevated radon levels due to DOE activities may not be cost-effective, and personnel protective

equipment or other radiation protection measures such as limiting stay times, performing work at times of

the day when radon progeny levels are lower, etc., may be needed.

All new construction at DOE facilities that will be occupied for significant periods of time should be

"radon-resistant" construction. References for radon-resistant construction methods are available from

the U.S. Environmental Protection Agency and ASTM (EPA 1991b, 1994a; ASTM 1992). Making new

structures radon-resistant generally adds little to the cost of construction.