The objective of this task was to investigate the availability and suitability of some novel materials and methods of construction for air-restraining bulkheads for use in confining radon-rich air in unused sections of underground uranium mines. Two preferred systems of bulkhead construction were proposed, based on a search of commercially available materials, and were successfully tested in an operating commercial mine in Lasal, Utah. Both systems were found to be generally satisfactory under the conditions of the 5-month-long test. As an auxiliary aid to prevent leakage of radon-polluted air from the bulkhead area, a servocontrolled exhaust system was designed to maintain a favorable atmospheric-pressure gradient relative to the rest of the mine. A radon-scavenging system, based on adsorption on activated charcoal, was also designed and successfully tested for use in connection with the pressure- balancing exhaust unit.