Going with the flow
On the surface, we rarely worry about air quality. But nearly a mile below, heat, diesel exhaust, dust and radon must be managed through engineering controls.
Steve Gabriel, a science teacher at Spearfish High School began monitoring air quality on the 4850 Level in 2009. Airflow meters at the 4 Winze Wye, Governor?s Corner and the 17 Ledge drift track the velocity of the air as it flows through the drifts. Several of Gabriel?s students work with him as part of a class?some even go underground with Gabriel to check the equipment and retrieve data.
?Students get real-world experience and learn about problem solving,? Gabriel said. ?They also learn that science is an ongoing pursuit that takes time and effort.?
Radiation/Experiment Health and Safety Manager Chuck Lichtenwalner, who helps retrieve data for Gabriel, said ventilation is critical to the safety of personnel and the experiments. ?Without a good system in place, we would have high radon levels and a very hot environment.?
Fresh air travels down the Ross and Yates shafts and is pulled through the drifts by the Oro Hondo and 5 Shaft fans?air doors ensure the air gets where it is needed. Along with bringing much-needed air, the fans pull out dust, diesel exhaust and heat, and reduce radon levels.
A recent test in which both fans were shut down for a period of time proved just how important the ventilation system is, Lichtenwalner said. After a three-hour shut down, air flows to the underground dropped significantly and radon levels increased by 80 percent in the Davis Campus. After four hours, radon levels at the Ross campus increased by 200 percent. That?s acceptable for human health, but not the sensitive experiments on the 4850 Level.
?Both LUX and MAJORANA want the lowest levels of radiation they can get,? Lichtenwalner said. ?Our ventilation system is a key component in helping them achieve those levels.?
Bryce Pietzyk, Senior Underground Operations Engineer, said Gabriel?s work is critical to another major project on the 4850 Level?the Long-Baseline Neutrino Facility (LBNF). ?We will use Steve?s data to help verify that our ventilation model for LBNF is working correctly.?