Tuesday evening, workers at WIPP successfully restarted the 860A fan that is part of the mine ventilation and filtration system currently operating at the site.
The 860A fan was started Feb. 14, when continuous air monitors (CAM) in the WIPP underground facility detected elevated levels of radioactive contamination and shifted the underground ventilation system into filtration mode, forcing all air exiting the facility through High Efficiency Particulate Air (HEPA) filters. The WIPP underground facility has remained in filtration mode since the event occurred.
The 860A fan ran for approximately two months following the radiological incident before being taken off-line for maintenance. Since that time, the 860B or the 860C fans have been operating to continue the air filtration process. Because the 860A fan was operational immediately following the radiological release, WIPP radiological control staff anticipated that a small amount of residual contamination could be present in the adjacent ductwork and the interior workings of the fan and that a low level of contamination could be released during the restart.
Air conditions were monitored in real time and set at conservative limits. As a precautionary measure, workers on site during the restart were required stay indoors and “shelter in place.” As anticipated, the air monitors detected slightly increased readings shortly after restarting and then fell to expected levels within a few minutes. Returning 860A fan to full service means all three 860 fans are confirmed to be reliable for operation and periodic rotation.
Air particulate filters from 16 low-volume air samplers on and around the site were exchanged prior to and again following the fan start up. These filters will be sent for analysis after the 72-hour waiting period necessary for decay of naturally occurring radon. Analysis results will be used to confirm real-time measurements from the CAM. Results are expected to be within the normal variation observed at the site and below levels that would impact public health or the environment.
The City of Carlsbad and DOE will co-host its Town Hall meeting featuring updates on WIPP recovery activities. The meeting is scheduled for 5:30 p.m., Thursday at Carlsbad City Council Chambers, 101 N. Halagueno St. Live streaming of the meeting can be seen at http://new.livestream.com/rrv/.