Farok Sharif, President and Project Manager of Nuclear Waste Partnership (the WIPP management and operating contractor) said, “Biological testing continues on other workers who were at the site following the initial exposure event, and there is always the possibility of positive exposure results from that testing. The ability to detect extremely small amounts of radioactive material also means there may be false positives that occur throughout the testing process.”
Air and environmental monitoring around the WIPP site, both by site contractors and by the Carlsbad Environmental Monitoring and Research Center (CEMRC), at New Mexico State University, show alpha and beta emissions have decreased and are now close to background levels.
This results have not yet been posted on the WIPP website which still just has the preliminary data posted on the 18th.
Here is the data from Carlsbad Environmental Monitoring and Research Center (CEMRC),
|Station A, operated by NMSU CEMRC, to monitor air exiting the WIPP underground. Upper right: photo of the 14-foot diameter air exhaust shaft as it emerges from the underground and turns horizontal. The Station A building sits over the turn and continuously subsamples the exhaust air. Upper left: schematic of sampling set-up showing the three probes that subsample the exhaust air. Lower left: photo of Station A interior. Lower right: Photo of two of the four huge blowers that drive the exhaust, each one capable of over 100,000 cubic feet per minute air flow. The exhaust shaft is seen disappearing into the filter building where Station B sits. Source: CEMRC - via Forbes online|
Only essential personnel have been allowed access to the site since the event. Upon leaving the site, each individual is checked for any external contamination.