Supposedly a small nuclear reactor was used for the drilling, Raytheon was the contractor, and there was some sort of accident with employees having to be medevacuated due to radiation exposure.
That, anyway, is all I've been able to glean from different sources because our government has tightened up on candid information like a bull's anus in fly season.
Evacuation from Vostok.
Could've done without that image.