3/19/2011 - Tech. Sgt. Michael Welles is checked for radiation exposure March 13, 2011, at Yokota Air Base, Japan, after a flight to northern Japan. A team of bioenvironmental engineers from the 374th Aerospace Medicine Squadron and emergency managers from the 374th Civil Engineer Squadron were checking returning aircrew members. Sergeant Welles is assigned to the 33rd Rescue Squadron. (U.S. Air Force photo/Staff Sgt. Samuel Morse)

3/19/2011 - A member of a post-mission assessment team uses a radiation meter March 13, 2011, to screen aircraft and aircrew members returning to Yokota Air Base, Japan, from a flight to northern Japan. The team is composed of experts from the 374th Aerospace Medicine Squadron's bioenvironmental engineering flight and the 374th Civil Engineer Squadron's emergency management flight. (U.S. Air Force photo/Staff Sgt. Samuel Morse)

3/19/2011 - Members of a post-mission assessment team screen aircraft and aircrew members March 13, 2011, returning to Yokota Air Base Japan, from a flight to northern Japan. The team is composed of experts from the 374th Aerospace Medicine Squadron's bioenvironmental engineering flight and the 374th Civil Engineer Squadron's emergency management flight. (U.S. Air Force photo/Staff Sgt. Samuel Morse)

3/19/2011 - Senior Airman Daniel Burdick, 18th Aerospace Medicine Squadron, uses a AMD 300 radiation survey meter to scan Staff Sgt. Aaron Wermy, 374 Aircraft Maintenance Squadron, March 21. The ADM 300 is used to scan aircraft and personnel for possible presence of radiation exposure. (U.S. Air Force photo/Staff Sgt. Jonathan Steffen)

3/19/2011 - Senior Airman Daniel Burdick, 18th Aerospace Medicine Squadron, and Senior Airman Eva Gaus, 374th Civil Engineer Squadron, scan for possible presence of radiation exposure on a C-17 Globemaster III here March 21. The Airmen screened the aircraft and aircrew members upon return from a flight to northern Japan. (U.S. Air Force photo/Staff Sgt. Jonathan Steffen)

3/19/2011 - Senior Airman Daniel Burdick, 18th Aerospace Medicine Squadron, and Senior Airman Eva Gaus, 374th Civil Engineer Squadron, scan for possible presence of radiation exposure on a C-17 Globemaster III here March 21. The Airmen screened the aircraft and aircrew members upon return from a flight to northern Japan. (U.S. Air Force photo/Staff Sgt. Jonathan Steffen)