The Nuclear Test Personnel Review (NTPR) program is a Department of Defense (DoD) program that confirms veteran participation in U.S. nuclear tests from 1945 to 1992, and the occupation forces of Hiroshima and Nagasaki, Japan.
Members of this group are sometimes referred to as atomic veterans or atomic vets.
If the veteran is a confirmed participant of these events, NTPR may provide either an actual or estimated radiation dose received by the veteran. The Department of Veterans Affairs (VA) and the Department of Justice (DOJ) will request this information from DTRA during claim reviews as required.
Source: https://www.dtra.mil/DTRA-Mission/Reference-Documents/NTPR-Info/