Q clearance or
Q access authorization is the
Department of Energy (DOE) security clearance required to access
Top Secret Restricted Data,
Formerly Restricted Data, and National Security Information, as well as Secret Restricted Data. Restricted Data (RD) is defined in the
Atomic Energy Act of 1954 and covers nuclear weapons and related materials. The lower-level
L clearance is sufficient for access to Secret Formerly Restricted Data (FRD) and National Security Information, as well as Confidential Restricted Data, Formerly Restricted Data, and National Security Information.
[1][2] Access to Restricted Data is only granted on a
need-to-know basis to personnel with appropriate clearances.