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Q Clearance
A Q Access Authorization, or Q Clearance, is equivalent to a U.S. Department of Defense Top Secret clearance.
Anyone possessing an active Q clearance is always categorized as holding a National Security Critical-Sensitive position (sensitivity Level 3).
Most Q-cleared incumbents will have collateral responsibilities designating them as Level 4: National Security Special-Sensitive personnel.
With these two designations standing as the highest-risk sensitivity levels, occupants of these positions hold extraordinary accountability, having the potential to cause "exceptionally grave" or "inestimable" damage to the national security of the United States.

Q Access Authorization means an access authorization granted by the Commission normally based on a Tier 5 (T5) investigation conducted by the Defense Counterintelligence and Security Agency, the FBI, or other U.S. Government agency that conducts personnel security investigations.
Employee Accesses Authorized Based on DOE-Issued Security Clearances
"Q" access authorization permits an individual access on a need-to-know basis to: 1. Secret and Confidential Restricted Data 2. Secret and Confidential National Security Information including intelligence information, CRYPTO (i.e., cryptographic information) or other classified communications security (COMSEC) information.
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