Which of the following is NOT a requirement for a Trusted Personnel Certification (TPC)?

The correct choice indicates that having a TS (Top Secret) security clearance is not a requirement for Trusted Personnel Certification (TPC). While security clearances are vital for individuals working with classified information or within sensitive areas, the TPC specifically focuses on ensuring personnel meet certain qualifications and training related to nuclear surety.

The other requirements indicate a broader scope necessary for TPC. Completing nuclear surety training ensures that personnel understand the principles and practices surrounding nuclear safety and control. Designation to perform a specific task affirms that the individual has a defined role within the system, contributing to operational security. Knowledge of nuclear surety requirements is critical as it encompasses the fundamental practices and regulations that govern nuclear safety.

Thus, even though a DC (Department of Defense) security clearance might be needed for certain roles, it is not a prerequisite for being certified as trusted personnel under the specific criteria of TPC.