; or (ii) a covert test under paragraph (3)(B)(i), means any individual who the cover team monitoring such test determines needs to know the identity of such cover team. (B) Covered employee The term covered employee means any individual who receives notice of a covert test before the completion of a test under paragraph (2)(B). (C) Covert test (i) In general The term covert test means an exercise or activity conducted by a covert testing office, the Inspector General of the Department of Homeland Security, or the Government Accountability Office to intentionally test, compromise, or circumvent transportation security systems to identify vulnerabilities in such systems. (ii) Limitation Notwithstanding clause (i), the term covert test does not mean an exercise or activity by an employee or contractor of the Transportation Security Administration to test or assess compliance with relevant regulations. (D) Covert testing office The term covert testing office means any office of the Transportation Security Administration designated by the Administrator of the Transportation Security Administration to conduct covert tests of transportation security systems. (E) Employee of a covert testing office The term employee of a covert testing office means an individual who is an employee of a covert testing office or a contractor or an employee of a contractor of a covert testing office. . 513. Explosive detection technology The Secretary of Homeland Security shall prioritize the research and facilitation of next generation technologies to detect explosives in the Nation’s surface transportation systems. 514. Recurrent vetting for surface transportation credential-holders Section 70105 of title 46, United States Code, is amended by adding at the end the following new subsection: (r) Recurrent vetting (1) In general Not later than 180 days after the date of the enactment of this subsection, the Secretary shall develop and implement a plan to utilize the Federal Bureau of Investigation’s Rap Back Service in order to establish