; 5 U.S.C. app.), and without regard to any provision of title 5 (except sections 3303 and 3328), United States Code, governing appointments in the civil service, if the Chairman of the Nuclear Regulatory Commission (in this section referred to as the Chairman ) issues or renews a certification that there is a severe shortage of candidates or a critical hiring need for covered positions to carry out the Nuclear Regulatory Commission’s (in this section referred to as the Commission ) responsibilities and activities in a timely, efficient, and effective manner, the Chairman may, during any period when such a certification is in effect— (A) recruit and directly appoint highly qualified individuals into the excepted service for covered positions; and (B) establish in the excepted service term-limited covered positions and recruit and directly appoint highly qualified individuals into such term-limited covered positions, which may not exceed a term of 4 years. (2) Limitations (A) Merit principles To the maximum extent practicable, any action authorized pursuant to paragraph (1) shall be consistent with the merit principles of section 2301 of title 5, United States Code. (B) Number The number of highly qualified individuals serving in— (i) covered positions pursuant to paragraph (1)(A) may not exceed 210 at any one time