; and (iii) in a case in which a successor to a member has not been appointed as of the date of expiration of the member’s term, the member may serve for an additional 1-year period, beginning on the day after the date of expiration of the member’s term, or until a successor has been appointed under paragraph (1), whichever occurs first. (C) Vacancies The Secretary shall fill any vacancy to the Board in the manner in which the original appointment was made. Any member appointed to fill a vacancy on the Board occurring before the expiration of the term for which the member’s predecessor was appointed shall be appointed only for the remainder of that term. (D) Conflict of interest A voting member of the Board shall be considered a special Government employee for the purposes of chapter 131 of title 5, United States Code. (5) Chair (A) In general The Board shall elect a Chair from among the members of the Board through a majority vote of a quorum. (B) Term The Chair shall serve in such role for a term of 2 years, and may be re-elected in accordance with subparagraph (A). (C) Chair vacancy If the chair has been vacant for more than 3 months, at the written request of a quorum of the Board, the Director shall convene a meeting of the Board to, at a minimum, elect a chair. (6) Compensation Members of the Board shall serve without pay for such service. Members of the Board who are officers or employees of the United States may not receive additional pay, allowances, or benefits by reason of their service on the Board. (7) Travel expenses The members of the Board shall receive travel expenses, including per diem in lieu of subsistence, in accordance with subchapter I of chapter 57 of title 5, United States Code. (8) Powers of the board (A) In general In the exercise of its duties under subsection (b) and in accordance with chapter 10 of title 5, United States Code, the Board shall be independent of the Director and the other offices and officers of the Institute. (B) Executive director The Board shall have an Executive