; and (B) the effects, if any, on the performance of prime contracts being supported by support contracts awarded under the authority of this section. (2) Comptroller General Not later than the end of the fifth year of operation of the authority under this section, the Comptroller General of the United States shall review the report of the Secretary under paragraph (1) for sufficiency and provide such recommendations in a report to the Committees on Armed Services of the Senate and the House of Representatives as the Comptroller General considers appropriate. (g) Sunset The authority to enter into contracts under the authority of this section shall expire six years after the date of the enactment of this Act. Any contracts entered into before such date shall continue in effect according to their terms. (h) F–35 participant nations defined In this section, the term F–35 participant nations means each of the following: (1) The United States. (2) The United Kingdom. (3) Italy. (4) The Netherlands. (5) The Republic of Turkey. (6) Canada. (7) Australia. (8) Denmark. (9) Norway. (10) Any additional nations given participant nation status by the Secretary of Defense with the concurrence of the Secretary of State. D Other matters 331. Updating and modernizing the Department of Defense explosives safety board (a) In general Section 172 of title 10, United States Code, is amended to read as follows: 172. Explosives safety board (a) Explosives safety risk management The Secretary of Defense, acting through a joint board composed of members as described in subsection (b), shall develop guidance for oversight of the explosives safety munitions risk management life-cycle of the production, storage, and transportation of supplies of military munitions for use of the organizations listed in section 111(b) of this title, with particular regard to keeping those supplies properly dispersed and stored and to preventing hazardous conditions from arising to endanger life and property inside or outside of storage reservations. (b)