; and (2) by striking not more than 600 . (b) Conforming amendments Such section is further amended— (1) in the section heading, by striking Authority to establish and inserting Establishment of ; and (2) in the second sentence, by striking Subject to the limitations in the preceding sentence, the authority and inserting The authority . (c) Clerical amendment The table of contents for the National Nuclear Security Administration Act is amended by striking the item relating to section 3241 and inserting the following new item: Sec. 3241. Establishment of contracting, program management, scientific, engineering, and technical positions. . 3114. Prohibition on use of laboratory-directed research and development funds for general and administrative overhead costs Section 4811 of the Atomic Energy Defense Act ( 50 U.S.C. 2791 ) is amended— (1) by redesignating subsection (d) as subsection (e); and (2) by inserting after subsection (c) the following new subsection (d): (d) Funds provided to a national security laboratory or nuclear weapons production facility for laboratory-directed research and development may not be used to cover the costs of general and administrative overhead for the laboratory or facility. . 3115. Prohibition on use of funds for advanced naval nuclear fuel system based on low-enriched uranium None of the funds authorized to be appropriated for the National Nuclear Security Administration for fiscal year 2020 or any fiscal year thereafter may be obligated or expended to conduct research and development of an advanced naval nuclear fuel system based on low-enriched uranium until the following certifications are submitted to the congressional defense committees: (1) A joint certification of the Secretary of Energy and the Secretary of Defense that the determination made by the Secretary of Energy and the Secretary of the Navy pursuant to section 3118(c)(1) of the National Defense Authorization Act for Fiscal Year 2016 ( Public Law 114–92