The FIRST Act establishes the Foundational Infrastructure for Responsible Use of Small Modular Reactor Technology (FIRST) program within the Department of State. Managed by the Under Secretary for Arms Control and International Security, this program is designed to promote the responsible international deployment of civil nuclear energy, specifically small modular reactors. Its primary goals include benefiting United States economic and national security interests by advocating for U.S. businesses and their nuclear technologies abroad. The program's functions involve engaging in diplomacy with partner governments to prioritize the highest safety, security, and nonproliferation standards for civil nuclear reactor deployment. It will also provide consultation on best practices for licensing, legal, and regulatory frameworks for adopting U.S. nuclear infrastructure. Furthermore, FIRST offers early-stage commercial project development support, including feasibility studies and workforce development, and fosters cooperation with partner countries on training and technical resource sharing to facilitate small modular reactor fleet deployment. The Act also mandates regular reports and briefings to Congress on the program's implementation and activities, with the program set to terminate on June 8, 2034.