This bill requires the Administrator for Nuclear Security to develop a comprehensive plan within 90 days of enactment to modernize the nuclear security enterprise. The plan must focus on two key areas: accelerating and modernizing Material Staging Capabilities to replace outdated facilities, including detailed phases and cost estimates, and accelerating near-term Critical Decisions milestones for fiscal year 2026. The Administrator is directed to execute this plan concurrently with ongoing infrastructure modernization efforts for high explosives capabilities, specifically mentioning the continued construction of the High Explosives Synthesis Formulation and Production facility. Furthermore, the bill mandates that the Administrator brief the appropriate congressional committees on the Material Staging Capabilities plan within 180 days. These committees include the Armed Services and Appropriations committees of both the Senate and the House of Representatives, ensuring legislative oversight of the modernization efforts.