The Advanced Nuclear Support Act expands a federal financial assistance program to help companies develop, license, and construct advanced nuclear reactors, as well as build the related infrastructure and supply chain needed to support them. The legislation broadens eligible uses of the program beyond just research and development to include commercial planning, licensing, and construction costs, plus expenses related to transmission systems, microgrids, and upgrading fossil fuel power plant sites for nuclear use. The bill also enhances workforce development by extending funding through 2027 and expanding training programs to include community colleges, trade schools, and apprenticeships alongside universities, with a focus on areas like nuclear construction, operation, and workforce retraining. The measure directs the Department of Energy to prioritize projects that demonstrate cost competitiveness and develop supporting services like market analysis and site preparation for advanced nuclear reactors. Overall, the bill aims to accelerate deployment of next-generation nuclear technology by removing financial and workforce barriers to commercialization.