Nuclear Forensics Authority Realignment Act This bill reorganizes nuclear forensics and attribution activities of the federal government. Specifically, the bill transfers nuclear forensics activities currently performed by the Department of Homeland Security to the National Nuclear Security Administration (NNSA) within the Department of Energy (DOE). Nuclear forensics is the examination of nuclear and other radioactive materials to determine the origin and history of the material for purposes of law enforcement investigations or assessment of nuclear security vulnerabilities. The bill also establishes the National Nuclear Forensics Center within the NNSA. The center must coordinate stewardship, planning, assessment, and other functions for all federal nuclear forensics and attribution activities. Additionally, the NNSA must develop and implement a plan to modify its university-based research collaboration program to include the development of expertise in nuclear forensics in supporting scientific and engineering advancement in DOE defense and national security program areas.