This bill, known as the "Nuclear Forensics Authority Realignment Act," aims to realign Federal nuclear forensics and attribution activities by transferring them from the Department of Homeland Security (DHS) to the National Nuclear Security Administration (NNSA). A central provision of the bill is the establishment of a National Nuclear Forensics Center within the NNSA. This new Center will be responsible for coordinating all Federal nuclear forensics and attribution activities, including stewardship, planning, assessment, and research and development. The Center's mission is to ensure an enduring national technical nuclear forensics capability, thereby strengthening the United States' collective response to nuclear terrorism or other nuclear attacks. Furthermore, the NNSA Administrator must develop a plan to integrate nuclear forensics expertise into the agency's university programs within one year. To facilitate this realignment, the bill repeals the Nuclear Forensics and Attribution Act and makes necessary conforming amendments to the Homeland Security Act of 2002. These amendments specifically remove the nuclear forensics functions previously housed within the Countering Weapons of Mass Destruction Office of DHS, ensuring a clear transfer of authority and responsibilities.