ARPA-E Reauthorization and Reform Act of 2019 This bill revises and reauthorizes requirements governing the Advanced Research Projects Agency-Energy (ARPA-E) in the Department of Energy (DOE). This bill requires ARPA-E to overcome the long-term and high-risk technological barriers in the development of transformative science and technology solutions to address energy, environmental, economic, and national security challenges. (Currently, ARPA-E must overcome barriers in the development of energy technologies.) The bill expands the goals of ARPA-E to include the development of energy technologies that provide transformative solutions to improve management of radioactive waste, improve the efficiency and reduce the environmental impact of energy production, and address other challenges within the mission of DOE. The bill expands the responsibility of ARPA-E to accelerate novel early-stage research to include nonenergy research. ARPA-E must ensure that it does not fund an advanced technology project unless the prospective grantee has demonstrated sufficient attempts to secure private financing or that such project is not independently commercially viable.