Low-Dose Radiation Research Act of 201 9 This bill requires the Department of Energy to conduct a research program on low-dose and low-dose-rate radiation to enhance the scientific understanding of the effects of exposure and to improve risk-assessment and risk-management methods. Low-dose radiation means a dose of less than 100 millisieverts. Low-dose-rate radition means a radiation dose rate of less than 5 millisieverts per hour. (For comparison, the Nuclear Regulatory Commission limits an adult's annual occupational radiation dose to 50 millisieverts and dose rate to approximately .025 millisieverts per hour.)