The Medical Radiobiology Advisory Team (MRAT) is the operations arm of the Armed Forces Radiobiology Research Institute (AFRRI), located at Naval Support Activity in Bethesda, MD. AFRRI is internationally recognized as expert in the biological effects of ionizing radiation research, training, and mitigation. During the U.S. Department of Defense's (DoD) response to the Fukushima Daiichi reactor incident, Operation Tomodachi, the MRAT provided guidance and advice to the U.S. Military leaders in Japan. This support helped ensure the safety of U.S. service members, family members, and civilians and supported the humanitarian relief in a coordinated effort with the Government of Japan (GOJ).