Alexander Klementiev was born in Moscow in 1942 and grew up in the Soviet Union during the Cold War. As a student, he attended the Moscow Institute of Physics and Technology, where he studied radio physics and earned his Ph.D. He also served as a research fellow for the International Institute for Applied Systems Analysis in Vienna, Austria. In 1992, Klementiev immigrated to the United States. In this interview, Klementiev describes his work analyzing the mortality of those people who lived in areas contaminated by the Chernobyl reactor accident. He also describes his work estimating radioactive releases from the Hanford Site facilities and the lifetime risk of radiation-induced thyroid disease for the Hanford downwinders. Klementiev also discusses differences between the atmosphere of the United States and Russia.