Martin Šefl received an award from the Czech Society for Radiation Protection for his paper “Inhalation of soluble plutonium: 53-year follow-up of Manhattan Project worker,” which was published in the peer-reviewed journal Health Physics. The award was for the best work written by a young scientist in the field of radiation protection. His paper models the biokinetics of plutonium in a Registrant who was one of 26 Manhattan Project workers known informally as the “UPPU Club.” This group of plutonium-exposed workers were followed up by Los Alamos National Laboratory on a regular basis. Mr. Šefl’s work determined that the worker inhaled a combination of soluble and insoluble plutonium, and calculated doses associated with that intake.