For environmental-effects research related to energy technologies and their use, focusing on the impacts of climate and atmospheric changes on the physiology, growth, and biogeochemical cycles of North American forest ecosystems.
For pioneering research and development of new materials for advanced energy technologies, including materials for (a) the storage of nuclear waste, (b) the solid-state generation of electrical power directly from heat, and (c) the lossless transport of electricity.
For contributions to the development of new concepts and advanced systems for power generation and conversion, through innovative designs of nuclear reactors for aircraft propulsion and space auxiliary power and concepts for thermonuclear fusion reactor power plants
For original studies of the genetic effects of radiation in mammals. A world authority on mammalian mutagenesis, he and co-workers provided the experimental basis for estimating the genetic hazards of radiation to man and for the corresponding recommendations of national and international standards bodies