Speaker
Prof.
Frank Carre
Description
Eugene P. Wigner made instrumental advances in reactor physics, reactor design and technology, and spent nuclear fuel processing for both purposes of developing atomic weapons during world-war II and nuclear power afterwards. Wigner really came to nuclear energy through the Manhattan Project, where he could really use his talents of theorist, experimentalist and engineer. Not only his varied contributions were instrumental to the success of the Manhattan Project but they laid the foundations for key technologies, processes and reactor designs that enabled the development of Generation-I through IV fission reactors. Natural uranium fuelled graphite moderated reactors (Gen-I) were directly derived from initial weapon-grade materials production reactors. Wigner’s preference for water cooling for the sake of efficient cooling happen to lay visionary foundations to light water compact reactors that were first used to power submarines and then converted into pressurized and boiling water reactors (Gen-II). These types of reactor that essentially use 235U constitute 85% of the nuclear fleet in the world today and advanced versions that are currently commercialized (Gen-III) will remain the dominant type of nuclear power plants over the 21st century. Gen-IV nuclear systems under development today encompass a wide span of reactors and fuel cycles that are anticipated to play a role over the 21st century. Fast neutron reactors that enable using efficiently 238U that represents 99.3% of uranium gave rise to demonstration sodium-cooled reactors in major nuclear countries. A significant effort is being made in the frame of the Generation-IV Internal Forum to share visions of needed improvements in safety and economics for new generations of fast neutron reactors, be they sodium-cooled, lead-cooled or gas-cooled. Wigner’s contribution to fast reactors lies in precursor solvent-extraction methods for recovering plutonium from spent nuclear fuels and closing the fuel cycle. These examples evidence the wide span of theoretical and technological contributions that Wigner brought to all generation of fission reactors so far, in both fields of chemistry and physics, and how his spirit of skilled theorist and engineer will survive in nuclear systems anticipated for the 21st century.
