Radionuclide release under specific accident conditions for the Zion plant - BMI-2104 update

The possibility of radioactive material being released to the environment from LWRs has long been the impetus for considerable concern and research. Most reactors in the United States were designed, and their sites were chosen, on the basis of research report TID-14844. Published in 1962, TID-14844 makes certain assumptions about the release of fission products to the reactor containment area during a hypothetical severe accident. Although these assumptions are representative of the state of knowledge at the time, the behavior of fission products has become better understood in the intervening years. Accordingly, the Nuclear Regulatory Commission conducted the Reactor Safety Study to reassess the accident risks in U.S. commercial nuclear power plants. The report of that study, known as WASH-1400, was published in 1975 and provided a more comprehensive and physically accurate description of fission product behavior. The amount of fission product release to the environment (the source term) estimated in WASH-1400 has since been used extensively in planning and evaluating reactor operations