* radionuclides (such as the radiofodines) reach an equilibrium condition where the rate of formation and rate of decay are approximately equal in a few days or a few weeks after start-up, while others (such as strontium 90) do not reach equilibrium during the normal fuel cycle. In fuel reprocessing plants the longer half-lived material is present and must be contained; however, the short-lived materials are soon be Low detectable levels. In regards to underground nuclear weapons tests, radionuclides from fissioning are formed simultaneously and then decay with their characteristic radioactive half-lives. The value for "curies buried at sea". by the United States was zero . in 1968. The three categories "contained in tanks", "solidified and stored", and “trapped underground in cavity glass" contain almost all the curies in the totals. Question 1C Pd PS PS PS PS OS PS OS Can the 1968 estimated total be broken down a third way: '. of source? curies directly from reactor operation? euries from fuel reprocessing? euries from explosive fabrication? into categories : curies from Plowshare excavation tests? curfes. from Plowshare buried tests? curfes from all military tests combined? curtes from medical and industrial operations? curies of nuturnl radionuclides liberated in fuel mining and in the burning of coal? "Isn't such data essential in order to match a particular benefit with its appropriate risk? *