Inventories of secondary nuclear materials such as plutonium (Pu), minor actinides (MAs) and reprocessed uranium (RepU), generated in spent fuel in the wake of nuclear electricity production were predicted for the world and Japanese cases by IAEA-VISTA code, which can be applied to the evaluation of the nuclear fuel cycle with thermal power reactors.
One of the major concerns has been the mobility of long-lived transuranic actinides such as plutonium (Pu), americium (Am), and curium (Cm).
Added to such fickleness, plutonium is highly reactive with other metals and materials, especially oxygen and hydrogen.
The quantities of these, plus isotopes of elements such as plutonium that are also created in reactors, vary from one reactor to another.
Several, such as plutonium and americium, if ingested, migrate to the bone marrow, where their radiation interferes with the production of red blood cells.
(Reuters NATOO: URANIUM WEAPONS Trying to calm the furor in Europe about radioactivity in depleted uranium weapons, NATO said possible traces of highly radioactive elements such as plutonium and americium were not relevant to soldiers' health because of their minute quantities.
Mixtures of the isotopes einsteinium-253 (20.5-day half-life), einsteinium-254 (276-day half-life), and einsteinium-255 (39.8-day half-life) can be produced by intensive slow-neutron irradiation of elements of lower atomic number, such as plutonium.
In the 50s and 60s Sellafield was run by the UKAEA, which had a dual mission: research and development for the civilian nuclear programme; and to create the fissile materials, such as plutonium and enriched uranium, and to design and build the warheads for the British atomic bomb programme.
Both reactors have been in use for several years and each would contain about 10,000 million curies of radioactivity in fission products and about 3,000 million curies of what are called heavy actinides - which is the uranium fuel and its derivitives such as plutonium.
Mixtures of the isotopes fermium-254 (3.24-hour half-life), fermium-255 (20.1-hour half-life), fermium-256 (2.6-hour half-life), and fermium-257 (100.5-day half-life) have been produced in a high-neutron-flux reactor by the intense slow-neutron irradiation of elements of lower atomic number, such as plutonium.
