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[en] Reaction rates for both big-bang and stellar nucleosynthesis calculations can be obtained from the measurement of (n,p) (n, α) and (n,γ) cross sections for radioactive nuclei. In the past, large backgrounds associated with the sample activity limited these types of measurements to radioisotopes with very long half lives. The advent of the high-intensity neutron source at the Los Alamos Neutron Scattering CEnter (LANSCE) has greatly increased the number of nuclei which can be studied. Results of recent measurements on samples with half lives as short as fifty-three days are given. Plans for future measurements are discussed. 32 refs., 3 figs
[en] Progress made by the Accelerator Mass Spectrometry (AMS) facility at the China Institute of Atomic Energy (CIAE) since 1999 is reported in terms of system upgrades, exploration with other long-lived isotopes, advancements in methodology, and new applications.
[en] The nuclear fuel cycle and its radioactive wastes has played a key role in the nuclear power development and debate for decades. This is true, particularly regarding questions related to disposal of spent fuel and other-lived waste. Most of the long lived waste existing today is fuel used in the reactors. The main part is stored at the reactors sites and normally in water pools or on increasing scale in dry storage containers. Large quantities have also been reprocessed or are stored at reprocessing plants or in long term interim storage facilities. There is in general no urgent need for final disposal of the high level long lived wastes, neither the fuel nor the vitrified wastes. A long interim storage period will facilitate a permanent solution for both categories as radioactivity and heat generation decays. The overall objective of radioactive waste management is to achieve a process within the whole nuclear fuel cycle that well protects man and environment from being harmed. The process should as much as possible limit burdens on future generations by for example reducing the quantities of wastes, minimize environmental impact, encourage efficient utilization of energy resources and keep various options open. Much of this can be met with today's technology and existing knowledge, planning, and regulations which together will guarantee a very safe handling and disposal as long as the waste management is carried out in a correct and well controlled way. The most important goal for safety is, however, -for all kinds of wastes- to keep them well isolated for the first one thousand years and during the relatively short time needed for fission products as cesium and strontium to decay. There exists a well founded international consensus that an isolation system based on geological disposal and use of a multi barrier system could form a very appropriate and technically simple method to achieve robust isolation with large safety margins. (O.M.)
[en] Superphenix operation is used to test qualify industrial ways in plutonium burning and minor actinide transmutation research fields. The 'Knowledge Acquisition Programme' has been set up in common by R and D organisms and the owner/operator. It includes global core modifications in a step by step progression from breeding to burning, demonstration tests on full size subassemblies for advanced plutonium burning solutions (CAPRA programme), specific irradiation of fuel subassemblies dedicated to neptunium and americium transmutation (SPIN programme). Subassembly manufacturing will be carried out from industrial techniques and irradiations will follow reactor cycles. (authors)