Nuclear fuel waste

Neutron-rich lanthanide isotopes occur in the fission of uranium or plutonium and ate separated during the reprocessing of nuclear fuel wastes (see Nuclearreactors). Lanthanide isotopes can be produced by neutron bombardment, by radioactive decay of neighboring atoms, and by nuclear reactions in accelerators where the rate earths ate bombarded with charged particles. The rare-earth content of solid samples can be determined by neutron... 

Zirconium phosphate [13772-29-7] also absorbs cesium and other radioactive-decay daughter products, and has been proposed as part of permanent disposal systems for nuclear fuel waste processing. 

Wiles, D. R. The Chemistry of Nuclear Fuel Waste Disposal Polytechnic International Press Montreal, Canada, 2001. 

In 1976 he was appointed to Associate Professor for Technical Chemistry at the University Hannover. His research group experimentally investigated the interrelation of adsorption, transfer processes and chemical reaction in bubble columns by means of various model reactions a) the formation of tertiary-butanol from isobutene in the presence of sulphuric acid as a catalyst b) the absorption and interphase mass transfer of CO2 in the presence and absence of the enzyme carboanhydrase c) chlorination of toluene d) Fischer-Tropsch synthesis. Based on these data, the processes were mathematically modelled Fluid dynamic properties in Fischer-Tropsch Slurry Reactors were evaluated and mass transfer limitation of the process was proved. In addition, the solubiHties of oxygen and CO2 in various aqueous solutions and those of chlorine in benzene and toluene were determined. Within the framework of development of a process for reconditioning of nuclear fuel wastes the kinetics of the denitration of efQuents with formic acid was investigated. 

Stokes, J. and Thunvik, R., "Investigations of Groundwater Flow in Rock Around a Repository for Nuclear Fuel Waste", KBS TR 47, 1978... 

The behaviour of technetium in the geosphere is of particular importance in nuclear fuel waste management studies because this man-made element has a long half-life and, under ambient conditions in the laboratory, is not readily sorbed on geologic materials. 

The fissioning of U and Pu in a nuclear reactor produces a large number of radioactive fission products. Most of these decay to stable isotopes within a few minutes to a few years after the fuel has been discharged from the reactor and therefore pose no problem in the management of nuclear fuel wastes. There are, however, a number of longer lived radionuclides that must be considered in assessing the environmental impact of any nuclear fuel waste disposal vault in the geosphere. 

The technetium isotope of interest for nuclear fuel waste disposal is Tc. It is a pure 3-emitter (E = 0.293 MeV) with a half-life of 2.13x10 years. Its high fission yield of 6% accounts for the relatively high concentration 0.02% by weight) (1) in fuel discharged from a CANDU (CANada Deuterium Uranium) reactor (burnup 650 GJ/kg U). 

Solutions. The following solutions were used in one or more of the experiments. With the exception of the distilled water, they reflect the composition of the solutions that may be expected to be present in and around a nuclear fuel waste vault. Their chemical compositions are given in Table II. 

AMOUNT, FORM, AND CONTENT OF NUCLEAR FUEL WASTE CONSTITUENTS... 

Ross J. D. and Gascoyne M. (1995) Methods of Sampling and Analysis of Groundwaters in the Canadian Nuclear Fuel Waste Management Program. Technical Report 588COG-93-36, Atomic Energy of Canada Limited, Pinawa, Manitoba. 

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