Uranium plutonium

Its importance depends on the nuclear property of being readily fissionable with neutrons and its availability in quantity. The world s nuclear-power reactors are now producing about 20,000 kg of plutonium/yr. By 1982 it was estimated that about 300,000 kg had accumulated. The various nuclear applications of plutonium are well known. 238Pu has been used in the Apollo lunar missions to power seismic and other equipment on the lunar surface. As with neptunium and uranium, plutonium metal can be prepared by reduction of the trifluoride with alkaline-earth metals. 

These variations permit the separation of other components, if desired. Additional data on uranium, plutonium, and nitric acid distribution coefficients as a function of TBP concentration, solvent saturation, and salting strength are available (24,25). Algorithms have also been developed for the prediction of fission product distributions in the PUREX process (23). 

Uranium—Plutonium Partitioning". The uranium and plutonium are separated in the partitioning column by reducing the plutonium to a less extractable valence state. The plutonium nitrate transfers back to the aqueous phase and the uranium remains with the organic. 

A variant of the HWR is the Eugen reactor developed by Japan. This reactor is heavy water-moderated but lightwater-cooled. It is fueled by mixed uranium—plutonium oxides. 

Spent fuel can be stored or disposed of intact, in a once-through mode of operation, practiced by the U.S. commercial nuclear power industry. Alternatively, spent fuel can be reprocessed, ie, treated to separate the uranium, plutonium, and fission products, for re-use of the fuels (see Nuclear REACTORS, CHEMICAL reprocessing). In the United States reprocessing is carried out only for fuel from naval reactors. In the nuclear programs of some other countries, especially France and Japan, reprocessing is routine. 

Phosgene can be employed in a variety of metal-recovery operations, eg, in the recovery of platinum, uranium, plutonium, and niobium (69—73). Phosgene has been proposed for the manufacture of aluminum chloride, beryllium chloride, and boron trichloride (74—76). Phosgene has been patented as a stabilizer, either by itself or in combination with thionyl chloride, for Hquid SO2 (77). 

IAEA, The Plutonium—Ouygen and Uranium—Plutonium—Ocygen Systems, Technical Report No. 79, IAEA, Vieima, Austria, 1967. 

Uranium and mixed uranium—plutonium nitrides have a potential use as nuclear fuels for lead cooled fast reactors (136—139). Reactors of this type have been proposed for use ia deep-sea research vehicles (136). However, similar to the oxides, ia order for these materials to be useful as fuels, the nitrides must have an appropriate size and shape, ie, spheres. Microspheres of uranium nitrides have been fabricated by internal gelation and carbothermic reduction (140,141). Another use for uranium nitrides is as a catalyst for the cracking of NH at 550°C, which results ia high yields of H2 (142). 

The Plutonia-Oxygen and Uranium-Plutonium-Oxygen Systems ... 

Green, D. W. Fink, J. K. Leibowitz, L. "Vapor Pressures- and Vapor Compositions in Equilibrium with Hypostoichiometric Uranium-Plutonium Dioxide at High Temperatures," presented at the 8th European Conference on Thermophysical Properties, Baden-Baden, September 27 - October 1, 1982 to be published in High Temperatures-High Pressures. 

Erdal, B.R. Aguilar, R.D. Bayhurst, B.P. Daniels, W.R. Duffy, C.J. Lawrence, F.O. Maestas, S. Oliver, P.Q. Wolfsberg, K. "Sorption-Desorption Studies on Granite. I. Initial Studies of Strontium, Technetium, Cesium, Barium, Cerium, Europium, Uranium, Plutonium, and Americium", in "Proceedings of the Task 4 Waste Isolation Safety Assessment Program Second Contractor Information Meeting", Vol. II, Report PNL-SA-7352, Battelle Pacific Northwest Laboratory, 1978, pp. 7-67. 

Holden NE (1989) Total and spontaneous fission half-lives for uranium, plutonium, americium and curium nuclides. Pure Appl Chem 61(8) 1483-1504... 

Commercial-scale application of solvents coming under the category of neutral reagents is largely found as applied to the nuclear industry materials, as in example, for the separation and refining of uranium, plutonium, thorium, zirconium, and niobium. A process flowsheet for extracting niobium and tantalum from various resources is shown in Figure 5.23. It will... 

Durbin PJ. 1973. Metabolism and biological effects of the transplutonium elements. In Hodge HC, Stannard JN, Hursh JB, eds. Uranium, plutonium, transplutonic elements. New York Springer-Verlag, 739-896. 

Durbin, P. W. (1973). Metabolism and biological effects of the transplutonium elements, page 739 in Uranium, Plutonium, and the Transplutonic Elements, Handbook of Experimental Pharmacology, Vol. 36 (Springer-Verlag, Berlin). 

Iron titanates, 25 46 47 Iron titanium brown spinel, formula and DCMA number, 7 348t Iron trimer, 16 62 Ironworks, early American, 14 492 Iron/Zinc/Magnesium Oxide Tan pigment for plastics, 7 369t Irradiated uranium, plutonium separation and purification from, 19 674-675 Irradiation... 

Uranium phosphates, 25 432-434 Uranium-phosphine coordination complexes, 25 436 Uranium pickling, 9 788 Uranium-plutonium fuels, 19 668... 

Research and development activities for thorium fuel cycles have been conducted in Germany, the USA, India, Japan, Russia and the UK during the last 30 years at a much smaller scale than uranium and uranium-plutonium cycles. Nowadays, India, in particular, has made the utilisation of thorium a major goal in its nuclear power programme, as it has ambitious nuclear expansion plans and significant indigenous thorium resources. 

As indicated earlier Kraus (9) has recognised three types of hydrolysis products of tetravalent thorium, uranium, plutonium and americium. These products are ... 

Several reviews are contained in the following Uranium, Plutonium, Transplutonic Elements. Hodge, H.C., Stannard, J.B., Hursh, J.B. (Eds.). Berlin, Heidelberg, New York Springer 1973... 

Plutonium exists in trace amounts in nature. Most of it isotopes are radioactive and manmade or produced by the natural decay of uranium. Plutonium-239 is produced in nuclear reactors by bombarding uranium-238 with deuterons (nuclei of deuterium, or heavy hydrogen). The transmutation process is as follows + deuterons—> 2 nuclei + Np + p— ... 

Heat capacity data for ions in aqueous solution over the temperature range 25-200°C. Such data for ionic species of uranium, plutonium, other actinides and various fission products such as cesium, strontium, iodine, technetium, and others are of foremost interest. 

Synthesis of plutonium in significant quantities requires a sufficiently long reactor fuel irradiation period. Uranium, plutonium, and the fission products obtained after neutron irradiation are removed from the reactor and stored under water for several weeks. During such cooling periods most neptunium-239 initially formed from uranium and present in the mixture transforms to plutonium-239. Also, the highly radioactive fission products, such as xenon-133 and iodine-131 continue to decay during this period. 

Xenon occurs in the atmosphere at trace concentrations. It also occurs in gases from certain mineral springs. Xenon also is a fission product of uranium, plutonium, and thorium isotopes induced by neutron bombardment. The radioactive fission product, xenon-135, has a very high thermal neutron cross-section. The element has been detected in Mars atmosphere. 

GENERALIZED RECP ACCOUNTING FOR BREIT EFFECTS URANIUM, PLUTONIUM AND SUPERHEAVY ELEMENTS 112, 113, 114... 

Different nuclear models and contributions of the Breit interaction between valence, inner and outer core shells of uranium, plutonium and superheavy elements El 12, E113, and El 14 are considered in the framework of allelectron four-component and (G)RECP methods. It is concluded on the basis of the performed calculations and theoretical analysis that the Breit contributions with inner core shells must be taken into account in calculations of actinide and SHE compounds with chemical accuracy whereas those between valence and outer core shells can be omitted. 

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