Uranium plutonium thorium

The actinide elements are a group of chemically similar elements with atomic numbers 89 through 103 and their names, symbols, atomic numbers, and discoverers are given in Table 1 (1-3) (see Thorium and thorium compounds Uranium and uranium compounds Plutonium and plutonium compounds Nuclear reactors and Radioisotopes). 

Actinide Peroxides. Many peroxo compounds of thorium, protactinium, uranium, neptunium, plutonium, and americium are known (82,89). The crystal stmctures of a number of these have been deterrnined. Perhaps the best known are uranium peroxide dihydrate [1344-60-1/, UO 2H20, and, the uranium peroxide tetrahydrate [15737-4-5] UO 4H2O, which are formed when hydrogen peroxide is added to an acid solution of a uranyl salt. 

The chemical similarity between lanthanide and actinide metals suggests that C2H I2 might also react with actinide metals. Preliminary experiments found no reaction between thorium or uranium metals and a THF solution of Plutonium and neptunium... 

Dacheux N, Aupiais J (1997) Determination of uranium, thorium, plutonium, americium, and curium ultratraces by photon electron rejecting alpha liquid scintillation. Anal Chem 69 2275-2282 Duan YX, Chamberlin EP, Olivares JA (1997) Development of a new high-efficiency thermal ionization source for mass spectrometry. Inti JMass Spectrom IonProcessesl61 27-39 Edwards RL, Chen JH, Wasserburg GJ (1987) systematics and the precise... 

Dacheux N, Aupiais J. 1997. Determination of uranium, thorium, plutonium, americium, and curium ultratraces by photon electron rejection a liquid scintillation. Anal Chem 69 2275-2282. 

Thorium Protactinium Uranium Neptunium Plutonium Ameridum Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrendum... 

Thorium Protactinium Uranium Neptunium Plutonium Americium... 

Safety considerations in handling plutonium, uranium, thorium, alkali metals, titanium, magnesium, and calcium are discussed. 

This article presents a general discussion of actinide metallurgy, including advanced methods such as levitation melting and chemical vapor-phase reactions. A section on purification of actinide metals by a variety of techniques is included. Finally, an element-by-element discussion is given of the most satisfactory metallurgical preparation for each individual element actinium (included for completeness even though not an actinide element), thorium, protactinium, uranium, neptunium, plutonium, americium, curium, berkelium, californium, and einsteinium. 

Garten CT Jr. 1978. A review of parameter values used to assess the transport of plutonium, uranium and thorium in terrestrial food chains. Environ Res 17 437-452. 

Torstenfelt B. 1986. Migration of the actinides, thorium, protactinium, uranium, neptunium, plutonium and americium in clay. Radiochem Acta 39 105-112. 

Researchers at BNL claim that this technology may be used to extract metals such as cadmium, arsenic, lead, zinc, copper, magnesium, manganese, aluminum, barium, nickel, and chromium, as well as radionuclides such as uranium, thorium, plutonium, cobalt, cesium, and strontium. They state that the process offers the following advantages ... 

Inhalation vs. oral Americium-241 Californium-252 Cesium-137 Cobalt-60 Hydrogen-3 Iodine-125 Iodine-129 Iodine-131 Phosphoms-32 Plutonium-239 Polonium-210 Radium-226 Strontium-90 Thorium-232 Uranium-235... 

Low-Level Waste. Low-level wastes are further divided into categories of special nuclear material, source material, and byproduct material, depending on the isotopes contained. Special nuclear material refers to uranium 233, plutonium 239, and uranium containing more than the natural abundance of uranium 235. Source material refers to materials containing 0.05 percent or more of thorium or uranium in any physical or chemical form except that covered under special nuclear material. By-product materials consist of all other radioactive materials including fission and activation products. 

The coordination geometry in anhydrous Th(CF3COCHCOMe)4 is a 1111 ( )4-422) antiprism 74 the structure of the monohydrate has been discussed earlier (p. 1144). Th[CF3COCHCO(2-C4H3S)]4 is isostructural with the cerium(IV), uranium(IV) and plutonium(IV) analogues. The coordination polyhedron is a distorted dodecahedron in which the four ligands span the two perpendicular trapezoids of the dodecahedron.75 In the complexes M(n-C3F7COCHCOBut)4, the thorium(IV), uranium(IV) and neptunium(IV) compounds are isomorphous, but the plutonium compound is not. 

The use of the thorium-uranium fuel cycle in the HTGR provides improved core performance over the plutonium/uranium low-enrichment... 

The uranium and thorium ore concentrates received by fuel fabrication plants still contain a variety of impurities, some of which may be quite effective neutron absorbers. Such impurities must be almost completely removed if they are not seriously to impair reactor performance. The thermal neutron capture cross sections of the more important contaminants, along with some typical maximum concentrations acceptable for fuel fabrication, are given in Table 9. The removal of these unwanted elements may be effected either by precipitation and fractional crystallization methods, or by solvent extraction. The former methods have been historically important but have now been superseded by solvent extraction with TBP. The thorium or uranium salts so produced are then of sufficient purity to be accepted for fuel preparation or uranium enrichment. Solvent extraction by TBP also forms the basis of the Purex process for separating uranium and plutonium, and the Thorex process for separating uranium and thorium, in irradiated fuels. These processes and the principles of solvent extraction are described in more detail in Section 65.2.4, but the chemistry of U022+ and Th4+ extraction by TBP is considered here. 

ACTINIUM THORIUM PROTACTINIUM URANIUM NEPTUNIUM PLUTONIUM AMERICIUM CURIUM BERKELIUM CALIFORNIUM EINSTEINIUM FERMIUM MENDELEVIUM NOBELIUM... 

Although PUCI4 has been well characterized in the gas phase (51) in the temperature range 670-1025 K, all attempts to obtain tTiTs compound in the solid state have failed. Use of a plot of the difference AHf(MCl4,c) - AHf(M , aq) (, 8) as a function of the actinide ionic radii ( ) (as done above for PuFa) in the case of thorium, protactinium, uranium and neptunium yields a first path leading to aH (PuC14,c). A second path involves the extrapolation to the plutonium system of the difference AH5o n( C 4 ) ... 

Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkellum Caiiiornlum Einsteinium Permium Mendelevlum Nobelium Lawrenaum ... 

The vast majority of the studies reported have concerned the metals thorium and uranium, particularly the latter, due to accessibility of raw materials, ease of handling, and the long lifetimes of the relatively weakly a-emitting elements Th and U. In many cases, compounds of neptunium and plutonium with similar formulae to U and Th analogues have been made and found to be isomorphous and thus presumably isostructural. This chapter will therefore commence with, and concentrate largely on, the chemistry of complexes of these elements, followed by sections on the other actinides. 

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