Stable enriched isotopes and the use of isotope targets for radioisotope productions

Suvorov, I.A.; Tcheltsov, A.N.

doi:10.1016/0168-9002(89)90154-x

Cited by 11 publications

(3 citation statements)

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“…At present, gaseous centrifuges are the most efficient technology for the enrichment of uranium regenerate and correcting its isotopic composition [3,4]. Here it should be noted that when regenerate is enriched in 235 U, the product is also enriched in 232 U.…”

Section: Introduction Of a Carrier Gasmentioning

confidence: 94%

Correcting the isotopic composition of regenerated uranium with respect to 232U by a centrifuge method with introduction of a carrier gas

et al. 2008

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Theoretical and experimental studies dealing with correcting the isotopic composition of regenerated uranium with respect to 232 U by a centrifuge method with introduction of a carrier gas are reported. In order to increase the efficiency of separating 232 U from the spent uranium and reduce the loss of 235 U, the use of a carrier gas is proposed -the gaseous compound 12 C 8 H 3 F 13 , which is inert to uranium hexafluoride, and whose molecular weight, M c = 346 amu, matches that of 232 UF 6 . Freon, C 8 H 3 F 13 , is shown not to decompose during operation in the rotor of a centrifuge or to interact with the centrifuge material. The measured absorption parameters of freon on sodium fluoride NaF confirm the feasibility of efficient separation of a mixture of uranium hexafluoride and freon with return of the freon to the separation process. It is shown that introducing a carrier gas into the centrifuge technology can yield some new results: lowering the radioactivity of the commercial product, normalizing the overall radiation situation during production, increasing the recovered 235 U in the commercial product, and reducing the volume of radioactive waste. The recovery of 235 U in the commercial product can be increased to 99% or more. Then the 232 U content in the commercial product is ~2·10 -8 % or a factor of 10 less than the maximum allowable content of 2·10 -7 %.Correcting the isotopic composition of regenerated uranium with respect to 232 U is an especially important task in connection with the anticipated expansion in the amount of reprocessing of spent nuclear fuel for the closed fuel cycle for large scale nuclear power generation [1,2].The purpose of this paper is to study the problems at a separations plant owing to the isotopic composition of uranium in spent nuclear fuel from nuclear power plants using light water reactors.The use of regenerated uranium can lead to significant savings of natural uranium and economy in separation processing, since the amount of 235 U in spent fuel from VVER or PWR reactors is higher than in natural uranium ( Table 1). The regenerated product contains 232 U (~10 -7 %), whose decay chain includes 208 Tl which is a high energy γ emitter, 234 U (~0.05%), which is an intense α emitter, 235 U (~1%), and 236 U, which is a strong neutron absorber.The presence in the spent fuel of 232 U, with its highly active γ-emitting decay products, makes it more difficult to use regenerated uranium in a closed nuclear fuel cycle. The high γ activity of the daughters of 232 U makes regenerated uranium unsuitable for use in modern nuclear fuel preparation technology.

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Section: Introduction Of a Carrier Gasmentioning

confidence: 94%

Correcting the isotopic composition of regenerated uranium with respect to 232U by a centrifuge method with introduction of a carrier gas

et al. 2008

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“…As seen from Eqs. (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19), all parameters of the multicomponent mixture flow are complexly interconnected with each other and depend on the space distribution of component concentrations. The definition of flow parameters and distribution of concentrations is a sophisticated problem even with the use of modern numerical methods.…”

Section: Borisevich and Levinmentioning

confidence: 99%

Separation of Multicomponent Isotope Mixtures by Gas Centrifuge

Borisevich

Levin

2001

Separation Science and Technology

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“…The proposed unit was " 19 F1," i.e., 1/19 of the atomic mass of elemental fluorine [4]. The proposed unit was " 19 F1," i.e., 1/19 of the atomic mass of elemental fluorine [4].…”

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confidence: 97%

Monoisotopic elemental fluorine as a base for chemical measurements

2009

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High precision chemical measurements (six significant figures) under modern conditions of high demand for consumer and scientific products have acquired undeniable importance. Hence follows the need to formulate the problem of the uniformity of chemical measurements and ways to solve it, i.e., establishing the initial concepts of chemical metrology and correct construction of a system of chemical measures.Motion is one of the most obvious properties of matter. Its measure is expressed in terms of rest. The classical example is the metrology of the mechanical-physical form of the motion of matter with its fundamental units (m, kg, sec) and the Gaussian "dimensional relations" [1,2].Since the most complex forms of the motion of matter do not reduce to a mechanical form, to take account of their specific nature new special units had to be introduced and the corresponding derivative measures tied to them. The choice of these units of measurement ("1") has turned out to be a quite difficult problem. This is why the degree, the ampere, and the candela were finally introduced into a coherent system of measurements only in 1954. Unfortunately, nothing was said in this system of measurements about a basic unit of measurement for the chemical form of the motion of matter.The chemical form of the motion of matter is characterized by a change in composition during a chemical reaction, and chemical analysis of the products of equilibrium can be taken as its measure [1]. Although the history of chemical metrology can be discussed only in conditional terms, one should not think that chemical measurements and their status and measures for improvement have been deprived of detailed and long theoretical and experimental investigations. In this connection, it should be recalled that even Newton stated the main chemical idea that "balances must become the basic tool of chemists." But it was clearly understood only later that in chemical measurements the ordinary units of mass are best replaced by mass on the atomic scale of the chemical elements.The basic units of measurements of the chemical form of the motion of matter -hydrogen " 1 H1" and oxygen " 16 O1" units -were introduced previously. However, in spite of the great benefit for chemical science, these units did not completely meet the specific requirements of chemical metrology [3]. This is why once again chemical metrology is faced with the problem of choosing a new basic unit of measurement.In 1961, the chemical branch of the Academy of Sciences of the USSR decided to adopt as the main unit of measurement of the chemical form of the motion of matter the carbon unit " 12 C1," mainly recommended by physicists and international nongovernmental organizations -International Union of Pure and Applied Chemistry (IUPAC) and International Union of Pure Applied Physics (IUPAP).According to the specific nature of chemical measurements, the prototype of the main unit of measurement is, ordinarily, a consumptive quantity. Fifty years later chemists still do not possess an accumulated pr...

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Stable enriched isotopes and the use of isotope targets for radioisotope productions

Cited by 11 publications

References 0 publications

Correcting the isotopic composition of regenerated uranium with respect to 232U by a centrifuge method with introduction of a carrier gas

Correcting the isotopic composition of regenerated uranium with respect to 232U by a centrifuge method with introduction of a carrier gas

Separation of Multicomponent Isotope Mixtures by Gas Centrifuge

Monoisotopic elemental fluorine as a base for chemical measurements

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