Chemical aspects of nitride, phosphide and sulphide fuels

Allbutt, M.; Dell, R.M.

doi:10.1016/0022-3115(67)90076-1

Cited by 39 publications

(4 citation statements)

References 20 publications

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“…However, the use of UN was limited in the early years due to technological problems such as high pyrophoricity of the powder in air, poor water/steam tolerance, high difficulty in sintering the powder to a densified compact, and need for use of N 15 instead of the natural N 14 [6][7][8][9]. The issue related to the nitrogen enrichment persists because it is necessary to have a N 15 concentration greater than 90% to sufficiently increase the neutron economy, reduced by the high absorption cross-section of N 14 .…”

Section: Introductionmentioning

confidence: 99%

Transport properties of C and O in UN fuels

et al. 2017

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Uranium nitride fuel is considered for fast reactors (GEN-IV generation and space reactors) and for light water reactors as a high-density fuel option. Despite this large interest, there is a lack of information about its behavior for in-pile and out-of-pile conditions. From the present literature, it is known that C and O impurities have significant influence on the fuel performance. Here, we perform a systematic study of these impurities in the UN matrix using electronic-structure calculations of solute-defect interactions and microscopic jump frequencies. These quantities were calculated in the DFT+U approximation combined with the occupation matrix control scheme, to avoid convergence to metastable states for the 5f levels. The transport coefficients of the system were evaluated with the self-consistent mean-field theory. It is demonstrated that carbon and oxygen impurities have different diffusion properties in the UN matrix, with O atoms having a higher mobility, and C atoms showing a strong flux coupling anisotropy. The kinetic interplay between solutes and vacancies is expected to be the main cause for surface segregation, as incorporation energies show no strong thermodynamic segregation preference for (001)-surfaces compared with the bulk.

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Section: Introductionmentioning

confidence: 99%

Transport properties of C and O in UN fuels

et al. 2017

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“…237 Np has also been highlighted as a “burnable” isotope for future reactor fuels . In addition to these aspects of Np chemistry, soft chalcogen-containing ligands have been used extensively in actinide organometallic and separations chemistry, and actinide chalcogenides have been investigated as potential fuels for future fast reactors . A fundamental understanding of Np chalcogenide solid-state chemistry is clearly relevant and is needed for these potential applications.…”

Section: Introductionmentioning

confidence: 99%

Quaternary Neptunium Compounds: Syntheses and Characterization of KCuNpS₃, RbCuNpS₃, CsCuNpS₃, KAgNpS₃, and CsAgNpS₃

et al. 2009

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The five quaternary neptunium compounds KCuNpS3, RbCuNpS3, CsCuNpS3, KAgNpS3, and CsAgNpS3 (AMNpS3) have been synthesized by the reaction of Np, Cu or Ag, S, and K2S or Rb2S3 or Cs2S3 at 793 K (Rb) or 873 K. These isostructural compounds crystallize as black rectangular plates in the KCuZrS3 structure type in space group Cmcm of the orthorhombic system. The structure comprises MS4 (M = Cu or Ag) tetrahedra and NpS6 octahedra that edge share to form infinity 2[MNpS3-] layers. These layers are separated by the alkali-metal cations. The Np-S bond lengths vary from 2.681(2) to 2.754(1) A. When compared to the corresponding isostructural Th and U compounds these bond distances obey the expected actinide contraction. As the structure contains no S-S bonds, formal oxidation states of +1/+1/+4/-2 may be assigned to A/M/Np/S, respectively. From these results a value of 2.57 for the bond-valence parameter r0 for Np(4+)-S(2-) has been derived and applied to the estimation of the formal oxidation states of Np in the binary NpxSy compounds whose structures are known.

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“…Nevertheless, the extreme stability at high temperatures (mp ) 2350 °C) and its relative inert behavior toward steam at 250 °C makes PuS an attractive candidate for fast reactor nuclear fuel, possessing chemical stability that exceeds that of nitrides and phosphides. 4 Because of the importance of stockpiles of plutonium to the world energy stores, there still remains a need for the study of fundamental solid-state chemistry of more complex plutonium sulfides.…”

Section: Introductionmentioning

confidence: 99%

“…The fundamental chemistry of plutonium has been summarized in several sources. − Aside from the extensive work in metal oxide chemistry and metallurgy, many of the fundamental bonding characteristics, coordination geometries, and solid-state chemical properties of other compositions of this unusual metal have been overlooked due to the hazards associated with its inherent radioactivity. Nevertheless, the extreme stability at high temperatures (mp = 2350 °C) and its relative inert behavior toward steam at 250 °C makes PuS an attractive candidate for fast reactor nuclear fuel, possessing chemical stability that exceeds that of nitrides and phosphides …”

Section: Introductionmentioning

confidence: 99%

Synthesis and Structural Characterization of the First Quaternary Plutonium Thiophosphates: K₃Pu(PS₄)₂ and APuP₂S₇ (A = K, Rb, Cs)

et al. 2002

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The first quaternary plutonium metal thiophosphates have been synthesized by the reactive flux method and characterized by single-crystal X-ray diffraction: K(3)Pu(PS(4))(2) (I), KPuP(2)S(7) (II), RbPuP(2)S(7) (III), and CsPuP(2)S(7) (IV). All four compounds crystallize in the monoclinic space group P2(1)/c with Z = 4. Compound I has cell parameters of a = 9.157(1) A, b = 16.866(2) A, c = 9.538(1), and beta = 90.610(3)degrees. Compound II has cell parameters of a = 9.641(1) A, b = 12.255(1) A, c = 9.015(1) A, and beta = 90.218(1)degrees. Compound III has cell parameters of a = 9.8011(6) A, b = 12.3977(7) A, c = 9.0263(5) A, and beta = 90.564(1)degrees. Compound IV has cell parameters of a = 10.1034(7) A, b = 12.5412(9) A, c = 9.0306(6) A, and beta = 91.007(1)degrees. Compound I is isostructural to a family of rare-earth metal thiophosphates and comprises bicapped trigonal prismatic PuS(8) polyhedra linked in chains through edge-sharing interactions and through thiophosphate tetrahedra. Compounds II-IV crystallize in a known structure type not related to any previously observed actinide thiophosphates and contain the (P(2)S(7))(4-) corner-shared bitetrahedral ligand as a structural building block. A summary of important bond distances and angles for these new plutonium thiophosphate materials is compared to the limited literature on plutonium solid-state compounds. Diffuse reflectance spectra confirm the Pu(III) oxidation state and Raman spectroscopy confirms the tetrahedral PS(4)(3-) building block in all structures.

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Chemical aspects of nitride, phosphide and sulphide fuels

Cited by 39 publications

References 20 publications

Transport properties of C and O in UN fuels

Transport properties of C and O in UN fuels

Quaternary Neptunium Compounds: Syntheses and Characterization of KCuNpS₃, RbCuNpS₃, CsCuNpS₃, KAgNpS₃, and CsAgNpS₃

Synthesis and Structural Characterization of the First Quaternary Plutonium Thiophosphates: K₃Pu(PS₄)₂ and APuP₂S₇ (A = K, Rb, Cs)

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Chemical aspects of nitride, phosphide and sulphide fuels

Cited by 39 publications

References 20 publications

Transport properties of C and O in UN fuels

Transport properties of C and O in UN fuels

Quaternary Neptunium Compounds: Syntheses and Characterization of KCuNpS3, RbCuNpS3, CsCuNpS3, KAgNpS3, and CsAgNpS3

Synthesis and Structural Characterization of the First Quaternary Plutonium Thiophosphates: K3Pu(PS4)2 and APuP2S7 (A = K, Rb, Cs)

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Quaternary Neptunium Compounds: Syntheses and Characterization of KCuNpS₃, RbCuNpS₃, CsCuNpS₃, KAgNpS₃, and CsAgNpS₃

Synthesis and Structural Characterization of the First Quaternary Plutonium Thiophosphates: K₃Pu(PS₄)₂ and APuP₂S₇ (A = K, Rb, Cs)