Recent advances in the study of the UO2–PuO2 phase diagram at high temperatures

Böhler, R.; Welland, M.J.; Prieur, Damien; Cakir, Pelin; Vitova, T.; Pruessmann, Tim; Pidchenko, I.; Hennig, Christoph; Guéneau, C.; Konings, R.J.M.; Manara, D.

doi:10.1016/j.jnucmat.2014.02.029

Cited by 86 publications

(93 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As often observed in rapid laser-heating experiments of such materials, and confirmed by numerical simulation [19], the heating stage often occurs too quickly to reveal an observable melting arrest during this phase of the thermal cycle but could be estimated with the help of the RLS. In general, the obtained temperatures with the RLS upon heating are similar to the ones during cooling [3,4].…”

Section: Laser Melting Experimental Setupsupporting

confidence: 70%

“…Thermal material properties of such systems seem to behave ideally at temperatures well below melting [1], which is shown, for example, for the (Pu, Th)O 2 solid solution with new heat capacity studies by Valu et al [2]. Recent studies on the melting of mixed actinide dioxides ((U, Pu)O 2 [3], (U, Th)O 2 [4]) showed on the other hand a non-ideal behaviour for the high temperature melting/solidification phase transition. Both mixed systems revealed a minimum temperature in the pseudo-binary section and question the validity of an ideal solution assumption for these systems at high temperatures.…”

Section: Introductionmentioning

confidence: 89%

See 1 more Smart Citation

High temperature phase transition of mixed (PuO 2 + ThO 2 ) investigated by laser melting

Böhler

Cakir

Beneš

et al. 2015

The Journal of Chemical Thermodynamics

Self Cite

View full text Add to dashboard Cite

a b s t r a c tA laser heating approach combined with fast pyrometry in a thermal arrest method was used to provide new data for the melting/solidification phase transition in mixed (PuO 2 + ThO 2 ) at high temperature. At low concentration of ThO 2 in PuO 2 a minimum in the solidification temperature in the pseudo binary (PuO 2 + ThO 2 ) was observed. The minimum was found around a composition with 5 mol% ThO 2 . Phase transition temperatures of other compositions are closer to an ideal solution behaviour. To detect changes in the material a complete investigation with electron microscopy, Raman spectroscopy and powder X-ray diffraction was done. Raman vibration modes were found, that are characteristic for materials containing PuO 2 , and high temperature segregation effects during solidification were described. The results obtained in the present work are compared to other mixed actinide dioxides and compared to the ideal solution case for this system. The presented results show the importance of the hightemperature oxygen chemistry in this actinide oxide phase.

show abstract

Section: Laser Melting Experimental Setupsupporting

confidence: 70%

Section: Introductionmentioning

confidence: 89%

High temperature phase transition of mixed (PuO 2 + ThO 2 ) investigated by laser melting

Böhler

Cakir

Beneš

et al. 2015

The Journal of Chemical Thermodynamics

Self Cite

View full text Add to dashboard Cite

show abstract

“…Experimentally reported melting temperatures of UO2 vary from 3050 K to 3138 K ( Table 2) [11][12][13][14][15][16][17][18]. The melting point of UO2 given in MATPRO [15] is 3113.15 K, based on the equations for the solids and liquids boundaries of the UO2-PuO2 phase diagram given by Lyon et al [11].…”

Section: Enthalpy and Density Variation Of Th Rich (Thu)o2 And (Thpmentioning

confidence: 99%

“…ThO2 3650-3675 3663 ± 100 Benz et al [6] 3643 ± 30 Rand et al [7] 3573 ± 100 Lambertson et al [8] 3651 ± 17 Ronchi et al [9] 3624 ± 108 Bohler et al [10] UO2 3050-3075 3113 ± 20 Lyon et al [11] 3138 ± 15 Latta et al [12] 3075 ± 30 Ronchi et al [13] 3120 ± 30 Adamson et al [14] 3,113.15 MATPRO [15] 3138 ± 15 Komatsu et al [16] 3120 ± 30 ORNL [17] 3050 ± 55 Böhler et al [18] PuO2 2800-2825 2663 ± 20 Lyon et al [11] 2701 ± 35 Adamson et al [14] 2647 MATPRO [15] 2718 Komatsu et al [16] 2701 ± 35 ORNL [17] 2843 Kato et al [19] Table 4: MD calculated enthalpy increments (in J/mole) of solid and liquid phases of (Th,U)O2 and (Th,Pu)O2 MOX are fitted to equation (7) and (8), respectively and coefficients are enlisted.…”

Section: Calculated Temperature Range (K) Experimental Values (K)mentioning

confidence: 99%

“…For ThO2, these thermodynamic quantities for the solid phase are available only over a limited temperature range [21][22][23][24]26] and no data is available for the liquid phase. Recently, Böhler et al [18] and Bruycker et al [20] determined melting temperatures of PuO2 using a laser heating method and pyrometry. Valu et al [34] determined enthalpy increments of Th1-xPuxO2 (for x = 0, 0.03, 0.08, 0.30, 0.54, 0.85 and 1) using drop calorimetry in the temperature range 476 K to 1790 K. Still, high temperature enthalpy and density values of solid PuO2, (Th,Pu)O2 and(Th,U)O2 MOX as well as their respective liquid phases are not available.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Melting behavior of (Th,U)O2 and (Th,Pu)O2 mixed oxides

Ghosh

Kuganathan

Galvin

et al. 2016

Journal of Nuclear Materials

View full text Add to dashboard Cite

The melting behaviors of pure ThO2, UO2 and PuO2 as well as (Th,U)O2 and (Th,Pu)O2 mixed oxides (MOX) have been studied using molecular dynamics (MD) simulations. The MD calculated melting temperatures (MT) of ThO2, UO2 and PuO2 using two-phase simulations, lie between 3650-3675 K, 3050-3075 K and 2800-2825 K, respectively, which match well with experiments. Variation of enthalpy increments and density with temperature, for solid and liquid phases of ThO2, PuO2 as well as the ThO2 rich part of (Th,U)O2 and (Th,Pu)O2 MOX are also reported. The MD calculated MT of (Th,U)O2 and (Th,Pu)O2 MOX show good agreement with the ideal solidus line in the high thoria section of the phase diagram, and evidence for a minima is identified around 5 atom% of ThO2 in the phase diagram of (Th,Pu)O2 MOX.

show abstract

Plutonium and Plutonium Compounds

Clark

Freibert

Jarvinen

2017

Kirk-Othmer Encyclopedia of Chemical Technology

View full text Add to dashboard Cite

The discovery of plutonium, its economic and military importance, sources, production, and nuclear properties are reviewed. The economic aspects of weapons‐grade and reactor‐grade plutonium are outlined. The preparation and properties of plutonium metal and its alloys are discussed in detail. A presentation of the physical and chemical properties of atomic plutonium and stable plutonium ions is given. The complexation and hydrolysis properties of these ions are recapitulated. Analytical chemistry, separations technology, and metallurgy (including pyrometallurgical processing) are described. There is a brief treatment of storage and disposal of excess weapons plutonium. The chemistry of several classes of plutonium compounds is described: oxides, halides, oxyhalides, hydrides, carbides, silicides, nitrides, sulfides, and oxalates. The article concludes with a treatment of environmental, health, and safety aspects of plutonium.

show abstract

Recent advances in the study of the UO2–PuO2 phase diagram at high temperatures

Cited by 86 publications

References 38 publications

High temperature phase transition of mixed (PuO 2 + ThO 2 ) investigated by laser melting

High temperature phase transition of mixed (PuO 2 + ThO 2 ) investigated by laser melting

Melting behavior of (Th,U)O2 and (Th,Pu)O2 mixed oxides

Plutonium and Plutonium Compounds

Contact Info

Product

Resources

About