[en] The Molten Salt Breeder Reactor (MSBR) is a class of generation IV nuclear reactor, where the proposed fuel, in the form of molten salt, will be circulated through the heat exchangers. NaF is the component of secondary coolant salt (FLiNaK) and of proposed alternative fuel salt for MSBR. Mn is structural material (Ti modified Hastelloy) component which can interact with NaF at high temperatures to form Na₂MnF₅(s). Coolant salt FLiNaK is in direct contact with structural material at temperature varying from 723K to 873K. Hence, there is a possibility of formation of Na₂MnF₅(s) during reactor operation. Also, Na₂MnF₅(s) shows superior electrochemical properties which leads to its application as positive electrode material for Na ion battery. In the present work, we report enthalpy of formation of ternary fluoride, Na₂MnF₅(s)

[en] Knowledge on thermodynamic properties of compounds of LiF-UF₄ system is of immense importance for understanding the behaviour of MSBR fuel. In view of this, thermodynamic stability LiUF₅ has been investigated. The compound was prepared by solid state reaction and characterized by powder XRD and TGDTA techniques. The molar enthalpy of dissolution of LiUF₅ and its constituent components was measured in molten LiF: UF₄ eutectic mixture at 885K employing a high temperature Calvet calorimeter. Combining the experimentally determined values of the reaction enthalpies with the auxiliary data from the literature, the standard molar enthalpy of formation of the compound at 298 K (Δ_fH°₂₉₈) was calculated. The Δ_fH°₂₉₈ of LiUF₅(s) at 298 K was found to be – (2708.69± 8.3) kJ mol^-1. (author)

[en] In recent years there is revival of interest on MSBR research programme in India for the effective utilization of large thorium reserves. Proposed secondary coolant for IMSBR (Indian Molten Salt Breeder Reactor) is eutectic mixture of LiF, NaF and KF in mole ratio 46.5:11.5:42 respectively. During reactor operating conditions, there is possibility of formation of KMnF₃(s) compound due to interaction between FLiNaK and structural material (Ti modified Hastelloy-N). Hence, in the present work standard molar enthalpy of formation of this compound has been determined. Also, perovskite-structured KMnF₃(s) has been identified as one of the good supporters for lanthanide up-conversion emission. In the present study, KMnF₃(s) was synthesized using co-precipitation method. Powder X-ray diffraction (XRD) technique was used to confirm the phase purity of the solid product obtained. The obtained XRD pattern matches well with the reported pattern (PCPDF/84-0441)

[en] Dissolution of NdF₃ and SrF₂ in MSBR fluoride salt (FS) mixture (78 mol % LiF-20 mol % ThF₄-2 mol % UF₄)has been investigated by DTA and high temperature drop calorimeter. DTA results indicate that NdF₃ is soluble in FS below 1.0 mol. %, whereas SrF₂ is soluble below 5 mol. %. The exact solubility limit these salts in the FS at 700°C has been determined employing a high temperature solution calorimeter. (author)

[en] Full text: Nanocrystalline Yttria powders were prepared by the citrate-gel combustion synthesis (CS) by microwave mode of heating. The influence of the fuel (citric acid) to oxidant (yttrium nitrate) ratio on the characteristics of the final product was investigated. It was observed that F/O ratio has a strong bearing on the structural aspects of powder synthesized by CS. Thermogravimetric study was carried out to determine the decomposition temperature of precursor obtained by the gel combustion synthesis of Yttria. The combustion residue was calcined in air at 1073 K. The yttria powders thus obtained were characterized for their specific surface area, X-ray crystallite size, bulk density, particle size distribution and residual carbon content. The variation of Specific Surface Area (S.S.A.), X-ray crystallite size (XCS) and Green density (G.D.) vs F/O ratio is shown. These powders were compacted and sintered at 1473 and 1673 K. The sinterability of these powders was compared by measuring the density of the sintered pellets. It was observed that a fuel to oxidant ratio of 1:0.75 yielded a powder that could be cold compacted without the addition of binders or lubricants and sintered to a maximum density of 99 % theoretical density (T.D.) at a temperature as low as 1473 K. The SEM micrograph of the powder shows microporosity while that of the pellet shows extensive grain growth

[en] To evaluate the role of smoking as a risk factor for the development of pulmonary tuberculosis. A total of 111 sputum smear-positive patients of pulmonary tuberculosis and 333 controls matched for age and sex were interviewed according to a predesigned questionnaire. The adjusted odd ratio of the association between tobacco smoking and pulmonary tuberculosis was 3.8 (95% confidence interval, 2.0 to 7.0; P value, < .0001). A positive relationship between pack years, body mass index and socioeconomic class was also observed. There is a positive association between tobacco smoking and pulmonary tuberculosis. (author)

[en] In this report we communicate the behavior of NdF₃ and SrF₂ doped in MSBR fluoride salt (78 mol% LiF-20 mol% ThF₄-2 mol% UF₄) up to 750 °C as observed from DTA and XRD. The eutectic composition of the fuel salt exists as Li₃ThF₇ and LiF. Formation of phases on addition of SrF₂ and NdF₃ in the eutectic mixture resulted in marginal shift in the melting point and the system shifted to ternary phase field of Li₃ThF₇-LiF-NdF₃/SrF₂. Additionally, incorporation of SrF₂ in fuel salt resulted in precipitation of compounds like SrThF₆ and a phase in the quaternary Li-Sr-Th-F system. (author)

[en] In recent years there is a revival of interest in the Molten Salt Breeder Reactors (MSBR). MSBRs are inherently safe reactors with several other advantages like online reprocessing of spent fuel, potential to achieve self sustainable ²³³U/Th cycle, reliability, proliferation resistance etc. LiF, ThF₄ and UF₄ salt mixture is one among the probable candidates for MSBR application. Information on the physico-chemical properties like viscosity of molten coolant, blanket and fuel salt is an important parameter required for successful design and operation of these reactors. In the present work, viscosity of three fluoride based salt eutectic systems such as: fuel salt (LiF = 78 mole %, ThF₄ = 20 mole%, UF₄ = 2 mole%), blanket salt (LiF =77.5 mole %, ThF₄ = 22.5 mole %) and coolant salt (LiF = 46.5 mole %, NaF = 11.5 mole %, KF = 42 mole %) is reported