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Summary  

The Advanced Spent Conditioning Process (ACP) developed by the KAERI is based on pyrometallurgy and the electrolytic reduction plays a central role in transforming spent oxide fuels into metals. The constituents of the spent fuels are distributed between a salt and a reduced metal phase during electrolysis. Lithium metal is produced in a molten LiCl-Li2O cell and then it reacts with the metal oxides of the spent fuel producing Li2O and reduced metals. By focusing on the activity of Li2O and the electric potential, the electrolytic reduction process of the ACP is discussed. Thermodynamic considerations are defined and operation conditions are proposed including Li2O activity and cell potential.

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Summary  

The electrolytic reduction of U3O8 powder was carried out using LiCl-Li2O molten salt in a 20-kg U3O8 batch cell to verify the feasibility of the process. As the current passes the cell, the decomposition of Li2O and the reduction of U3O8 occur simultaneously in a cathode assembly and oxygen gas evolvs at the anode. The results from a 20-kg U3O8 scale cell were compared with data obtained from a bench scale cell. The results suggest a successful demonstration of this process, exhibiting a reduction conversion of U3O8 of more than 99% in a batch.

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Summary  

The electrochemical reduction of uranium oxide in the treatment of spent nuclear fuel requires a characterization of the LiCl-Li2O salt used as a reaction medium. Physical properties, melting and vaporization are important for the application of the salt and thus they have been investigated by differential scanning calorimetry (DSC) and thermogravimetry (TG), respectively. Experimental data suggest LiCl and Li2O compound formations, leading to a melting point depression of the LiCl and a co-vaporization of the LiCl-Li2O salt.

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Abstract  

This paper describes ongoing research into the multi-physics model development of an electrorefining process for the treatment of spent nuclear fuel. A forced convection of molten eutectic (LiCl–KCl) electrolyte in an electrorefining cell is considered to establish an appropriate electro-fluid model within the 3-dimensional framework of a conventional computational fluid dynamic model. This computational platform includes the electrochemical reaction rate of charge transfer kinetics which is described by a Butler–Volmer equation, while mass transport is considered using an ionic transport equation. The coupling of the local overpotential distribution and uranium concentration gradient makes it possible to predict the local current density distribution at the electrode surfaces.

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Abstract  

A study on the separation of lithium isotope was carried out with N4O azacrown ion exchange resin. The lighter6Li isotope concentrated in the solution phase, while the heavier7Li isotope is enriched in the resin phase. Upon column chromatography (0.3 cm I.D.×15.5cm height) using 0.5M NH4Cl as an eluent, single separation factor, α=1.00127 was obtained.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: K. Kim, J. Bae, B. Park, D. Ahn, S. Paek, S. Kwon, J. Shim, S. Kim, H. Lee, E. Kim, and I. Hwang

Abstract  

A pyrochemical processing has become one of the potential technologies for a future nuclear fuel cycle. An integrated multi-physics simulation and electrotransport model of a molten-salt electrolytic process are proposed and discussed with respect to the recovery of pure uranium when using thermochemical data. This study has been performed to provide information for diffusion boundary layers between the molten salt (KCl-LiCl) and electrode. The diffusion-controlled electrochemical model demonstrate a prediction of the electrotransport behaviors of LWR spent fuel as a function of the time up to the corresponding electrotransport satisfying a given applied current based on a galvanostatic electrolysis.

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Thermodynamic transition properties of highly ordered smectic phases

Series of main-chain liquid crystalline polyethers

Journal of Thermal Analysis and Calorimetry
Authors: Y Yoon, R. -M. Ho, F. Li, B. Moon, D. Kim, J. -Y. Park, F. W. Harris, S. Z. D. Cheng, V. Percec, and P. Chu

A series of polyethers have been synthesized from 1-(4-hydroxy-4′-biphenyl)-2-(4-hydroxyphenyl)propane and α, Ω-dibromoalkanes having different numbers of methylene units [TPPs]. Both odd- and even-numbered TPPs [TPP(n=odd)s and TPP(n=even)s) exhibit multiple transitions during cooling and heating and they show little supercooling dependence, indicating close-to-equilibrium nature of these transitions. Combining the structural characterization obtainedvia wide angle X-ray diffraction powder and fiber patterns at different temperatures and the morphological observations from microscopy techniques, not only the nematic liquid crystalline phase but also highly ordered smecticF, smectic crystalG andH phases have been identified. The phase diagrams for both TPP(n=odd)s and TPP(n=even)s have been constructed [1–3]. Thermodynamic properties (enthalpy and entropy changes) during these transitions are studied based on differential scanning calorimetry experiments. The contributions of the mesogenic groups and methylene units to each ordering process can be separated and they indicate the characteristics of these processes thereby providing estimations of the transition types.

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Acta Botanica Hungarica
Authors: S. Y. Kondratyuk, L. Lőkös, J. P. Halda, M. Haji Moniri, E. Farkas, J. S. Park, B. G. Lee, S.-O. Oh, and J.-S. Hur

Data on about 27 new for South Korea species of lichen-forming and lichenicolous fungi, including one new for science genus Verseghya and 11 new for science species, i.e.: Agominia loekoesii, Lecanora pseudosambuci, Nectriopsis verseghyklarae, Polysporina golubkovae, Protoparmeliopsis zerovii, Psoroglaena chirisanensis, Pyrenopsis chejudoensis, Ropalospora chirisanensis, Thelopsis chirisanensis, Trapelia coreana, and Verseghya klarae, as well as 27 taxa newly recorded for the country (Biatora aff. subduplex, Buellia cf. uberior, Caloplaca kedrovopadensis, Catillaria chalybaea, Coenogonium isidiatum, Dibaeis yurii, Halecania australis, H. lobulata, Intralichen christiansenii, Ivanpisutia oxneri, Lecania cf. olivacella, Lecanora lojkahugoi, L. sulphurea, Lecidella mandshurica, Lichenoconium erodens, Micarea lithinella, M. aff. stipitata, Muellerella pygmaea var. pygmaea, Oxneria alfredii, Pertusaria aff. flavocorallina, Phaeosporobolus alpinum, Polycoccum innatum, Porina fluminea, Rinodina xanthophaea, Ropalospora chloantha, Stigmidium cladoniicola, and S. epiramalina) are provided.

Additional localities for the recently reported or described 39 species from South Korea, and for 1 species (Oxnerella safavidiorum) from Iran and China (for the first time for China) are provided.

The following taxa newly recorded for South Korea, i.e. Ivanpisutia oxneri, Lecanora lojkahugoi, Lecidella mandshurica, Rinodina xanthophaea, Ropalospora chloantha, as well as the newly described Buellia chujadoensis and Verseghya klarae found to be rather common in this country.

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Acta Botanica Hungarica
Authors: S. Y. Kondratyuk, L. Lőkös, J. P. Halda, D. K. Upreti, G. K. Mishra, M. Haji Moniri, E. Farkas, J. S. Park, B. G. Lee, D. Liu, J.-J. Woo, R. G. U. Jayalal, S.-O. Oh, and J.-S. Hur

Data on 54 new for China, India, Korea and Russia species of lichen-forming and lichenicolous fungi, including 22 new for science taxa of lichen-forming and lichenicolous fungi, i.e.: Acarospora ulleungdoensis, Amandinea trassii, Aspicilia geumodoensis, Biatora ivanpisutii, Caloplaca patwolseleyae, Catillaria ulleungdoensis, Coenogonium agonimieoides, Gyalidea austrocoreana, G. ropalosporoides, Opegrapha briancoppinsii, O. ulleungdoensis, Phyllopsora loekoesii, Psoroglaena coreana, Psorotichia gyelnikii, Rinodina oxneriana, Scoliciosporum jasonhurii, Staurothele oxneri, Stigmidium coarctatae, Thelocarpon ulleungdoense, Thelopsis loekoesii, Toninia poeltiana, Unguiculariopsis helmutii, and and 7 new species to China (Caloplaca ussuriensis, Megaspora rimisorediata, Rinodina xanthophaea, Rusavskia dasanensis, Xanthoria splendens, Zeroviella coreana, Z. esfahanensis), and 1 new species to India (Zeroviella esfahanensis), and 24 new species to Korea (Agonimia blumii, Arthonia rinodinicola, Buelliella minimula, Dactylospora australis, Endococcus propinguus, Halecania santessonii, Laeviomyces aff. fallaciosus, Lecanora albescens, L. layana, Lecidella scabra, Micarea farinosa, Minutoexcipula aff. mariana, Opegrapha anomaea, O. aff. xerica, Phoma aff. lecanorina, Polycoccum rubellianae, Porina nucula, Pyrenidium actinellum, Rhexophiale rhexoblephara, Rimularia badioatra, Rinodina confragosa, R. milvina, R. occulta, Tremella phaeophysciae), as well as 1 new species to Russia (Verseghya klarae) are provided. Furthermore new for science species of lichenicolous fungus Polycoccum clauderouxii from China is described. Four new combinations, i.e.: Biatora pseudosambuci (Basionym: Lecanora pseudosambuci S. Y. Kondr., L. Lőkös et J.-S. Hur), Buellia pseudosubnexa (Basionym: Hafellia pseudosubnexa S. Y. Kondr., L. Lőkös et J.-S. Hur), Buellia extremoorientalis (Basionym: Hafellia extremorientalis S. Y. Kondr., L. Lőkös et J.-S. Hur), and Sagedia nunatakkorum (Basionym: Lecanora nunatakkorum Poelt) are proposed. Data on conidiomata and conidia for lichenicolous fungus Opegrapha anomea Nyl are for the first time provided.

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Acta Botanica Hungarica
Authors: S. Y. Kondratyuk, L. Lőkös, J. P. Halda, C. Roux, D. K. Upreti, F. Schumm, G. K. Mishra, S. Nayaka, E. Farkas, J. S. Park, B. G. Lee, D. Liu, J.-J. Woo, and J.-S. Hur

Eighteen new to science species, i.e.: 13 taxa from South Korea (Astroplaca loekoesiana S. Y. Kondr., E. Farkas, J.-J. Woo et J.-S. Hur, Buellia ulleungdoensis S. Y. Kondr., L. Lőkös et J.-S. Hur, Candelariella hakulinenii S. Y. Kondr., L. Lőkös et J.-S. Hur, Flavoplaca laszloana S. Y. Kondr. et J.-S. Hur, Lichenostigma epiporpidiae S. Y. Kondr., L. Lőkös et J.-S. Hur, Mikhtomia geumohdoensis S. Y. Kondr., Liu D. et J.-S. Hur, Orientophila dodongensis S. Y. Kondr., L. Lőkös et J.-S. Hur, Physcia orientostellaris S. Y. Kondr., L. Lőkös et J.-S. Hur, Placynthiella hurii S. Y. Kondr. et L. Lőkös, Protoparmeliopsis kopachevskae S. Y. Kondr., L. Lőkös et J.-S. Hur, Psoroglaena sunchonensis S. Y. Kondr., L. Lőkös et J.-S. Hur, Rufoplaca kaernefeltiana S. Y. Kondr., L. Lőkös et J.-S. Hur, Vezdaea poeltiana S. Y. Kondr., L. Lőkös, J. Halda et J.-S. Hur), two species from India (Rusavskia indica S. Y. Kondr. et D. K. Upreti, and R. upretii S. Y. Kondr., G. K. Mishra et S. Nayaka), and two species from Atlantic Europe, i.e.: Spain and Portugal (Xanthoria schummii S. Y. Kondr. and X. lapalmaensis F. Schumm et S. Y. Kondr.), as well as a lichenicolous fungus Leptosphaeria Oxneriae Cl. Roux et S. Y. Kondr. from Asia (Russia and India) are described, illustrated and compared with closely related taxa. Forty species of lichen forming and lichenicolous fungi (i.e.: Acarospora cf. rufescens, Agonimia allobata, A. aff. blumii, Anema decipiens, Anisomeridium aff. albisedum, Bacidia laurocerasi, Cercidospora aff. epipolytropa, C. aff. lobothallia, Dictyocatenulata alba, Fuscopannaria dissecta, Lecanora ussuriensis, Lecidella aff. carpatica, Lemmopsis arnoldiana, Leptosphaeria crozalsii, Lichenostigma cf. bolacinae, L. aff. rupicolae, Lichinella stipatula, L. cribellifera, L. iodopulchra, L. aff. myriospora, Melaspilea proximella, Micarea alabastrites, Opegrapha aff. thelotrematis, Orientophila leucerythrella, Pectenia plumbea, Placynthium tantaleum, Porpidia flavicunda, Psorula rufonigra, Pyrenocarpon aff. thelostomum, Pyrenodesmia duplicata, Pyrenopsis aff. haematina, Ramboldia haematites, Rhizoplaca subdiscrepans, Rimularia gibbosa, Rinodina oxydata, Staurothele frustulenta, Stigmidium cf. clauzadei, Strigula australiensis, Thelenella luridella, Vezdaea leprosa) are for the first time recorded for Korea. Additional locality records for South Korea (74 species) and China (3 species) are also given.

Four new combinations, i.e.: Orientophila chejuensis (for Caloplaca chejuensis S. Y. Kondr. et Hur), Orientophila diffluens (for Lecanora diffluens Hue), Orientophila leucerythrella (for Lecanora leucerythrella Nyl.), and Pyrenodesmia duplicata (for Lecanora duplicata Vain.) are also proposed.

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