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1

Towards safe and optimized separation processes, a challenge for nuclear scientists : editorial

Bourg S., Narbutt J.

Nukleonika

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2015

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Vol. 60, No. 4, part 2

807

2

SACSESS : the EURATOM FP7 project on actinide separation from spent nuclear fuels

Bourg S., Geist A., Narbutt J.

Nukleonika

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2015

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Vol. 60, No. 4, part 2

809--814

EN

Recycling of actinides by their separation from spent nuclear fuel, followed by transmutation in fast neutron reactors of Generation IV, is considered the most promising strategy for nuclear waste management. Closing the fuel cycle and burning long-lived actinides allows optimizing the use of natural resources and minimizing the long-term hazard of high-level nuclear waste. Moreover, improving the safety and sustainability of nuclear power worldwide. This paper presents the activities striving to meet these challenges, carried out under the Euratom FP7 collaborative project SACSESS (Safety of Actinide Separation Processes). Emphasis is put on the safety issues of fuel reprocessing and waste storage. Two types of actinide separation processes, hydrometallurgical and pyrometallurgical, are considered, as well as related aspects of material studies, process modeling and the radiolytic stability of solvent extraction systems. Education and training of young researchers in nuclear chemistry is of particular importance for further development of this field.

3

Determination of formation constants of uranyl(VI) complexes with a hydrophilic SO3-Ph-BTP ligand, using liquid-liquid extraction

Steczek L., Narbutt J., Charbonnel M. -C., Moisy P.

Nukleonika

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2015

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Vol. 60, No. 4, part 2

821--827

EN

Complex formation between uranyl ion, UO2 2+, and a hydrophilic anionic form of SO3-Ph-BTP4– ligand, L4–, in water was studied by liquid-liquid extraction experiments performed over a range of the ligand and HNO3 concentrations in the aqueous phase, at a constant concentration of nitrate anions at 25°C . The competition for UO2 2+ ions between the lipophilic TODGA extractant and the hydrophilic L4– ligand leads to the decrease in the uranyl distribution ratios, D, with an increasing L4– concentration. The model of the solvent extraction process used accounts – apart from uranyl complexation by TODGA and SO3-Ph-BTP4– – also for uranyl complexation by nitrates and for the decrease in the concentration of the free L4– ligand in the aqueous phase, due to its protonation, bonding in the uranyl complex and the distribution between the two liquid phases. The unusually strong dependence of the D values on the acidity, found in the experiment, could hardly be explained as due to L4– protonation merely. Three hypotheses were experimentally tested, striving to interpret the data in terms of additional extraction to the organic phase of ion associates of protonated TODGA cation with either partly protonated anionic L4– ligands or anionic UO2 2+ complexes with NO3 – or L4–. None of them has been confi rmed. The analysis of the results, based on the formal correction of free ligand concentrations, points to the formation of 1 : 1 and 1 : 2 uranyl – SO3-Ph-BTP complexes in the aqueous phase. The conditional formation constant of the 1:1 complex has been determined, logβL,1 = 2.95 ± 0.15.

4

Trends in radiochemistry at the beginning of the 21st century

Narbutt J.

Nukleonika

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2005

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Vol. 50,suppl.3

77-81

EN

A review on selected - the most important and most prospective - directions of the present-day radiochemistry has been presented, with a special emphasis on the research carried out at the Department of Radiochemistry, Institute of Nuclear Chemistry and Technology.

5

Adsorption of strontium, europium and americium(III) ions on a novel adsorbent Apatite II

Krejzler J., Narbutt J.

Nukleonika

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2003

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Vol. 48, nr 4

171-175

EN

A novel material, Apatite II, obtained from a natural source, has been determined to be a good adsorbent for radionuclides of strontium, europium and trivalent actinides, but not caesium, from neutral aqueous solutions containing common chelating agents and inorganic salts at moderate concentrations. This inexpensive, easily available material seems to be a promising backfill for engineered barriers in nuclear waste repositories. However, encapsulation of the sorbent grains loaded with radiostrontium in the Portland cement matrix results in undesirably high leaching rate for this particular radionuclide.

6

Sorption of long-lived radionuclides from model liquid radioactive wastes on α-crystalline polyantimonic acid

Satyanarayana J., Bilewicz A., Narbutt J.

Nukleonika

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1998

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Vol. 43, nr 4

531-538

EN

A method was investigated for removal and immobilisation of hazardous long-lived radionuclides from liquid radioactive wastes containing macroamounts of other metal ions and complexing agents. Selective inorganic ion exchangers: α-crystalline polyantimonic acid (CAA) and metal antimonates were synthesized and studied as adsorbents for di- and trivalent ions: Sr(sup 2+) and Eu(sup 3+) (a model for actinides), and also monovalent Cs(sup +). High decontamination factors for the two former ions have been attained with CAA. The effect of the concentration of the waste components on the radionuclide sorption was studied. Calcium ions strongly reduce sorption of Sr(sup 2+), and EDTA in neutral solution - that of Eu(sup 3+), while sodium ions, citrates and oxalates have a little effect. Radiocaesium must be removed using another selective ion exchanger.

PL

Badano możliwości usuwania i związania w fazie stałej toksycznych radionuklidów długożyciowych z ciekłych odpadów promieniotwórczych zawierających makroilości jonów innych metali i związków chelatujących. Zsyntezowano selektywne nieorganiczne wymieniapze jonów: α-krystaliczny kwas poliantymonowy (CAA) i antymoniany metali wielowartościowych oraz zbadano ich własności sorpcyjne względem dwu- i trójwartościowych jonów strontu i europu (jako modelu aktynowców), a także jednowartościowego cezu. CAA okazał się bardzo efektywnym sorbentem dwóch pierwszych metali. Zbadano wpływ stężenia poszczególnych składników tych odpadów na sorpcję radionuklidów na CAA. Jony wapnia silnie zmniejszają sorpcję Sr(sup 2+), a EDTA w roztworach obojętnych sorpcję EU(sup 3+). Jony sodu, cytryniany i szczawiany mają niewielki wpływ na sorpcję Sr(sup 2)+ i EU(sup 3+). Radionuklidy Cs+ muszą być usuwane na innym sorbencie.

7

Interlaboratory comparison of the determination of (sup 226)Ra and (sup 228)Ra in samples simulating coal mine water

Narbutt J., Fuks L.

Nukleonika

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1998

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Vol. 43, nr 4

469-480

EN

The aim of the experiment organized by the National Atomic Energy Agency of Poland, was to carry out an interlaboratory comparison on the determination of long-lived radium isotopes in waste waters from Polish coal mines. It was expected that the experiment would allow to evaluate the proficiency of the national participants, and to eliminate possible errors in their work. 9 participating laboratories have determined the concentrations of (sup 226)Ra and (sup 228)Ra (or only (sup 226)Ra) in 6 synthetic samples containing from 0 to 300 Bq dm(sup -3) of each isotope. The results have been evaluated according to recent recommendations of IUPAC, ISO and AOAC. It is concluded that a significant majority of the results meet the proficiency criterium at the selected target accuracy. In some cases small systematic errors appear. Only a few laboratories meet more rigorous proficiency criterium. Analytical methods used for radium determination have also been evaluated.

PL

Celem eksperymentu, wykonanego na zlecenie Państwowej Agencji Atomistyki, było porównanie wyników oznaczeń stężeń długożyciowych izotopów radu w zasolonych wodach odpadowych z polskich kopalni węgla przez krajowe laboratoria radiometryczne. Oczekiwano, że eksperyment umożliwi ocenę jakości pracy poszczególnych zespołów i przyczyni się do wyeliminowania ewentualnych błędów. W międzylaboratoryjnym eksperymencie porównawczym wzięło udział 9 laboratoriów, które oznaczyły stężenia (sup 226)Ra i (sup 228)Ra (niektóre tylko (sup 226)Ra) w 6 modelowych próbkach zawierających od O do 300 Bą dm(sup -3) każdego izotopu. W pracy dokonano oceny wyników eksperymentu zgodnie z nowymi zaleceniami lUPAC, ISO i AOAC. Stwierdzono, że znaczna większość nadesłanych wyników spełnia kryterium założonego poziomu wymagań. W kilku przypadkach stwierdzono wystąpienie niewielkich błędów systematycznych. Tylko niektóre laboratoria spełniają dwukrotnie ostrzejsze kryterium. Dokonano również oceny porównawczej stosowanych metod analitycznych.