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1

Elektrownia Jądrowa Cernavoda – rumuńskie doświadczenia z technologią CANDU

Nowicki Jacek

Energetyka

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2021

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nr 1

26--41

PL

W Rumunii pracuje jedyna na kontynencie europejskim Elektrownia Jądrowa Cernavoda (rum. Centrala Nucleară de la Cernavodă) wykorzystująca kanadyjską technologię reaktorów energetycznych CANDU 6. W reaktorach tego typu paliwem jest niewzbogacony uran, zaś chłodziwem i moderatorem ciężka woda. EJ Cernavoda pokrywa około 20% zapotrzebowania na energię elektryczną w krajowym systemie elektroenergetycznym Rumunii, przyczyniając się do redukcji emisji CO2 o około 10 milionów ton rocznie. Obecnie w elektrowni pracują dwa bloki jądrowe, każdy o mocy elektrycznej 706 MW, uruchomione kolejno w latach 1996 i 2007. Pierwotne plany przewidywały budowę jeszcze trzech kolejnych jednostek, z których w przyszłości ostatecznie powstać mają jeszcze dwie. W artykule opisano historię powstania EJ Cernavoda i jej dotychczasową eksploatację. Obszernie scharakteryzowano kanadyjską technologię reaktorów energetycznych CANDU.

EN

Cernavoda Nuclear Power Plant (Centrala Nucleară de la Cernavodă) in Romania – using the Canadian technology of power reactors CANDU 6 – is the only one of this type working on the European continent. In such reactors the fuel is natural uranium and heavy water works as the coolant and the moderator. NPP Cernavoda covers about 20% of electric energy demand in the Romanian national power system, contributing to the CO2 emission reduction by around 10 million tonnes per year. At present, there are two nuclear units (of 706 MW capacity each) working in the plant, commissioned in the years 1996 and 2007 respectively. It was originally planned to build three more units but finally it was decided to build only two in the future. Presented is the history of how the NPP Cernavoda originated and its up to now conducted operation. Described is extensively the Canadian technology of CANDU power reactors.

2

Isotopic composition of precipitation in Poland: a 44-year record

Duliński Marek, Różański Kazimierz, Pierchała Anna, Gorczyca Zbigniew, Marzec Michał

Acta Geophysica

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2019

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Vol. 67, no. 6

1637--1648

EN

Isotopic composition of precipitation (2H/1H and 18O/16O isotope ratios, tritium content) is nowadays widely used in numerous applications of environmental isotopes—most notably in hydrology, climatology and biogeochemistry. Here we present a long record (44 years) of stable isotope composition and tritium content in monthly precipitation available for the Krakow station (southern Poland). Krakow is the only site in Poland for which long-term record of the isotopic composition of monthly precipitation is available. The tritium data are discussed here in the context of generally declining levels of bomb tritium in the global atmosphere and growing influence of technogenic emissions of this isotope. Two aspects of temporal variability of stable isotope composition of precipitation collected in Krakow are discussed here: (i) seasonality and (ii) interannual changes of δ18O and δ2H signal. Whereas the seasonality of stable isotope signal is generated mainly by seasonally varying the degree of rainout of air masses bringing moisture from the source regions (subtropical Atlantic Ocean) to the centre of the European continent, the North Atlantic Oscillation seems to govern interannual changes of δ18O and δ2H on the decadal timescale. Progressing warming of the local atmosphere, in the order of 1.8 °C in the past four decades, leaves its imprint in stable isotope signal measured in Krakow precipitation; the slope of isotope–temperature relationship is in the order of 0.50‰/°C for δ18O and 3.5‰/°C for δ2H.

3

Deuterium isotope effects in oxidation of dopamine by tyramine oxidase

Pająk M., Byszewska W., Kańska M.

Nukleonika

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2013

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Vol. 58, No. 2

255--259

EN

We report the studies on the mechanism of oxidation of dopamine (DA) to 3’,4’-dihydroxyphenylacetaldehyde (DOPAL) by enzyme tyramine oxidase (EC 1.4.3.6) using kinetic isotope effects (KIE) and solvent isotope effects (SIE) methods. For kinetic studies, the selectively deuterium labelled isotopologues of dopamine, i.e., [(1R)-2H]-, and [(1S)- -2H]-DA were used. The numerical values of KIE’s for the (1R)- and (1S)-isotopologues of dopamine in the enzymatic oxidation of DA to DOPAL were determined using the non competitive spectrophotometric method. Also, the SIE’s for this reaction carried out in heavy water were obtained spectrophotometrically. Some mechanistic details of enzymatic oxidation of DA to DOPAL were discussed.

4

Deuterium isotope effects in oxidation of dopamine and norepinephrine catalyzed by horseradish peroxidase

Byszewska W., Pająk M., Kańska M.

Nukleonika

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2013

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Vol. 58, No. 4

475--479

EN

Deuterium kinetic isotope effects (KIE’s) in the reaction of oxidation of dopamine (DA) catalyzed by the enzyme horseradish peroxidase (HRP, EC 1.11.1.7) was determined using a non-competitive spectrophotometric method. For kinetic studies, the deuterium ring labelled isotopomer [2’,5’,6’-2H3]-dopamine was synthesized using acid catalyzed isotopic exchange between authentic dopamine and heavy water. Deuterium solvent isotope effects (SIE’s) for dopamine and norepinephrine were determined separately for the enzymatic oxidation carried out in the presence or absence of hydrogen peroxide. Some mechanistic details of enzymatic oxidation of dopamine and norepinephrine to corresponding catecholchromes catalyzed by HRP were discussed.

5

Enzymatic reductive amination of p-hydroxy- and phenylpyruvic acids as a method of synthesis of L-tyrosine and L-phenylalanine labelled with deuterium and tritium

Pałka K., Kańska M.

Nukleonika

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2012

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Vol. 57, No. 3

383-387

EN

We report the synthesis of isotopomers of L-phenylalanine and L-tyrosine selectively labelled with hydrogen isotopes in the 2-position of the side chain. The deuterium or tritium label was introduced using reductive amination activity of enzyme L-phenylalanine dehydrogenase (EC 1.4.1.20). This way p-phenylpyruvic acid was converted into [2-2H]-, [2-3H]-, and doubly labelled [2-2H/3H]-isotopomers of L-phenylalanine, using deuteriated, tritiated, and mixed (DTO) incubation media, respectively. Similarly, p-hydroxyphenylpyruvic acid was converted into [2-2H]-, [2-3H]-, and [2-2H/3H]-L-tyrosine. Deuterium labelled isotopomers of L-phenylalanine and --tyrosine can be used as markers in the investigation of abnormal metabolism of these amino acids observed in patients with inborn genetic diseases such as phenylketonuria and tyrosinemia.

6

Analysis of Deuterium Permeation through Pd81Pt19 Alloy at Stress Conditions

Dudek D.

Polish Journal of Chemistry

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2008

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Vol. 82, nr 10

1941-1947

EN

The permeation of deuterium through Pd81Pt19 membrane at stress conditions was in vestigated at constant temperature T = 278.2 K in pressures up to 900 hPa(D2). The permeation curves were determined at different initial and boundary conditions in experimental system. The deuterium fluxes were calculated by fitting experimental points with a straight lines in the stationary parts of permeation curves. It has been showed that the deuterium permeation through the Pd81Pt19 mem brane is changed by stresses created in processes of metal lattice expansion.

7

Stable isotope deuterium as a natural tracer of mixing processes in rivers

Palige J., Ptaszek S., Zimnicki R., Chmielewski A. G., Wierzchnicki R.

Nukleonika

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2008

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Vol. 53, No. 2

63-67

EN

The possibility of application of naturally existing differences in isotope contents 18O/16O, 2H/1H in waters for investigation of transport and mixing of various waters in the tributary-river system is presented. Experiments carried out on the Bug-Narew rivers-Zegrze Lake and the BugoNarew-Vistula rivers systems have indicated that the hydrogen isotope ratio 2H/1H can be used as an intrinsic tracer of natural mixing processes occurring in rivers. The IRMS methodology was used for isotope ratio measurement of water samples. The degrees of water mixing as a function of distance from the confluence point of rivers were determined. The obtained results indicate that in water systems where the natural differences in ?2H are higher than 5‰ this technique can replace the time-consuming and expensive dye (or radiotracer) dispersion tests for evaluation of pollutant transport in rivers.

8

Synthesis of Deuterium, Tritium and 14-Carbon Labelled Isotopomers of L-DOPA

Kozłowska M., Kańska M.

Polish Journal of Chemistry

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2007

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Vol. 81, nr 10

1763-1763

EN

The synthesis of five isotopomers of L-DOPAlabelled selectivelywith deuterium, tritium and 14C is reported. The isotopomers of L-tyrosine, the intermediate substrates for this synthesis, were obtained using chemical and enzymatic methods. Selectively labelled isotopomers of L-tyrosine were hydroxylated respectively to [3R-3H]-L, [5-2H]-L, [2 ,6 -2H2]-L, doubly labelled [5-2H/3H]-L, and [1-14C]-L-DOPA using activity of enzyme tyrosine (EC 1.14.18.1) isolated from mushrooms.

9

Contribution of isotopic tracing of hydrogen with deuterium and tritium to H-induced environmental degradation of materials

Chene J.

Advances in Materials Science

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2007

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Vol. 7, nr 1(11)

113-123

EN

The isotopic tracing of hydrogen with deuterium or tritium is essential for a quantitative analysis of H-induced environmental degradation of materials. Considering the future development of hydrogen as an energy vector, a wide range of materials is concerned (metals and alloys, concrete, glasses). Whereas large perspectives are open for the development of various techniques associated with ion beam analysis applied to the profiling and maping of deuterium, the use of tritium with the related techniques appears to be the only way to investigate the crucial question of the transport of hydrogen by moving defects and the consequence on the degradadation on the material properties.

10

Isotope effects on selected physicochemical properties of nitromethane and 1-pentanol

Makowska A., Szydłowski J.

Nukleonika

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2006

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Vol. 51,suppl.2

81-85

EN

Densities, kinematic viscosities, speed of sound and refractive indices of nitromethane and 1-pentanol and their deuterated derivatives CD3NO2 and C5H11OD were measured. The data obtained allowed to calculate molar volumes, dynamic viscosities, isentropic compressibilities and isobaric thermal expansion. Deuterium isotope effect on the selected physicochemical properties of both nitromethane and 1-pentanol has been determined. Large isotope effects characterizing density, viscosity and speed of sound are observed for nitromethane and much smaller for 1-pentanol. Isotope effects on molar volume are small both for nitromethane and 1-pentanol, but of the opposite sign. These observations are in agreement with the expectations.

11

D(3He,p)4He and D(d,p)3H fusion in a small plasma focus operated in a deuterium helium-3 gas mixture

Springham S., Sim T., Rawat T., Lee P., Patran A., Shutler P., Tan T., Lee S.

Nukleonika

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2006

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Vol. 51, nr 1

47-53

EN

Abstract A 3 kJ plasma focus was operated with a 3He-D2 gas mixture, with partial pressures in the ratio of 2:1, corresponding to an atomic number ratio of 1:1 for 3He and D atoms. The fusion reactions D(3He,p)4He and D(d,p)3H were measured simultaneously using CR-39 polymer nuclear track detectors placed inside a pinhole camera positioned on the forward plasma focus axis. A sandwich arrangement of two 1000 mi m thick CR-39 detectors enabled the simultaneous registration of two groups of protons with approximate energies of 16 MeV and 3 MeV arising from the D(3He,p)4He and D(d,p)3H reactions, respectively. Radial track density distributions were obtained from each CR-39 detector and per-shot average distributions were calculated for the two groups of protons. It is found that the D(3He,p)4He and D(d,p)3H proton yields are of similar magnitude. Comparing the experimental distributions with results from a Monte Carlo simulation, it was deduced that the D(3He,p)4He fusion is concentrated close to the plasma focus pinch column, while the D(d,p)3H fusion occurs relatively far from the pinch. The relative absence of D(d,p)3H fusion in the pinch is one significant reason for concluding that the D(3He,p)4He fusion occurring in the plasma focus pinch is not thermonuclear in origin. It is argued that the bulk of the D(3He,p)4He fusion is due to energetic 3He2+ ions incident on a deuterium target. Possible explanations for differing spatial distributions of D(3He,p)4He and D(d,p)3H fusion in the plasma focus are discussed.

12

Kinetic Isotope Effect in Hydrogen Isotope Exchange Between Hydrogen Sulphide or Thiol and Alcohol in Gas and Solution

Wawer A., Szydłowski J.

Polish Journal of Chemistry

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2002

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Vol. 76 / nr 1

117-121

EN

The kinetic parameters of the tritium exchange between H2 * S(D2 * S) or MeSH*(MeSD*) and MeOH(MeOD) vapours on PTFE and glass surface were measured. The *HH/*DD kinetic isotope effects are significantly lower than those for the reaction of phosphines with methanol. The kinetics of deuterium exchange between ButSH and EtOD in solutions of C6D12 and CD3CN had been studied and HH/DD isotope effect was evaluated. It appeared to be smaller than that in the vapours. These results suggest that contrary to the exchange reactions in phosphine, the elementary reaction of HH-transfer in four center transition state is not the rate limiting step and H-bond formation as well as diffusion controlled processes should be taken into account.

13

Natural stereospecific hydrogen isotope transfer in alcohol dehydrogenase-catalysed reduction

Zhang B., Pionnier S.

Nukleonika

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2002

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Vol. 47,suppl.1

29-31

EN

The enantiomeric purity of natural alfa-monodeuterated enantiomers, (R) and (S) ethanol-1-d1, in the alcohol produced by sugar fermentation with yeast was studied by 2H NMR using their esters derived from optical mandelic acid. The results of isotope tracing experiments show that the transfer pathways of the two enantiotopic hydrogens of the methylene group are different. It was observed that (S)-deuterium comes only from the medium water. The (R)-deuterium transfered by NADH in alcohol dehydrogenase reduction of the acetaldehyde is of complex origin. Some of them originates from carbon bound hydrogen of the sugar, especially from C(4) position of glucose and most of them comes from water. Only a small portion of the NADH deuterium is incorporated indirectly from water through enzyme catalysed exchange between the pro-S site of NADH and flavin. When a carbonyl compound (ethyl acetoacetate) was reduced under the same conditions during the alcoholic fermentation, among the NADH-transfered deuterium, only a small portion comes from water while most comes from the unexchangeable positions of the glucose.

14

Influence of the photosynthetic pathway on the hydrogen isotopic profile of glucose

Zhang B., Billault I., Li X., Mabon F., Remaud G., Martin M.

Nukleonika

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2002

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Vol. 47,suppl.1

63-65

EN

The SNIF-NMR method (site-specific natural isotope fractionation studied by Nuclear Magnetic Resonance) was used to examine the isotopic profile of glucoses derived from plants with different photosynthetic pathways. It is shown that the type of photosynthetic metabolism, either C3 (beet-root, orange, grape), C4 (maize, sugar-cane) or CAM (pineapple), exerts a strong influence on the deuterium distribution in the sugar molecules. The isotopic profile also depends, secondarily, on the physiological status of the precursor plant. Consequently, the isotopic fingerprint of glucose may be a rich source of information in mechanistic comparisons of metabolic pathways. Moreover, from an analytical point of view, it may provide complementary criteria with respect to the ethanol probe for origin inference of sugars.

15

Deuterium isotope fractionation between ortho-alkyl substituted phenols and t-butylthiol in oxygen bases

Wawer A., Jelińska-Kazimierczuk M., Szydłowski J.

Polish Journal of Chemistry

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1998

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Vol. 72, nr 3

618-626

EN

Equilibrium isotope effect in the exchange reaction of deuterium between phenol (P), 2-isopropylphenol (IPP), 2,6-diisopropylphenol (DIPP), 2,6-ditertbutyl phenol (DTBP) and tertbutylthiol (TBT) has been studied at 298 K. The fractionation factors (alpha) have been measured in cyclohexane and carbon tetrachloride solution and in a few oxygen bases: acetone, 1,4-dioxane, ethyl formate, ethyl ether, tetrahydrofurane, N,N-dimethylformamide, dimethylsulphoxide and hexamethylphosphoramide. Using chemical shifts of phenol OH protons, the thermodynamic parameters of complex formation with the oxygen bases have been determined. The experimental data show that ln alpha correlates with the formation enthalpy of the phenol-oxygen base complex in DIPP-TBT-base system but there is no simple correlation in IPP-TBT-base system. Futhermore it was found that in DTBT-TBT-base system ln alpha depends linearly on the basicity of the (solvent DN parameters). On the other hand, ln alpha correlates with acidic parameters of the solvents (AN) in IPP-TBT-base and P-TBT-base systems. All above correlations are explained by taking into account two competition processes: selfassociation of phenol molecules and their solvation by oxygen bases.