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1

Radiological characterization of the phosphate deposit in Al-Jalamid phosphate mining area, Saudi Arabia

Alhawsawi Abdulsalam M., Shababa E. I., Qutub Maher M. T., Banoqitah Essam M., Kinsara A. A.

Nukleonika

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2021

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Vol. 66, No. 1

35--44

EN

It is a known fact that phosphate rocks have high levels of natural radioactivity due to the presence of large concentrations of radionuclides. This work aims to estimate radiation exposure and dose levels at Al-Jalamid site in northern Saudi Arabia. Al-Jalamid area is one of the largest reserves of phosphate worldwide. Ma’aden, a Saudi Government public company, owns the mine and is responsible for all mining activities. Phosphate and soil samples collected from Al-Jalamid phosphate mining area have been analysed for their uranium and thorium content by an α-spectrometer using radiochemical techniques. The quantity of radon gas was measured both in groundwater and in the atmosphere (indoor and outdoor) at the site using a portable radiation survey instrument. Groundwater samples collected from wells surrounding the mining area were analysed using a liquid scintillation counter in addition to an α-spectrometer. Finally, it is found that phosphate rock concentrate products cannot be utilized economically based on the standards set by the International Atomic Energy Agency (IAEA), since the average activity concentration does not reach the limit set by IAEA and hence are not commercially feasible.

2

Numerical modelling of modular high-temperature gas-cooled reactors with thorium fuel

Oettingen Mikołaj, Cetnar Jerzy

Nukleonika

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2021

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Vol. 66, No. 4

133--138

EN

The volumetric homogenization method for the simplified modelling of modular high-temperature gas-cooled reactor core with thorium-uranium fuel is presented in the paper. The method significantly reduces the complexity of the 3D numerical model. Hence, the computation time associated with the time-consuming Monte Carlo modelling of neutron transport is considerably reduced. Example results comprise the time evolutions of the effective neutron multiplication factor and fissionable isotopes (233U, 235U, 239Pu, 241Pu) for a few configurations of the initial reactor core.

3

Concentrations of Natural Radionuclides (40K, 226Ra, 232Th) at the Potash Salts Deposit

Menshikova Elena, Perevoshchikov Roman, Belkin Pavel, Blinov Sergey

Journal of Ecological Engineering

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2021

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Vol. 22, nr 3

179--187

EN

Specific activity of natural radionuclides 226Ra, 232Th and 40K was measured by gamma spectrometry in samples of soil and bottom sediments of rivers on the territory of potassium salt deposit development in order to collect information on radionuclide distribution. According to the results of examinations, the range of 226Ra, 232Th and 40K activity values in soils and bottom sediments of the territory of influence was <2.17–19.7 Bq/kg, <2.5–20.5 Bq/kg, 123–500 Bq/kg. Migration of the studied radionuclides is limited to 2 km zone. The results obtained provide useful information on the levels of naturally occurring radionuclides in the zone of influence of mining objects and are of interest for a comparative evaluation of the impact of salt mining on the radiation environment of the territory.

4

Badania nad torowym cyklem paliwowym w Akademii Górniczo-Hutniczej

Gajda Paweł, Oettingen Mikołaj

Postępy Techniki Jądrowej

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2019

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z. 2

14--17

PL

Pierwiastek tor może zostać wykorzystany jako alternatywne paliwo dla energetyki jądrowej. Posiada on szereg zalet, które świadczą o jego użyteczności w jądrowym cyklu paliwowym m.in. jego koncentracja w naturze jest od 3 do 5 razy większa niż koncentracja uranu a zużyte torowe paliwo jądrowe charakteryzuje się mniejszą długotrwałą radiotoksycznością niż zużyte paliwo uranowe. Badania nad torowym cyklem paliwowym prowadzone są również w Polsce. W Katedrze Energetyki Jądrowej, Wydziału Energetyki i Paliw Akademii Górniczo-Hutniczej im. Stanisława Staszica (AGH) w Krakowie znajduje się unikatowy w skali Polski zestaw Th-Pb pozwalający na prowadzenie prac badawczo-rozwojowych nad paliwem torowym.

EN

Thorium can be used as an alternative fuel for nuclear power generation. It presents many advantages over uranium, which shows its usability in the nuclear fuel cycle. Its concentration in nature is about 3-5 times larger than concentration of uranium. In addition, the long-term radiotoxicity of the spent thorium fuel is significantly lower than the radiotoxicity of the spent uranium fuel. The research on thorium fuel cycle is also performed in Poland. Department of Nuclear Energy, Faculty of Energy and Fuels of AGH University of Science and Technology in Krakow owns unique in Poland Th-Pb fuel assembly dedicated for research on thorium fuel.

5

Hydrometallurgical removal of uranium and thorium from Ethiopian tantalite ore

Cheru Mulugeta Sisay, Albertodel Rosario Alberto Velázquez, Yimam Abubeker, Tadesse Bogale, Berhe Gebreyohannes Goitom

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 2

448--457

EN

This study focused on the leaching of uranium and thorium from a high grade Ethiopian tantalite ore using sulfuric acid. The effects of variables such as acid concentration, temperature and leaching time were studied. In general, the leaching efficiency of uranium increases with increasing temperature from 100 to 300°C whereas the opposite trend was observed for thorium. The amount of uranium leached increased from 69.1% at contact time of 1 hr to 88.6% when the tantalite ore was leached for 3 hrs. On the other hand, for the experiments conditions considered in this study, the leaching behavior of uranium and thorium did not change significantly with varying sulphuric acid concentration from 70 to 90 wt%. Overall, the highest dissolution of uranium and thorium were achieved at 100°C, 70 wt% H2SO4 concentration and 1 hr contact time.

6

Seasonal variations in the abundance and sinking flux of biogenic silica in Daya Bay, northern South China Sea

Zhao Xiufeng, Yang Weifeng, Ma Haoyang, Li Junjie, Chen Min, Fang Ziming, Zhang Xiao, Zeng Jian, Qiu Yusheng, Zheng Minfang

Oceanologia

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2019

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No. 61 (2)

239--251

EN

Coastal seas account for > 50% of the biogenic silica (BSi) production in marine environments. However, BSi sinking is poorly understood. Here, seasonal variations in the abundance and sinking flux of BSi were investigated in Daya Bay, in the northern South China Sea. The highest BSi concentrations occurred in summer, averaging 8.04 ± 5.48 μmol L-1 (±SD), followed by autumn (5.51 ± 3.11 μmol L-1) and spring (3.76 ± 3.06 μmol L-1). The lowest BSi concentration of 2.93 ± 1.34 μmol L-1 was observed in winter. Based on234Th/238U disequilibria, the average BSi sinking fluxes were 7.08 ± 8.62, 10.01 ± 13.95, and 8.30 ± 13.06 mmol Si m-2 d-1 in spring, summer, and autumn, respectively. The lowest flux of 4.19 ± 3.98 mmol Si m-2 d-1was measured in winter. Together with nitrogen fluxes, the Si:N sinking ratios were 0.8:1.0, 1.5:1.0, 1.6:1.0, and 1.4:1.0 in spring, summer, autumn, and winter, respectively, indicating that particle sinking induces the faster removal of Si compared to N in Daya Bay.

7

Modelling of the reactor cycle cost for thorium-fuelled PWR and environmental aspects of a nuclear fuel cycle

Oettingen Mikołaj

Geology, Geophysics and Environment

|

2019

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Vol. 45, no. 3

207--217

EN

The paper presents the methodology applied to the cost modelling of the uranium-thorium nuclear reactor cycle for PWR reactors as well as brief introduction to the environmental impact of the nuclear fuel cycle. The reactor core contains seed uranium fuel and blanket thorium fuel. In such a cycle, energy is produced in the fission of 235U included in the fresh fuel and in the fission of 233U bread from the fertile 232Th. A modified methodology developed by the OECD Nuclear Energy Agency was used for the reactor cycle cost modelling. The method is based on the levelized lifetime cost methodology for a reactor cycle, which is directly related to the heavy metal mass balance. Contrary to the case of uranium-fuelled nuclear reactors, the cost modelling includes the additional cash flow for thorium fuel. The abundance of thorium in the Earth’s crust is about 3–5 times larger than that of uranium, which suggests its promising potential as a nuclear fuel. However, this needs to be proved economically.

8

Tor a bezpieczeństwo energetyczne. Reaktory torowe

Stępień M., Gurgacz S., Niewiński G.

Rynek Energii

|

2018

|

Nr 4

79--84

PL

Artykuł porusza kwestię wykorzystania toru jako materiału rodnego, zdolnego do powielania paliwa jądrowego. Opracowanie zawiera charakterystykę tego pierwiastka, opis cyklu torowego oraz rozlokowanie toru na świecie. Prze-analizowano możliwości zastosowania toru do produkowania energii oraz technologie jądrowych reaktorów prędkich powielających zawierających tor.

EN

The article focuses on the use of thorium as a fertile material, which is able to breed of nuclear fuel. It contains a description of this chemical element, thorium fuel cycle and its deployment on the Earth. It examines the possibilities of thorium’s application to power generation and fast breed reactor technologies.

9

Solubility of Eskisehir thorium/rare earth ores in sulphuric and nitric acids

Kursun I., Tombal T. D., Terzi M.

Physicochemical Problems of Mineral Processing

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2018

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Vol. 54, iss. 2

476--483

EN

Nuclear energy is considered as one of the most important energy resources in the world. Thorium (Th) has a significant potential to be used in electricity production by nuclear energy since its existence is not depended on the presence of another radioactive elements, and it has larger potential reserves than uranium. Bastnaesite ((Ce, La)CO3F) is one of the minerals from which Th can be economically extracted. In this study, solubility of bastnaesite containing ore obtained from Eskisehir, Turkey was investigated by leaching with H2SO4 and HNO3 in terms of leaching performance of thorium and some rare-earth elements (Ce, Nd, La). In this context, representative samples were taken from three different areas in Eskisehir-Kizilcaoren region, and a composite sample was prepared to be used for the leaching experiments. The effects of several parameters such as the solid ratio, leaching time, acid amount and pulp temperature, on dissolution efficiencies of Th, Nd, Ce and La was investigated. The best results were obtained using 3.42 mol/dm3 HNO3, solid–to–liquid ratio of 35%, 120 min leaching time and 60 oC temperature. Under these optimum conditions, the dissolution efficiencies of Th, Ce, Nd, and La were obtained as 94%, 82%, 77% and 70%, respectively.

10

Monte Carlo modelling of Th-Pb fuel assembly with californium neutron source

Oettingen M., Stanisz S.

Nukleonika

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2018

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Vol. 63, No. 3

87--91

EN

This paper describes the methodology developed for the numerical reconstruction and modelling of the thorium-lead (Th-Pb) assembly available at the Department of Nuclear Energy, Faculty of Energy and Fuels, AGH University, Krakow, Poland. This numerical study is the first step towards integral irradiation experiments in the Th-Pb environment. The continuous-energy Monte Carlo burnup (MCB) code available on supercomputer Prometheus of ACK Cyfronet AGH was applied for numerical modelling. The assembly consists of a hexagonal array of ThO2 fuel rods and metallic Pb rods. The design allows for different arrangements of the rods for various types of irradiations and experimental measurements. The intensity of the fresh neutron source intended for integral experiments is about 108 n/s, which corresponds to the mass of about 43 μg 252Cf. The source was modelled in the form of Cf2O3-Pd cermet wire embedded in two stainless steel capsules.

11

Features of distribution of uranium and thorium in red mud

Gu H., Wang N., Yang Y., Zhao C., Cui S.

Physicochemical Problems of Mineral Processing

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2017

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Vol. 53, iss. 1

110--120

EN

Natural radioactive elements such as uranium and thorium restrict the use of red mud as building materials or additives, and may cause environmental problems. The distribution features of U and Th in red mud was studied from micro and macro analysis, using EPMA, LA-ICP-MS, and methods of mineralogy and beneficiation. Based on the micro-area scanning analysis, main chemical compositions in red mud, such as Ca, Al, Si, Na, and K are dispersive while Fe and Ti mainly tend to concentrate in granular phases. Based on the in-situ analysis, the distribution of main elements and most trace elements in micro-zone of red mud was homogeneous. In micro-zone area, the variation tendency of thorium content was similar with Y in red mud samples. By means of the methods of mineralogy and beneficiation, red mud samples were separated into different fractions. U and Th tend to be enriched in the low density fraction of the red mud. Th presented a high concentration in the finest particle size fractions of the red mud. Neither U or Th was regularly distributed in various magnetic red mud fractions. Thorium fingerprint peaks were determined in perovskite by EDX under TEM, which is proposed to be one of the radioactivity sources in Bayer red mud.

12

Natural background gamma radiation in the urban space of Walbrzych

Nowak K.

Proceedings of ECOpole

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2016

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Vol. 10, No. 1

47--56

EN

Walbrzych is the second most populous city of dolnoslaskie voivodeship, with the population of over 117 000 inhabitants. It is one of the largest cities within the Sudety Mountains with the area of approximately 85 km2. From the geological point of view it is situated at the junction of three units: the Gory Sowie Massif, the Swiebodzice Basin and the Intra-Sudetic Basin. Each of this unit consists of various rocks which are characterised by various natural radionuclides content, resulting in various gamma dose rates in air within Walbrzych area. The landscape of the city largely is formed by an anthropogenic activity, mainly coal mining. Within the city there are thirty two heaps of wastes after the coal mining. The gamma spectrometric research of natural background gamma radiation in the urban space of Walbrzych was carried out. In situ measurements were performed by means of portable gamma spectrometer RS 230 with a BGO detector and dimensions of 259 mm × 81 mm × 96 mm. The device displays potassium K [%], equivalent uranium eU [ppm] and equivalent thorium eTh [ppm] contents, as well as absorbed gamma dose rate in air at the height of 1 meter generated by these radionuclides [in nGy/h]. The investigations were divided into two stages. In the first one, the content of K, eU and eTh in various types of rocks was examined. Measurements were performed on 14 outcrops of various aged rocks within all the three units (from Proterozoic gneisses of the Gory Sowie Massif to Pleistocene sands and gravels covering the Swiebodzice Basin) and on a heap. In the second stage the spatial distribution of natural radionuclides and gamma dose rate within the city was examined. Forty measurements were performed in the nodes of regular grid with the mesh size of 1.5 km. Taking into account that gamma dose rate in air mostly is formed by radionuclides present in the top 30-centimetres ground surface, the type of material covering the ground in measurement points was noted. Performed investigations showed that among rocks occurring within Walbrzych city, late Carboniferous trachyandesites, outcropping in the old quarry in Podgorze II district (the Intra-Sudetic Basin), were the most radioactive. The mean content of K, eU and eTh was 3.8%, 4.0 and 18.3 ppm, respectively which generated absorbed gamma dose rate equal to 121.2 nGy/h. Late Carboniferous conglomerates and sandstones of the Glinik Formation (the Intra-Sudetic Basin) are characterised by the lowest radioactivity. The mean content of K, eU and eTh was 0.6%, 1.5 and 5.1 ppm, respectively which generated absorbed gamma dose rate equal to 29.6 nGy/h. The analysis of spatial distribution of absorbed gamma dose rate showed that Srodmiescie district and the vicinity of Ksiaz Castle are characterised by the highest natural background gamma radiation. Absorbed dose rates with values of over 100 nGy/h were noted in places where the ground was covered by granite cobblestone. The lowest natural background gamma radiation was observed in points situated on the outskirts of the city, in places with relatively natural soils.

PL

Wałbrzych jest drugim najludniejszym miastem województwa dolnośląskiego, liczącym ponad 117 tys. mieszkańców. Jest jednym z największych miast Sudetów, o powierzchni ok. 85 km2. Pod względem geologicznym leży na styku trzech jednostek geologiczno-strukturalnych: bloku sowiogórskiego, depresji Świebodzic oraz niecki śródsudeckiej. Każdą z tych jednostek budują różnorodne skały, charakteryzujące się zróżnicowaną zawartością naturalnych pierwiastków promieniotwórczych, co sprawia, że moc dawki promieniowania gamma w powietrzu pochodząca od naturalnych radionuklidów rozproszonych w skałach podłoża i glebie waha się w szerokich granicach na terenie Wałbrzycha. Krajobraz miasta w dużej mierze ukształtowany jest przez działalność człowieka. Pozostałością po eksploatacji węgla kamiennego są 32 hałdy. Przeprowadzono gamma spektrometryczne badania naturalnego tła promieniotwórczego w przestrzeni miejskiej Wałbrzycha. Pomiary in situ były wykonywane przy pomocy przenośnego spektrometru gamma RS 230 o wymiarach 259 mm × 81 mm × 96 mm, wyposażonego w detektor BGO. Urządzenie podaje zawartość potasu K [%] oraz równoważne zawartości uranu eU [ppm] i toru eTh [ppm], a także moc dawki pochłoniętej w powietrzu na wysokości 1 metra generowanej przez te radionuklidy [nGy/h]. Badania składały się z dwóch etapów. W pierwszym zbadano zawartość K, eU i eTh w różnych typach skał podłoża, wykonując pomiary na 14 wychodniach różnowiekowych skał w obrębie trzech jednostek geologiczno-strukturalnych (od proterozoicznych gnejsów bloku sowiogórskiego po plejstoceńskie piaski i żwiry pokrywające depresję Świebodzic) oraz na hałdzie odpadów powęglowych. W drugim etapie zbadano przestrzenny rozkład zawartości naturalnych radionuklidów oraz mocy dawki promieniowania gamma na terenie miasta, wykonując 40 pomiarów w węzłach regularnej siatki o wielkości oczek 1,5 km. Uwzględniając fakt, że moc dawki promieniowania gamma w powietrzu kształtują głównie radionuklidy znajdujące się w 30-centymetrowej wierzchniej warstwie podłoża, zanotowano rodzaj pokrycia gruntu w badanych punktach. Przeprowadzone badania wykazały, że wśród skał występujących na terenie Wałbrzycha najbardziej radioaktywne są późnokarbońskie trachyandezyty odsłaniające się w starym kamieniołomie w dzielnicy Podgórze II (niecka śródsudecka). Zawartość K, eU i eTh wynosi średnio 3,8%, 4,0 i 18,3 ppm, odpowiednio, generując moc dawki pochłoniętej w powietrzu równą 121,2 nGy/h. Najniższą radioaktywnością charakteryzują się późnokarbońskie zlepieńce i piaskowce formacji z Glinika (niecka śródsudecka). Zawartość K, eU i eTh wynosi średnio 0,6%, 1,5 i 5,1 ppm, odpowiednio, generując moc dawki pochłoniętej w powietrzu równą 29,6 nGy/h. Analiza przestrzennego rozkładu mocy dawki pochłoniętej wykazała, że najwyższym tłem promieniowania gamma charakteryzuje się dzielnica Śródmieście oraz rejon zamku Książ. Moc dawki pochłoniętej o wartości ponad 100 nGy/h odnotowano w miejscach, w których grunt pokryty został kostką granitową. Najniższe tło promieniowania gamma zaobserwowano natomiast w punktach znajdujących się na obrzeżach miasta, w miejscach występowania względnie naturalnej gleby.

13

Recovery of trace elements with uranium and thorium from yatagan thermal power plant fly ashes by leaching

Kursun I., Ozkan S. G., Kilic A., Terzi M., Enkhtaivan N.

Physicochemical Problems of Mineral Processing

|

2016

|

Vol. 52, iss. 2

588--596

EN

In this paper, characterization of fly ashes obtained from the Yatagan Thermal Power plant, Mugla, Turkey was performed in order to determine their radioactive element contents, especially uranium and thorium. The representative fly ash samples were subjected to hydrochloric acid (HCl) leaching considering solid concentration, acid dosage, leaching time and temperature in order to reach certain uranium and thorium recoveries. The obtained results showed that the optimum conditions for leaching tests were: 30% solid concentration, 2.36 mmol/dm3 HCl addition, 240 min leaching time and 40 oC temperature. Dissolution efficiencies for uranium and thorium from the Yatagan Thermal Power Plant fly ashes were calculated as 90.12 and 81.18%, respectively.

14

Thoron emanation and exhalation of Slovenian soils determined by a PIC detector-equipped radon monitor

Jónás J., Sas Z., Vaupotic J., Kocsis E., Somlai J., Kovács T.

Nukleonika

|

2016

|

Vol. 61, No. 3

379--384

EN

The health risk from thoron (Rn-220) is usually ignored owing to its short half-life (55.6 s), but the generated thoron decay products can cause a significant dose contribution. In this study, altogether 51 Slovenian soil samples were investigated using an accumulation chamber technique to obtain information about thoron exhalation features. The obtained (massic) thoron exhalation results varied between 6.9 and 149 mBq•kg–1•s–1 (average: 55.2 mBq•kg –1•s–1). The Th-232 content was determined using HPGe gamma spectrometry. The Th-232 activity concentration ranged between 9.3 and 161.7 Bq•kg–1 (average: 64.6 Bq•kg –1). The thoron emanation features were also calculated from the obtained results (2.9 to 21.2% with an average of 8.6%). The thoron exhalation and emanation properties were compared with the radon exhalation and emanation features determined in a previous study. It was found that there was no correlation between the radon and thoron emanation features, according to the obtained data. This can be explained by the different Ra-224 and Ra-226 distributions in the soil grains. As a result, the thoron emanation factor cannot be predicted from radon emanation and vice versa.

15

Preliminary results of spatial distribution of uranium and thorium in soil profi les near a uranium industrial site, Guangdong province, China

Wang J., Liu J., Chen Y., Song G., Chen D., Xiao T., Li H., Wang C., Jiang F.

Nukleonika

|

2016

|

Vol. 61, No. 3

367--371

EN

Four soil profiles were collected from locations with different distances (5, 50, 250 and 1000 m) from a uranium mill tailings dam, Guangdong province, China, to investigate the pollution status of the soil in mining/ milling-related areas based on the contents of uranium (U) and thorium (Th), thus to understand the impacts of uranium industrial activities to the surroundings. The U and Th concentrations were determined by inductively coupled plasma mass spectrometry (ICP-MS) after conventional HF-HNO3-HClO4 digestion procedures. The results indicate that the soils within 50 m from uranium tailing were severely contaminated; those in 250 and 1000 m soil samples were observed to be with local background level even though these in 250 m had slightly higher U/Th ratios. Uranium concentrations varied from 5.50 ± 0.27 to 160.55 ± 8.03 mg/kg, with maximum values recorded in an intermediate layer of the 5-m distance soil profile. In comparison, the concentration of Th ranged from 6.02 ± 0.30 to 84.71 ± 4.24 mg/kg, with maximum values observed in the top layer of the 1000-m distance soil profile. The U/Th ratio varied from 0.15 to 11.99 compared with 0.20, 0.22 and 0.26 of the average for Guangdong province, national China and the world, respectively. The mean U/Th of four soil profiles showed a reduction with distance from the uranium mill tailing dam, suggesting the relatively large magnitude of uranium elevation in soils within limited distances.

16

Naturally occurring radionuclides and rare earth elements in weathered Japanese soil samples

Sahoo S., Hosoda M., Prasad G., Takahashi H., Sorimachi A., Ishikawa T., Tokonami S., Uchida S.

Acta Geophysica

|

2013

|

Vol. 61, no. 4

876--885

EN

The activity concentrations of 226Ra and 228Ac in weathered Japanese soils from two selected prefectures have been measured using a γ-ray spectroscopy system with high purity germanium detector. The uranium, thorium, and rare earth elements (REEs) concentrations were determined from the same soil samples using inductively coupled plasma mass spectrometry (ICP-MS). For example, granitic rocks contain higher amounts of U, Th, and light REEs compared to other igneous rocks such as basalt and andesites. Therefore, it is necessary to understand the interaction between REEs and nature of soils since soils are complex heterogeneous mixture of organic and inorganic solids, water, and gases. In this paper, we will discuss about distribution pattern of 238U and 232Th along with REEs in soil samples of weathered acid rock (granite) collected from two prefectures of Japan: Hiroshima and Miyagi.

17

Statistical Calibration of Model Solution of Analytes

Simeonov V., Simenova P., Spasov L.

Ecological Chemistry and Engineering. S

|

2012

|

Vol. 19, nr 1

67-75

EN

A new method based on spectrophotometric-partial least-squares procedure was proposed for simultaneously determination of thorium and zirconium using SPADNS (4,5-Dihydroxy-3-(p-sulfophenylazo)- 2,7-naphthalene disulfonic acid, trisodium salt) as a color reagent. Absorbance measurements were made in the range of lambda = 541�€620 nm with 1.0 nm steps in buffered solutions at pH 3.5. The linear ranges were obtained for 0.5�€11.5 and 1.5�€14.5 �Ęg cm.3 for Th4+ and Zr4+ ions, respectively. The limits of detection were determined 0.4 and 1.2 mikrog cm.3 for thorium and zirconium, respectively. The standard deviation (n = 3) and recovery percent of 10 samples in the prediction set were obtained in the amplitude 0.22�€0.38 mikrog cm.3 and 91.3�€109.2, respectively. The proposed method was used for simultaneously determination of mentioned ions in spiked real water samples and wastewater. The results show that the method is applicable for the analysis of samples with similar matrix.

PL

Nowa metoda opiera się na procedurze spektrofotometrycznej - najmniejszych kwadratów, która została zaproponowana do rownoczesnego oznaczania toru i cyrkonu z wykorzystaniem SPADNS (kwas 4,5-Dihydroksy-3-(p-sulfofenylazo)-2,7-naftaleno disulfonowy, sol trisodowa) jako odczynnika koloru. Pomiarów absorbancji dokonano w zakresie lambda = 541�€620 nm co 1,0 nm w roztworach buforowych o pH 3,5. Liniowy zakres uzyskano przy stężeniach jonow Th4+ i Zr4+ odpowiednio 0,5�€11,5 i 1,5�€14,5 �Ęg cm.3. Granice wykrywalności dla toru i cyrkonu wynosi.y odpowiednio 0,4 i 1,2 milig cm.3. Wyznaczono odchylenie standardowe (n = 3) i procent odzysku w serii 10 probek odpowiednio w zakresie 0,22�€0,38 i 91,3�€109,2 mikrog cm.3. Proponowana metoda zosta.a zastosowana do rownoczesnego oznaczania wymienionych jonow w wzbogaconych próbkach rzeczywistych wody i ściekow. Wyniki pokazują, że ta metoda może być wykorzystywana do analizy próbek o podobnej matrycy.

18

Rozwój technologiczny w energetyce jądrowej i jego wpływ na zapotrzebowanie na surowce rozszczepialne

Chmielewski A.G.

Biuletyn Państwowego Instytutu Geologicznego

|

2010

|

nr 439 (1)

77--80

PL

W artykule w skrócie omówiono informacje dotyczące światowych zasobów surowców rozszczepialnych, w świetle rozwoju technologicznego energetyki jądrowej. Wskazano też na możliwości wykorzystania toru i podkreślono rolę zamkniętego cyklu paliwowego w dalszym rozwoju energetyki jądrowej. Przedstawiono także możliwości uzyskiwania uranu z surowców ubogich w ten pierwiastek.

EN

Data regarding worldwide fissile elements reserves from the point of view of nuclear technology development are presented in the paper. The possibilities of thorium application as a fissile fuel and role of closed cycle (fuel reprocessing) in the further nuclear power development are discussed as well. The possibility of low grade ore and waste streams for uranium recovery is presented finally.

19

Technologie energetyki jądrowej XXI wieku

Chwaszczewski S.

Polityka Energetyczna

|

2009

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T. 12, z. 2/2

43-55

PL

Wzrastające zapotrzebowanie świata na energię, a w szczególności na energię elektryczną wymaga rewizji technologii energetyki jądrowej, jako perspektywicznego źródła energii. W tym kontekście niniejsza publikacja przedstawia analizę, na ile energetyka jądrowa wpisuje się w cele zrównoważonego rozwoju oraz jaki może mieć udział w nim. Wzrastające zapotrzebowanie świata na energię, a w szczególności na energię elektryczną wymaga rewizji technologii energetyki jądrowej, jako perspektywicznego źródła energii. W tym kontekście niniejsza publikacja przedstawia analizę, na ile energetyka jądrowa wpisuje się w cele zrównoważonego rozwoju oraz jaki może mieć udział w nim.

EN

The world-wide increasing energy demand in general, and electricity demand in particular, call for a reevaluation of fission energy as a long-term energy source. In this context, a recent paper has investigated the extent to which nuclear energy is compatible with the goals of sustainable development, and how it can best contribute to them. Although present light water reactors (LWRs) are capable of covering the nuclear energy demand for many decades to come, there is a longerterm need for integrating advanced reactors, including breeder reactors, into the nuclear energy system. Important development goals for such advanced systems are environmental friendliness and resource efficiency, while accounting for sociopolitical concerns such as proliferation.

20

Występowanie pierwiastków promieniotwórczych w węglach kamiennych pochodzących z GZW, w skałach przywęglowych, w wodach kopalnianych oraz w odpadach

Olkuski T., Stala-Szlugaj K.

Gospodarka Surowcami Mineralnymi

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2009

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T. 25, z. 1

5-17

PL

W artykule przeanalizowano badania nad zawartością pierwiastków promieniotwórczych w węglu kamiennym pochodzącym z Górnośląskiego Zagłębia Węglowego. Prześledzono zachowanie się uranu, toru, izotopów radu i potasu w węglu jako surowcu mineralnym, w skałach przywęglowych, w wodach kopalnianych oraz w odpadach eksploatacyjnych i produktach spalania węgla. Sałdan (1965) zaobserwował wyraźnie pionową i poziomą strefowość ułożenia mineralizacji uranowej oraz stwierdził, że najbardziej zmineralizowane są brzeżne, zwłaszcza wschodnie strefy zbiornika sedymentacyjnego. Jęczalik (1970) zauważył, że uran w węglach koncentruje się w bardziej utlenionych składnikach substancji organicznej i osiąga maksymalne zawartości we frakcjach o ciężarze właściwym wynoszącym 1,7-2,0 g/cm3. Według Róg (2005) w sortymentach grubych i średnich stężenie radionuklidów wzrasta wraz ze wzrostem sumarycznej ilości macerałów grupy witrynitu i karbargilitu, w którym substancja mineralna współwystępuje z witrynitem. Michalik (2006) podaje, że na aktywność właściwą naturalnych izotopów promieniotwórczych w węglu wpływa ilość zanieczyszczeń oraz skład mineralny, zaś z badań petrograficznych wynika, że głównym źródłem promieniotwórczości w węglu kamiennym oraz skałach przywęglowych są skupienia wtórnych fosforanów, detrytyczny monacyt, cyrkon, ksenotym i uranothoryt. Natomiast Bojakowska i in. (2008) zaobserwowali wzrost zawartości uranu i toru od spągu do stropu serii paralicznej GZW, zaś w obrębie warstw serii limnicznej odnotowali częstą przewagę zawartości U nad zawartością Th, a w warstwach siodłowych rozpoczynających serię limniczną - najniższą zawartość tych pierwiastków. Spalanie węgla powoduje uwolnienie do atmosfery dużych ilości pyłów, które zawierają naturalne izotopy promieniotwórcze (uran, rad, tor) oraz ich produkty rozpadu. Michalik (2006) podaje, że stopień skażenia środowiska tymi radionuklidami jest ściśle powiązany z ich początkową zawartością w węglu. Stąd wynika konieczność badania tych pierwiastków w węglu i wybór takich węgli, które zawierają najniższe stężenia niepożądanych składników. Natomiast znając aktywności izotopów naturalnych w węglach i powstających z nich popiołów można zoptymalizować dobór spalanego węgla w taki sposób, aby nie prowadziło to do ponadnormatywnych skażeń środowiska naturalnego.

EN

The paper presents the survey of research conducted on the concentration of radioactive elements in hard coal from the Upper Silesian Coal Basin (USCB). The content of uranium, thorium, radium and potassium isotopes was analyzed in hard coal, (as a raw mineral material), gangue, mine waters, mining wastes and coal combustion products (fly ashes and slags). Sałdan (1965) observed the vertical and horizontal zonal distribution of the uranium mineralization. He established that the eastern margin of the coal basin is especially rich in this element. Jęczalik (1970) noticed that the uranium contained in coals concentrates in more oxidized components of the organic matter, reaching its maximum in a fraction with a specific gravity from 1.7 to 2.0 g/cm3. According to Róg (2005), for coarse- and medium-grained coal products. The concentration of radionuclides increases together with increase of total maceral content of vitrinite and carbargilite, in which mineral matter coexists with vitrinite. Michalik (2006) found that the radioactivity of coal depends on its contamination and mineral composition, and petrographical research shows that the main sources of natural radioactivity in hard coal and gangue are secondary phosphates and detrital: monazite, zircon, xenotime and uranothorite. In them, Bojakowska et al. (2008) observed that uranium and thorium contents increase from floor to roof of the USCB Paralic Series, whereas in the USCB Limnic Series uranium frequently predominates over thorium, and the lowest contents of this elements were noticed in the Saddle Strata, that begin the Limnic Series. During coal combustion process a great amount of fly ashes and aerosol particles containing natural radionuclides (uranium, radium, thorium) and products of their decay are emitted into the atmosphere. Michalik (2006) observed that the degree of environment contamination by radionuclides depends on their initial concentration in coal. For this reason it is necessary to study radioactivity of coals and to select those containing the lowest amounts of harmful components. Knowing activity of radionuclides in coal and in fly ashes, it is possible to optimize and control the amount of emitted compounds, in the way allowing to not surpassing the emission limits and preventing environment pollution.