Sürdürülebilir Kalkınma Amaçları
Yayınlar
- Conference ObjectAçık Erişim2026Neutronic and thermal-hydraulic performance analysis of a novel thorium-based fuel in dual-cooled annular assemblies for SMR applications
Rifai, Hanan; Kabach, Ouadie; Uzun, Sinem; Genç, Yasin; Uzun, Bedrettin; Amsil, Hamid; Chakir, El Mahjoub; Sadoune, Zouhair; Didi, A.; Baatout, S.
A coupled neutronic and thermal-hydraulic assessment is performed for a dual-cooled annular fuel concept applied to light-water SMR conditions. A mixed thorium-based oxide, (Th-233U-235U)O2, is evaluated against conventional UO2 and solid-pin benchmarks while sweeping the inner moderator radius (0.05-0.43165 cm) at constant fuel volume. The thorium annular cases sustain an infinite multiplication factor (kinf) of 1.002-1.003 at EOC and achieve 3-batch discharge burnups of 166.3-173.5 GWd/t, compared with 142.4 GWd/t for solid UO2. Radial peaking remains low (maximum PPF ≈ 1.056, well below the 1.65 Westinghouse-types PWR design limit). All configurations exhibit negative FTC and MTC, with stronger negative feedback at larger inner radii. Thermal-hydraulic results show smooth coolant heating and robust DNBR margins (minimum ∼ 2.3) with negligible sensitivity to inner radius. These outcomes support the feasibility of thorium-based annular fuel for SMR deployment with improved fuel utilization and preserved safety margins.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2026Coupled Neutronic and Thermal-Hydraulic Analysis of Inner Moderator Radius Effects in Dual-Cooled Annular UO2 and Thorium-Based Fuels for a LW-SMR
Kabach, Ouadie; Rifai, Hanan; Uzun, Sinem; Genç, Yasin; Amsil, Hamid; El Banni, Fadi; Uzun, Bedrettin; Chakir, El Mahjoub
This study evaluated the effect of the inner moderator radius on the neutronic and thermal-hydraulic performance of dual-cooled annular UO2 and (Th-233U-235U)O2 fuels for a light water (LW) small modular reactor (SMR) derived from the AP300™ concept. The analysis combined lattice neutronic calculations and fuel channel thermal-hydraulic modeling to assess reactivity behavior, discharge burnup, cycle length, isotopic evolution, power peaking factor, pressure drop, coolant temperature rise, and departure from nucleate boiling ratio (DNBR). The results showed that the thorium-based fuel provided better fuel utilization than UO2 over the entire investigated range of inner moderator radii. Under single-batch operation, the discharge burnup of the thorium-based fuel reached 36.96 to 38.57 gigawatt-days per metric tonne (GWd/t), whereas the UO2 cases achieved 27.14 to 35.41 GWd/t. For a three-batch strategy, the thorium-based option attained 166.3 to 170.8 GWd/t and yielded longer operating cycles. It also significantly suppressed plutonium production and higher actinide accumulations, while reducing 135Xe and 149Sm poisoning. Increasing the inner moderator radius improved fertile-to-fissile conversion in both fuel systems; however, the thorium-based fuel exhibited much smaller performance degradation across the examined range. From the thermal-hydraulic standpoint, all the cases exhibited very similar behavior, with low power peaking factors, DNBRs near 2.3, and nearly unchanged pressure drop trends. Overall, the results demonstrated that thorium-based dual-cooled annular fuel is a promising option for improving fuel cycle performance while maintaining favorable thermal-hydraulic safety margins in LW SMRs.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2026A comprehensive assessment of neutronic and thermal–hydraulic behavior of some advanced accident-tolerant fuels in solid and dual-cooled annular PWR assemblies
Kabach, Ouadie; Uzun, Sinem; Genç, Yasin; Uzun, Bedrettin; Chakir, El Mahjoub; Amsil, Hamid
Accident-tolerant fuel (ATF) concepts are being evaluated to strengthen margins without sacrificing core economics. This study compares five ATF matrices, UN (with natural and enriched nitrogen), UC, UCO, U3Si2, and UAl2, implemented in 17 × 17 solid and 13 × 13 dual-cooled annular PWR lattices. Results show that the multiplication factor decreases monotonically with burnup in both geometries, which allows the use of the linear reactivity model to predict the reactor cycle length; UAl2 and UO2 provide the longest cycles. Assembly-level radial peaking remains low (≈1.05–1.09). All fuel and moderator temperature coefficients are negative, with the strongest feedback in annular UN (Natural N). Solid pins show a single outer-rim power/Pu-239 peak; annular pins split this into two milder rims and flatten the in-pin profile. Prompt (neutron-induced) power is essentially burnup-invariant by normalization, while decay heat grows with matrix density and conversion. Thermal-hydraulic results show that the annular geometry lowers coolant heating and pressure drop and raises the minimum DNBR by ∼ 55–65% relative to solid pins under identical boundary conditions.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2025Thermal-hydraulic investigation of novel thoriumuranium fuel mixtures in advanced SMR assembly configurations
Uzun, Sinem; Genç, Yasin; Rifai, Hanan; Kabach, Ouadie; Uzun, Bedrettin; Sadoune, Zouhair; Chakir, El Mahjoub; Amsil, Hamid; El Banni, Fadi
Nuclear energy sustainability and deployment flexibility can be significantly enhanced through Small Modular Reactors (SMRs) technology. Critical to their operational success is the thorough assessment of thermal-hydraulic characteristics, especially when incorporating advanced fuel design concepts. This research conducts an extensive thermal-hydraulic analysis examining various thorium-based fuel formulations, including (Th-235 U)O2, (Th-233 U) O2, and an innovative (Th-233 U-235 U)O2 composition, benchmarked against standard UO2 fuel. The investigation encompasses both solid fuel arrangements and dual-cooled annular assembly designs, focusing on safety optimization and operational efficiency enhancement. The analysis focuses on key safety parameters, including pressure drop, coolant enthalpy, fuel centerline temperature, and Departure from Nucleate Boiling Ratio (DNBR). Results for solid fuel configurations reveal that thorium-based fuels exhibit reduced pressure drop, more efficient enthalpy distribution, lower peak fuel temperatures, and higher DNBR values compared to conventional UO2, highlighting improved thermal stability and safety margins. The (Th-233 U-235 U)O2 mixture demonstrates a balanced performance by mitigating the limitations of other thorium compositions. In annular configurations, all fuel types benefit from enhanced heat removal due to the dual cooling surfaces, resulting in further reductions in pressure drop and peak temperatures, as well as a significant increase in DNBR values. The highest DNBR, reaching up to 3.051, confirms the annular geometry’s superior safety performance against boiling crises.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2025Investigation of the Thermal Effects of MgO and ZnO Nanoparticles in a Pressurized Water Reactor Coolant with Computational Fluid Dynamics Model
Uzun, Sinem
When nanofluids are used as reactor coolants, they provide more effective heat transfer with their increase in thermal conduction properties. This plays an important role in energy production by increasing the efficiency of nuclear reactors. The present study delves into the thermal-hydraulic ramifications of utilizing nanofluids as coolants in the VVER-1000 nuclear reactor. Specifically, the thermal-hydraulic characteristics, encompassing parameters such as coolant temperature and departure from nucleate boiling ratio, were scrutinized in light of the incorporation of magnesium oxide (MgO) and zinc oxide nanoparticles. While performing these analyses, not only uranium but also thorium was used in the core as reactor fuel. Considering the emergence of thorium as a potential fuel material in nuclear technology, its inclusion in the fuel composition contributed to the originality of the research. With the addition of 0.2% MgO nanoparticles to a VVER nuclear reactor using 5% thorium dioxide (ThO2) fuel, the coolant temperature as a result of the channel flow was determined as 617.4 K (while 613.7 K for the light water). When employing thorium fuel (with an equivalent nanoparticle concentration), the maximum temperature exhibited an approximate increase of 3 deg compared to uranium fuel. With the addition of 0.2% MgO nanoparticles, the enthalpy value at the end of the channel was 1303.6 kJ/kg when using 5% ThO2 fuel, while the enthalpy value was determined as 1295 kJ/kg in 3.7% enriched UO2 fuel. As one of the most important results of the analysis, it was observed that the temperature value of the coolant increased when nanoparticles were used.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2025Innovative thorium-based fuel assemblies for LW-SMR: In-depth assembly-level neutronic analysis and safety considerations in solid and annular configurations
Rifai, Hanan; Kabach, Ouadie; Sadoune, Zouhair; Chakir, El Mahjoub; Uzun, Sinem; Amsil, Hamid; Banni, Fadi El
This study presents a comprehensive neutronic and safety evaluation of different thorium-based fuel compositions (Th-235U)O2, (Th-233U)O2, and a new proposed composition, namely, (Th-233U-235U)O2 fuel, compared to conventional UO2 in solid and dual-cooled annular assembly configurations in the context of Small Modular Reactors (SMR) applications. Results demonstrate that (Th-233U)O2 achieves the highest cycle length in both solid configurations, significantly exceeding UO2 performance. The proposed, however, (Th-233U-235U)O2 composition exhibits favorable safety characteristics, including enhanced negative temperature reactivity coefficients and favorable kinetic parameters. Annular fuel configurations also demonstrate superior thermal performance with centerline temperature reductions of approximately 50 °C compared to solid configurations and consistently lower power peaking factors throughout burnup. The findings indicate that thorium-based fuels, particularly (Th-233U-235U)O2 in dual-cooled annular configuration, offer compelling advantages for SMR applications, including extended fuel cycles, improved safety characteristics, enhanced proliferation resistance, and superior thermal performance, supporting their viability as sustainable alternatives to conventional uranium-based fuels.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2025Enhanced thermal performance of a flat-plate solar water heating system using nanofluids: a TRNSYS-based analysis
Uzun, Sinem; Seyhan, Aslıhan Kurnuç
This study examines the potential of nanofluids to enhance the thermal efficiency of flat-plate solar water heating systems (SDHW) through numerical modeling using TRNSYS software. Improving the efficiency of such systems is critical for increasing the viability and sustainability of solar thermal technologies, particularly in regions with high solar potential like Türkiye. Three different nanofluids (Al2O3, TiO2, and CuO) were evaluated for their ability to improve heat transfer and system performance. Simulation results revealed that incorporating 0.1% Al2O3 into the working fluid increased the collector outlet temperature from 97 °C (with pure water) to 120 °C, indicating a 23% improvement. Comparable enhancements were observed with TiO2 and CuO nanofluids. Furthermore, collector efficiency, which typically ranges between 35 and 40% under peak solar conditions, was elevated to approximately 45% with the use of nanofluids. These findings suggest that nanofluids significantly improve thermal performance and energy conversion efficiency in SDHW systems. The results highlight the practical potential of nanofluids in advancing solar thermal technology and promoting cleaner, more efficient renewable energy solutions.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2024Determination of Radiation Value by Month Using Artificial Neural Network Model; Ankara, Sivas, Erzurum example
Uzun, Sinem; Arslantaş, Hatice
This research examines the estimation of solar radiation using artificial neural network (ANN) models in Turkish cities with similar latitude values such as Ankara, Sivas and Erzurum. The aim of this study is to investigate whether cities at similar latitudes exhibit similar trends in solar radiation values, despite their geographical differences. In this study, solar radiation prediction was made for 3 cities with a single-layer neural network. Monthly solar radiation intensity was estimated for the 10-year period between 2012 and 2022 with a total of 4764 samples taken from the General Directorate of State Meteorology. An artificial neural network model was developed with 8 units in the first hidden layer and 4 units in the second hidden layer. The optimizer used in compiling the model was determined as Adam, the loss function as 'mean_squared_error' and the metric as 'mse'. ReLU activation function was used in the input layer and hidden layers. A 10-year solar radiation intensity value was used in the output layer. 70% of the data set is reserved for training and 30% for testing data set. As a result, similar solar radiation trends were obtained in the same latitude regions, the results were confirmed by meteorological data.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2024The Effect of Nanofluid Coolant and Thorium-added Fuel on Burnup Dependent Isotopic Compositions in VVER-1000 Reactor
Acır, Adem; Genç, Yasin; Uzun, Sinem
Recently, the use of nanofluids has gained importance in studies aimed at increasing reactor efficiency while also addressing safety concerns in nuclear technology. Various studies have investigated the effects of adding nanoparticles of different types and proportions to the coolant water on the thermal and neutronic characteristics of power reactors using conventional UO2 fuels. Given the abundance of thorium compared to uranium, research on thorium-based fuels has become increasingly significant. In this study, the criticality and isotope changes in a VVER-1000 reactor loaded with 5% ThO2 and 95% UO2 by mass as fuel, and 0.1% by volume of Al2O3, CuO, and TiO2 nanoparticles as the coolant, were investigated. Neutronic analysis was performed using the MCNP5 and MONTEBURNS2.0 codes. The analysis results indicated that the operational lifespan of the reactor with only water coolant and thorium-based fuel was shortened due to the presence of nanoparticles. Furthermore, it was observed that while there was no significant change in the amount of fissile 235U and fertile 238U isotopes, the consumption of fertile 232Th isotope in the reactor increased with the insertion of nanoparticles into the coolant.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2024Exploring thermal flow dynamics in pressurized water reactors using hybrid graphene nanoplatelet coolants
Uzun, Sinem; Genç, Yasin; Acır, Adem
This study investigates the impact of hybrid nanoparticles on the temperature of nuclear reactor coolant, with a focus on graphene nanoplatelet (GNP)-based hybrid nanoparticles. Sixteen different hybrid nanofluids were analyzed, and their performance was compared with a standard water-based coolant. The criticality values were obtained through MCNP modeling, revealing that higher nanoparticle ratios led to increased criticality, with the highest value of 1.3239 observed in GNP-Fe3O4 + Al2O3 nanofluids (0.05 wt%) and the lowest value of 1.2935 in GNP–Fe3O4 + SiO2 nanofluids (0.001 wt%). Temperature variations showed that increasing nanoparticle concentrations resulted in slightly higher temperatures, with a maximum of 611.97 K for 0.05 vol.% GNP nanoparticles. Additionally, the departure from nucleate boiling ratio values were consistently above the safety threshold of 2.08, with the lowest value of 3.657 for GNP–Fe3O4 + SiO2 nanofluids (0.05 vol.%). These findings suggest that hybrid nanofluids, particularly those with higher nanoparticle ratios, can enhance the thermal performance and safety margins of nuclear reactor coolants, offering a promising avenue for future research and application.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2024Optimizing neural network models for predicting nuclear reactor channel temperature: A study on hyperparameter tuning and performance analysis
Uzun, Sinem; Yildiz, Eyyüp; Arslantaş, Hatice
This study emphasizes how important accurate prediction of channel temperatures in nuclear reactors is for safety and operational efficiency. While traditional methods require long and complex processes such as kernel modeling and mathematical simulations, artificial neural networks (ANN) provide more efficient predictions by accelerating this process. The superior ability of ANNs to process large data sets is intended to demonstrate that this study will provide a valuable alternative compared to conventional methods and increase the accuracy of reactor temperature predictions. In this study, the training performances of Artificial Neural Network (ANN) developed to determine the nuclear reactor channel temperature with different hyperparameter combinations were analysed. It was conducted several experimental studies to assess the influence of hyperparameters on our model for nuclear reactor parameter data prediction. The training and validation results indicates that learning rate, hidden layer sizes and number have critical effects for the more precisive prediction. It was observed that models with a learning rate of 0.05 and 0.5 achieved successful learning with less fluctuation in training and validation errors. When looking at hidden layer sizes, networks with 32 and 64 neurons performed better than networks with 16 neurons. For the test phase our model can successfully predict data with slight error margin. As a result, we demonstrated that neural networks are a powerful tool in nuclear reactor channel temperature prediction through our proposed model.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2023INVESTIGATION OF THE USE OF CALCIUM CARBONATE AS NANOPARTICLES IN NUCLEAR REACTORS
Uzun, Sinem; Genç, Yasin; Acir, Adem
In this study, calcium carbonate (CaCO3) 3 ) was considered as nanoparticle. In the first part of the study, half-value layer (HVL) and mean free path (MFP) values, which are radiation shielding parameters, were investigated in determined energy ranges by Phy-X open access software. At increasing energy levels, the HVL value reached approximately 10 cm, while the MFP value reached approximately 17 cm. In the second part of the study, the reactor core geometry was modeled with the MCNP code and then the relative power distribution values were determined. COBRA code input was prepared with the determined relative power distribution values and thermal analyzes were made. These analyzes were performed for three different nanoparticle ratios. As a result of the analysis, the temperature value at the end of the channel was 613 K when only water was used as a coolant, while the temperature value at the end of the channel was 611.19 K when 0.03% nanoparticles were used. Although the coolant temperature increased with the nanoparticle ratio, it was observed that the temperature decreased when only water was used.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2023Investigation of shielding properties of nuclear reactor control rod material boron carbide
Uzun, Sinem
In this study, potential usage of boron carbide (B4 C) in nuclear technology has been emphasized. B4 C is the base material for control rods used to control the fission rate in nuclear reactors. The high neutron absorption capacity of B4 C material makes it very useful for nuclear applications. In order to examine B4 C to be used in nuclear technology, the values of mass attenuation coefficient (MAC) and linear attenuation coefficient (LAC), half and tenth value layers (HVL, TVL) and mean free path (MFP) values were analyzed with open access Photon Protection and Dosimetry (PSD) software. The clad materials considered for the study are hafnium (Hf), indium (In), silver (Ag), cadmium (Cd) and B4 C. Analyzes were made in the energy range between 1 MeV and 15 MeV. In conclusion, when MeV was reached, the MAC value was found as 0.053 cm2/g for Hf and 0.015 cm2/g for B4 C. Moreover, while the HVL value was 1 cm for Hf, it was determined as 17 cm for B4 C at 15 MeV. The obtained results were compared with the literature and it was seen that they were compatible with the literature.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2022Evaluation of Irreversibility Analysis for Different Coal Types of a Thermal Power Plant
Uzun, Sinem
In this study, first law (energy conservation) and second law (exergy) analyzes of thermodynamics were performed for a thermal power plant. It is very important to perform energy and exergy analyzes in industrial plants. These analyzes can provide guidance on improving energy efficiency and recycling waste energy. In this study, energy and exergy analyzes were made for coals with different chemical contents in nine different countries. According to the results of the analysis, the highest first-law efficiency was found in Serbian coal (second type), as 53.61%. The second highest law efficiency was determined as 46.67% in Bangladesh coal (sixth type). Environmental Destruction Index (EDI) and Sustainability Index (SI) values were determined for all coal types. According to the results of the analysis, the highest EDI value was obtained as 4.00 at the temperature of 305 K for the 2nd coal type, and the highest SI value was obtained as 1.91 at the temperature of 293 K for the 6th coal type, according to the changing reference temperature values. According to this study, the highest second law efficiency was obtained from Bangladesh coal with a carbon (C) content of 77.84%.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2022Türkiye'de Ankara ili için düz plaka kollektör güneş sıcak su sisteminin TRNSYS yazılımı ile incelenmesi
Uzun, Sinem; Seyhan, Aslıhan Kurnuç; Coşkun, Salih
Düz plaka kollektör kullanan bir güneş enerjili su ısıtma sistemi, Türkiye'deki Ankara ili için, bir konut biriminin kullanım sıcak suyu ihtiyacı için modellenmiştir. Gerekli tasarım parametreleri belirlenmiş ve analizler TRNSYS simülasyon programı kullanılarak gerçekleştirilmiştir. Modellenen sistemde kullanım suyu sıcaklığı 55 °C olarak belirlenmiş ve kullanım yoğunluğuna göre gün içerisinde farklı debilerde su çekimleri gerçekleştirilmiştir. Su çekim hızları 07.00-09.00 saatleri arasında 80 kg/saat, 12.00-13.00 saatleri arasında 100 kg/saat ve 17.00-22.00 saatleri arasında 50 kg/saat olarak belirlenmiştir. Elde edilen sonuçlara göre tasarlanan sistem, yardımcı ısıtıcılar vasıtasıyla güneş enerjisi kullanılarak yaz ve kış aylarındaki sıcak su ihtiyacını karşılayabilmiştir. Kolektör verimi Eylül ayında %40 ile en yüksek değerine ulaşırken, Aralık ayında %8 ile en düşük verim değerine ulaşmıştır.
RDL Kalıcı Kaydıİncele - ArticleYayıncıda açık erişim2022Examination of flat plate collector solar hot water system for Ankara province in Turkiye with TRNSYS software
Seyhan, Aslihan Kurnuc; Uzun, Sinem; Coskun, Salih
A domestic solar water heating system using a flat plate collector is modeled for the domestic hot water requirement of a residential unit in Ankara, Turkey. The necessary design parameters were determined and the analysis was carried out using the TRNSYS simulation program. In the modeled system, the domestic water temperature was determined as 55 degrees C and water withdrawals were carried out at different flow rates during the day according to the usage intensity. The water withdrawal rates were determined as 80 kg/h between 07.00-09.00, 100 kg/h between 12.00-13.00 and 50 kg/h between 17.00-22.00. According to the results obtained, the designed system was able to meet the hot water need in summer and winter months by using solar energy through auxiliary heaters. While the collector efficiency reached its highest value with 40% in September, it reached the lowest efficiency value with 8% in December.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2022EXERGY ANALYSIS AND DETERMINATION OF IRREVERSIBILTY OF A THERMAL POWER PLANT
Ata, İsmail; Tanürün, H. Erdi; Uzun, Sinem; Bayrak, Sebile; Acır, Adem
The exergy analysis and determination of irreversibility İ of a thermal power plant with 210 MW are presented in this study. The first- (ηI) and second-law (ηII) efficiencies, losses, and İ are computed for each component in the plant. The highest energy loss (43.538%) occurs with heat transfer to cooling water of the condenser, whereas the second loss (14.138%) occurs in the boiler. The highest İ value in the cycle (86.87%) occurs in the boiler followed by the turbine (5.95%). The ηI and ηII efficiencies of the whole plant are 38.64% and 31.68%, respectively. In addition, effects of the efficiencies in the temperature range from 5°C to 30°C are investigated. The ηI efficiency of the whole plant does not change, whereas the ηII efficiency decreases with increasing reference temperatures. In addition, the ηII efficiency is associated with environmental impact and sustainability.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2022Investigation of hybrid nanofluids effects on heat transfer characteristics in VVER-1000 nuclear reactor
Uzun, Sinem; Genç, Yasin; Acır, Adem
In this study, the analysis of heat transfer characteristics of VVER-1000 nuclear reactor by using hybrid nanofluids as a coolants in subchannels in hot fuel assembly have been performed. Firstly, the criticality (keff) and fuel assembly power distributions of the VVER-1000 reactor by using Monte Carlo particle transport (MCNP) code to determine of the heat transfer characteristics with COBRA IV PC code have been examined. Secondly, the axial coolant temperature distributions and Departure from Nucleate Boiling Ratio (DNBR) values in hottest channel for Cu, CuO and TiO2 nanoparticles of the different volume fractions (0.05%, 0.01% and 0.1%) mixed with 0.1 vol % Al2O3 hybrid nanofluids have been analyzed. The obtained results by using hybrid nanofluids have been compared with the pure water results. The keff decreases with the increase of volumetric fractions of hybrid nanoparticles Cu, CuO and TiO2 mixed with 0.1% Al2O3 in the coolant. The maximum temperature has been reached by the püre water coolant at the end of the channel as 612.68 K whereas, the highest temperature change has been obtained in the case of 0.1% Al2O3 + 0.1% TiO2 as 617.35 K when evaluated among nanoparticle themselves. The results of analysis show that the heat transfer enhances with increasing hybrid nanoparticles volume fractions in the subchannel geometry. Also, the obtained minimum DNBR values using hybrid nanofluid haven't been exceed the safe operational limits; therefore the reactor operation would be safer.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2021Investigation of Neutronic and Thermal Performance Using UGD and MOX Fuel in VVER-1000 Nuclear Power Reactor
Uzun, Sinem; Genç, Yasin; Acir, Adem
When examining the safety and design features of nuclear power reactors, its thermal performance in addition to neutronic characteristics is important. In this study, the neutronic and thermal performances of VVER-1000 reactor with two different fuel assembly arrangements were examined. Those fuel assemblies named as YD1 and YD2 are composed of 3.7% enriched LEU and 3.6% enriched LEU with 4% Gd2O3 uranium-gadolinium (UGD) and 2%, 3%, 4.2% Pu and 3.6% enriched LEU with 4% Gd2O3 (MOXGD), respectively. The effects of using UGD and MOXGD fuel assembly arrangements on criticality and isotope transformations according to burnup rate were investigated by means of MCNP5 and MONTEBURNS2.0 nuclear code, correspondingly the temperature and enthalpy changes of the coolant along the hot channel were examined with the help of the COBRA-IV PC thermal analysis code. The results obtained from this study were compared with similar studies in the literature and it was observed that the obtained findings were in accordance with the literature.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2021Investigation of thermal performance of aluminum nanoparticle coolant in vver-1000 reactor
Uzun, Sinem; Genç, Yasin; Acir, Adem
Thermal analysis is of great importance when examining the safety and design features of nuclear power reactors. The aim of this study is to examine the effect of pure water and coolant containing Al2O3 nanoparticles on thermal performance of VVER-1000 nuclear reactor. In this study, the VVER-1000 reactor is in steady state and BOC (begining of cycle) condition, relative power density distributions for UO2 fuel with 3.7% enrichment were obtained with the MCNP code and then, thermal analysis were made with the COBRA code and DNBR value, which is very important for the safety criteria of the reactor, was examined. In addition, with the COBRA code, thermal values such as temperature, enthalpy, density, and temperature values of the fuel and clad regions, which are of great importance for the reactor, were calculated. As a result of the analysis, it was determined that the most efficient coolant is 0.1% Al2O3 fluid in the heat transfer of the reactor.
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