The Experts below are selected from a list of 201 Experts worldwide ranked by ideXlab platform
Hiroshi Sekimoto - One of the best experts on this subject based on the ideXlab platform.
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Void reactivity aspect and fuel conversion potential of heavy water cooled Thorium Reactor
International Journal of Energy Research, 2016Co-Authors: Sidik Permana, Abdul Waris, Zaki Su’ud, Hiroshi SekimotoAbstract:Summary Design study on heavy water cooled Thorium breeding Reactor has been investigated by adopting a nuclear equilibrium state model. Conversion ratio, as an important index, has been evaluated to estimate the breeding capability of the Reactors. Void reactivity coefficient has also been investigated to evaluate performance index of safety aspect, which is based on the criticality performance of the Reactors during voided condition. In addition, moderator-to-fuel ratio has also been employed to analyze its effect to the required enrichment, conversion ratio, and void reactivity coefficient as well as different burnups and fuel pin diameter effects. Void reactivity coefficient indicates a criticality condition of the Reactor when some coolants are lost. If the negative value of void reactivity is achieved, it means that the Reactor has less reactivity condition as well as less power production when lost of coolant occurred. Higher fuel conversion capability, that more nuclear fuel are produced, those additional fuel productions can be used for next operation or for other Reactors. The results show that higher fuel conversion ratio can be achieved for less moderator-to-fuel ratio because of the harder neutron spectrum effect, while it requires more fissile content of 233U to maintain the Reactor operation from fission reaction. Higher burnup gives less conversion ratio because some fissile materials are used to maintain longer Reactor operation, and at the same time, it requires more initial required fissile 233U for higher burnup. In addition, it requires less fissile 233U for thicker fuel pin diameter, while its conversion ratio becomes higher, and void reactivity coefficient is more negative for thicker fuel pin diameter. The results also show that Thorium utilization on heavy water cooled Reactor gives all negative void reactivity values, which means that the system has a safety condition in terms of void reactivity condition. At the same time, it shows some feasible conditions for obtaining fuel breeding to increase the sustainability of nuclear fuel. Copyright © 2016 John Wiley & Sons, Ltd.
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Breeding and void reactivity analysis on heavy metal closed-cycle water cooled Thorium Reactor
Annals of Nuclear Energy, 2010Co-Authors: Sidik Permana, Naoyuki Takaki, Hiroshi SekimotoAbstract:Abstract Design parameters of heavy water (D 2 O) cooled Thorium breeder Reactors for actinides closed-cycle cases have been investigated to find a design feasible area of breeding and negative void reactivity. Heavy metals (HMs) closed-cycle shows narrower feasible area compared with feasible area of 233 U closed-cycle. In Thorium fuel cycle, the breeding capability of the Reactors becomes worse when all HMs are recycled. The result shows an opposite profile of breeding capability compared with uranium fuel cycle which obtains higher breeding capability when more HMs are recycled. Feasible design area which has a breeding and negative void reactivity can be estimated for higher burnup, even higher than 60 GW d/t for 233 U closed-cycle; however, it is limited to 36 GW d/t for HM closed-cycle. Contribution of capture 235 U is more significant to reduce breeding capability and contribution of 234 U is also more effective to make the Reactor more positive or less negative void coefficient for HM closed-cycle case in Thorium fuel cycle system.
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Fuel Breeding and Core Behavior Analyses on In Core Fuel Management of Water Cooled Thorium Reactors
2010Co-Authors: Sidik Permana, Hiroshi Sekimoto, Abdul Waris, Muhamad Nurul Subhki, IsmailAbstract:Thorium fuel cycle with recycled U‐233 has been widely recognized having some contributions to improve the water‐cooled breeder Reactor program which has been shown by a feasible area of breeding and negative void reactivity which confirms that fissile of 233U contributes to better fuel breeding and effective for obtaining negative void reactivity coefficient as the main fissile material. The present study has the objective to estimate the effect of whole core configuration as well as burnup effects to the Reactor core profile by adopting two dimensional model of fuel core management. About more than 40 months of cycle period has been employed for one cycle fuel irradiation of three batches fuel system for large water cooled Thorium Reactors. All position of fuel arrangement contributes to the total core conversion ratio which gives conversion ratio less than unity of at the BOC and it contributes to higher than unity (1.01) at the EOC after some irradiation process. Inner part and central part give the important part of breeding contribution with increasing burnup process, while criticality is reduced with increasing the irradiation time. Feasibility of breeding capability of water‐cooled Thorium Reactors for whole core fuel arrangement has confirmed from the obtained conversion ratio which shows higher than unity. Whole core analysis on evaluating reactivity change which is caused by the change of voided condition has been employed for conservative assumption that 100% coolant and moderator are voided. It obtained always a negative void reactivity coefficient during Reactor operation which shows relatively more negative void coefficient at BOC (fresh fuel composition), and it becomes less negative void coefficient with increasing the operation time. Negative value of void reactivity coefficient shows the Reactor has good safety properties in relation to the reactivity profile which is the main parameter in term of criticality safety analysis. Therefore, this evaluation has confirmed that breeding condition and negative coefficient can be obtained simultaneously for water‐cooled Thorium Reactor obtains based on the whole core fuel arrangement.
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breeding capability and void reactivity analysis of heavy water cooled Thorium Reactor
Journal of Nuclear Science and Technology, 2008Co-Authors: Sidik Permana, Naoyuki Takaki, Hiroshi SekimotoAbstract:The fuel breeding and void reactivity coefficient of Thorium Reactors have been investigated using heavy water as coolant for several parametric surveys on moderator-to-fuel ratio (MFR) and burnup. The equilibrium fuel cycle burnup calculation has been performed, which is coupled with the cell calcu- lation for this evaluation. Theof 233 U shows its superiority over other fissile nuclides in the surveyed MFR ranges and always stays higher than 2.1, which indicates that the Reactor has a breeding condition for a wide range of MFR. A breeding condition with a burnup comparable to that of a standard PWR or higher can be achieved by adopting a larger pin gap (1-6 mm), and a pin gap of about 2 mm can be used to achieve a breeding ratio (BR) of 1.1. A feasible design region of the Reactors, which fulfills the breeding condition and negative void reactivity coefficient, has been found. A heavy-water-cooled PWR-type Th- 233 U fuel Reactor can be designed as a breeder Reactor with negative void coefficient.
Sidik Permana - One of the best experts on this subject based on the ideXlab platform.
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Basic design parameter optimization on water cooled Thorium breeder Reactor
Annals of Nuclear Energy, 2020Co-Authors: Sidik PermanaAbstract:Abstract Basic study on optimization of heavy water cooled Thorium breeding Reactor has been investigated to estimate the feasible design region of breeding and negative void reactivity coefficient. Those parametric surveys are moderator to fuel ratio, fuel pin diameter, fuel pellet power density, and void faction. A fuel pin diameter of 14.5 mm shows the optimum feasible fuel breeding and less required U-233 fissile content. The systems require the enrichment less than 8% and it gives some possible area of breeding. The effect of moderator is essential to make the negative void reactivity. Void fraction effect is still good enough to make more negative void reactivity, however, for no more heavy water as moderator, it obtains less negative void reactivity or becomes slightly positive. It has been shown that several significant parameters affect to the feasibility breeding windows and potential negative void reactivity based on heavy water-cooled Thorium Reactor.
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Fuel Breeding Analysis On Low Moderated Fuel Ratio Based On Actinides Closed Water-Cooled Thorium Reactor
Journal of Physics: Conference Series, 2018Co-Authors: Sidik Permana, Syeilendra Pramuditya, Dwi IrwantoAbstract:Utilization of spent nuclear fuel and some fuel breeding capabilities of nuclear fuels to extend the sustainability aspect of nuclear fuel become more important issues to be optimized. Thorium fuel utilization based on water-cooled Reactor is one of the possible options to be used and optimized as well as uranium fuel utilization. Some schemes of accumulated spent nuclear fuels can be used as recycled fuel in water-cooled Reactor based on Thorium fuel. In the present analysis, fuel sustainability aspect of nuclear fuel will be evaluated, which is based on a water-cooled Reactor. As a fuel basis, Thorium is used with can be mixed with additional recycled spent nuclear fuels. Some minor actinides (MA) as recycled fuels are used as doping material to be loaded to the water cooled Reactors with Thorium fuel as fuel basis and heavy water as moderator and coolant. The evaluation has been made by adopting a computational simulation of an equilibrium burnup analysis method, which was coupled with cell calculation of computer code of SRAC with JENDL.32 as nuclear data library. Several survey parameters have been evaluated to evaluate some effect of MA doping rate, different moderation ratio and power density levels to the Reactor performance including fuel-breeding capability and void reactivity coefficient. Effect of some actinide composition to fuel breeding capability as well as safety aspect, which is based on void reactivity coefficient have been investigated. Fuel breeding capability can be obtained by the present Reactor systems; as well as negative void reactivity has been show for more moderator ratio and less power density. Low portion of moderation to fuel ratios (MFR) are used to have a better fuel breeding capability as well as some from contribution from recycled fuel of minor actinides (MA) and less power density. A negative void reactivity can be obtained in this system and it becomes less negative for doping MA and more power density as well as a positive void reactivity coefficient value for much less moderation ratio.
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fuel breeding analysis on low moderated fuel ratio based on actinides closed water cooled Thorium Reactor
Journal of Physics: Conference Series, 2018Co-Authors: Sidik Permana, Syeilendra Pramuditya, Dwi IrwantoAbstract:Utilization of spent nuclear fuel and some fuel breeding capabilities of nuclear fuels to extend the sustainability aspect of nuclear fuel become more important issues to be optimized. Thorium fuel utilization based on water-cooled Reactor is one of the possible options to be used and optimized as well as uranium fuel utilization. Some schemes of accumulated spent nuclear fuels can be used as recycled fuel in water-cooled Reactor based on Thorium fuel. In the present analysis, fuel sustainability aspect of nuclear fuel will be evaluated, which is based on a water-cooled Reactor. As a fuel basis, Thorium is used with can be mixed with additional recycled spent nuclear fuels. Some minor actinides (MA) as recycled fuels are used as doping material to be loaded to the water cooled Reactors with Thorium fuel as fuel basis and heavy water as moderator and coolant. The evaluation has been made by adopting a computational simulation of an equilibrium burnup analysis method, which was coupled with cell calculation of computer code of SRAC with JENDL.32 as nuclear data library. Several survey parameters have been evaluated to evaluate some effect of MA doping rate, different moderation ratio and power density levels to the Reactor performance including fuel-breeding capability and void reactivity coefficient. Effect of some actinide composition to fuel breeding capability as well as safety aspect, which is based on void reactivity coefficient have been investigated. Fuel breeding capability can be obtained by the present Reactor systems; as well as negative void reactivity has been show for more moderator ratio and less power density. Low portion of moderation to fuel ratios (MFR) are used to have a better fuel breeding capability as well as some from contribution from recycled fuel of minor actinides (MA) and less power density. A negative void reactivity can be obtained in this system and it becomes less negative for doping MA and more power density as well as a positive void reactivity coefficient value for much less moderation ratio.
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Void reactivity aspect and fuel conversion potential of heavy water cooled Thorium Reactor
International Journal of Energy Research, 2016Co-Authors: Sidik Permana, Abdul Waris, Zaki Su’ud, Hiroshi SekimotoAbstract:Summary Design study on heavy water cooled Thorium breeding Reactor has been investigated by adopting a nuclear equilibrium state model. Conversion ratio, as an important index, has been evaluated to estimate the breeding capability of the Reactors. Void reactivity coefficient has also been investigated to evaluate performance index of safety aspect, which is based on the criticality performance of the Reactors during voided condition. In addition, moderator-to-fuel ratio has also been employed to analyze its effect to the required enrichment, conversion ratio, and void reactivity coefficient as well as different burnups and fuel pin diameter effects. Void reactivity coefficient indicates a criticality condition of the Reactor when some coolants are lost. If the negative value of void reactivity is achieved, it means that the Reactor has less reactivity condition as well as less power production when lost of coolant occurred. Higher fuel conversion capability, that more nuclear fuel are produced, those additional fuel productions can be used for next operation or for other Reactors. The results show that higher fuel conversion ratio can be achieved for less moderator-to-fuel ratio because of the harder neutron spectrum effect, while it requires more fissile content of 233U to maintain the Reactor operation from fission reaction. Higher burnup gives less conversion ratio because some fissile materials are used to maintain longer Reactor operation, and at the same time, it requires more initial required fissile 233U for higher burnup. In addition, it requires less fissile 233U for thicker fuel pin diameter, while its conversion ratio becomes higher, and void reactivity coefficient is more negative for thicker fuel pin diameter. The results also show that Thorium utilization on heavy water cooled Reactor gives all negative void reactivity values, which means that the system has a safety condition in terms of void reactivity condition. At the same time, it shows some feasible conditions for obtaining fuel breeding to increase the sustainability of nuclear fuel. Copyright © 2016 John Wiley & Sons, Ltd.
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Breeding and void reactivity analysis on heavy metal closed-cycle water cooled Thorium Reactor
Annals of Nuclear Energy, 2010Co-Authors: Sidik Permana, Naoyuki Takaki, Hiroshi SekimotoAbstract:Abstract Design parameters of heavy water (D 2 O) cooled Thorium breeder Reactors for actinides closed-cycle cases have been investigated to find a design feasible area of breeding and negative void reactivity. Heavy metals (HMs) closed-cycle shows narrower feasible area compared with feasible area of 233 U closed-cycle. In Thorium fuel cycle, the breeding capability of the Reactors becomes worse when all HMs are recycled. The result shows an opposite profile of breeding capability compared with uranium fuel cycle which obtains higher breeding capability when more HMs are recycled. Feasible design area which has a breeding and negative void reactivity can be estimated for higher burnup, even higher than 60 GW d/t for 233 U closed-cycle; however, it is limited to 36 GW d/t for HM closed-cycle. Contribution of capture 235 U is more significant to reduce breeding capability and contribution of 234 U is also more effective to make the Reactor more positive or less negative void coefficient for HM closed-cycle case in Thorium fuel cycle system.
Naoyuki Takaki - One of the best experts on this subject based on the ideXlab platform.
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Core Design and Deployment Strategy of Heavy Water Cooled Sustainable Thorium Reactor
Sustainability, 2012Co-Authors: Naoyuki Takaki, Deby MardiansahAbstract:Abstract: Our previous studies on water cooled Thorium breeder Reactor based on matured pressurized water Reactor (PWR) plant technology concluded that reduced moderated core by arranging fuel pins in a triangular tight lattice array and using heavy water as coolant is appropriate for achieving better breeding performance and higher burn-up simultaneously [1–6]. One optimum core that produces 3.5 GW thermal energy using Th- 233 U oxide fuel shows a breeding ratio of 1.07 and averaged burn-up of about 80 GWd/t with long cycle length of 1300 days. The moderator to fuel volume ratio is 0.6 and required enrichment of 233 U for the fresh fuel is about 7%. The coolant reactivity coefficient is negative during all cycles despite it being a large scale breeder Reactor. In order to introduce this sustainable Thorium Reactor, three-step deployment scenario, with intermediate transition phase between current light water Reactor (LWR) phase and future sustainer phase, is proposed. Both in transition phase and sustainer phase, almost the same core design can be applicable only by changing fissile materials mixed with Thorium from plutonium to
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Breeding and void reactivity analysis on heavy metal closed-cycle water cooled Thorium Reactor
Annals of Nuclear Energy, 2010Co-Authors: Sidik Permana, Naoyuki Takaki, Hiroshi SekimotoAbstract:Abstract Design parameters of heavy water (D 2 O) cooled Thorium breeder Reactors for actinides closed-cycle cases have been investigated to find a design feasible area of breeding and negative void reactivity. Heavy metals (HMs) closed-cycle shows narrower feasible area compared with feasible area of 233 U closed-cycle. In Thorium fuel cycle, the breeding capability of the Reactors becomes worse when all HMs are recycled. The result shows an opposite profile of breeding capability compared with uranium fuel cycle which obtains higher breeding capability when more HMs are recycled. Feasible design area which has a breeding and negative void reactivity can be estimated for higher burnup, even higher than 60 GW d/t for 233 U closed-cycle; however, it is limited to 36 GW d/t for HM closed-cycle. Contribution of capture 235 U is more significant to reduce breeding capability and contribution of 234 U is also more effective to make the Reactor more positive or less negative void coefficient for HM closed-cycle case in Thorium fuel cycle system.
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breeding capability and void reactivity analysis of heavy water cooled Thorium Reactor
Journal of Nuclear Science and Technology, 2008Co-Authors: Sidik Permana, Naoyuki Takaki, Hiroshi SekimotoAbstract:The fuel breeding and void reactivity coefficient of Thorium Reactors have been investigated using heavy water as coolant for several parametric surveys on moderator-to-fuel ratio (MFR) and burnup. The equilibrium fuel cycle burnup calculation has been performed, which is coupled with the cell calcu- lation for this evaluation. Theof 233 U shows its superiority over other fissile nuclides in the surveyed MFR ranges and always stays higher than 2.1, which indicates that the Reactor has a breeding condition for a wide range of MFR. A breeding condition with a burnup comparable to that of a standard PWR or higher can be achieved by adopting a larger pin gap (1-6 mm), and a pin gap of about 2 mm can be used to achieve a breeding ratio (BR) of 1.1. A feasible design region of the Reactors, which fulfills the breeding condition and negative void reactivity coefficient, has been found. A heavy-water-cooled PWR-type Th- 233 U fuel Reactor can be designed as a breeder Reactor with negative void coefficient.
Igor Shamanin - One of the best experts on this subject based on the ideXlab platform.
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Maintaining the close-to-critical state of Thorium fuel core of hybrid Reactor operated under control by D-T fusion neutron flux
Nuclear Engineering and Technology, 2020Co-Authors: Sergey Bedenko, Alexander Karengin, Andrey V. Arzhannikov, Igor O. Lutsik, V. V. Prikhodko, Vladimir M. Shmakov, Dmitry G. Modestov, Igor ShamaninAbstract:Abstract The results of full-scale numerical experiments of a hybrid Thorium-containing fuel cell facility operating in a close-to-critical state due to a controlled source of fusion neutrons are discussed in this work. The facility under study was a complex consisting of two blocks. The first block was based on the concept of a high-temperature gas-cooled Thorium Reactor core. The second block was an axially symmetrical extended plasma generator of additional neutrons that was placed in the near-axial zone of the facility blanket. The calculated models of the blanket and the plasma generator of D-T neutrons created within the work allowed for research of the neutronic parameters of the facility in stationary and pulse-periodic operation modes. This research will make it possible to construct a safe facility and investigate the properties of Thorium fuel, which can be continuously used in the epithermal spectrum of the considered hybrid fusion–fission Reactor.
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Facility to study neutronic properties of a hybrid Thorium Reactor with a source of thermonuclear neutrons based on a magnetic trap
Nuclear Engineering and Technology, 2020Co-Authors: Andrey V. Arzhannikov, Sergey Bedenko, Igor O. Lutsik, Vladimir M. Shmakov, Dmitry G. Modestov, V. V. Prikhodko, Igor ShamaninAbstract:Abstract To study the thermophysical and neutronic properties of Thorium-plutonium fuel, a conceptual design of a hybrid facility consisting of a subcritical Th–Pu Reactor core and a source of additional D-D neutrons that places on the axis of the core is proposed. The source of such neutrons is a column of high-temperature plasma held in a long magnetic trap for D-D fusionreactions. This article presents computer simulation results of generation of thermonuclear neutrons in the plasma, facility neutronic properties and the evolution of a fuel nuclide composition in the Reactor core. Simulations were performed for an axis-symmetric radially profiled Reactor core consisting of zones with various nuclear fuel composition. Such Reactor core containing a continuously operating stationary D-D neutron source with a yield intensity of Y = 2 × 1016 neutrons per second can operate as a nuclear hybrid system at its effective coefficient of neutron multiplication 0.95–0.99. Options are proposed for optimizing plasma parameters to increase the neutron yield in order to compensate the effective multiplication factor decreasing and plant power in a long operating cycle (3000-day duration). The obtained simulation results demonstrate the possibility of organizing the stable operation of the proposed hybrid ‘fusion–fission’ facility.
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Gas-cooled Thorium Reactor at various fuel loadings and its modification by a plasma source of extra neutrons
Nuclear Science and Techniques, 2019Co-Authors: Andrey Arzhannikov, Sergey Bedenko, Vladimir Shmakov, Vladimir Knyshev, Igor Lutsik, Vadim Prikhodko, Igor ShamaninAbstract:This work presents the results of computer simulation of neutronic processes in a high-temperature gas-cooled Thorium Reactor for 30 different options of core loading. To guarantee stable and long-term Reactor operation (7–10 years), the quantity of fuel compact dispersion phase and starting fuel composition was selected. It is demonstrated that it is possible in principle to substitute the near-axial recirculation zone of the Reactor core by a long magnetic trap with a high-temperature plasma column for generating thermonuclear neutrons. The distribution of neutron yield along the length of the plasma source is also presented. Such a Thorium Reactor, with a near-axial source of extra neutrons, can be applied for researching thermophysical and neutronic characteristics of dispersion Thorium fuel to improve its properties. The results of the work are of great interest from the perspective of future advancement of the thermonuclear power industry, by means of creation of a hybrid installation based on a Thorium Reactor with a long plasma column as a source of additional neutrons.
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Peculiarities of the radiation formation in dispersed microencapsulated nuclear fuel
Nuclear Energy and Technology, 2019Co-Authors: Sergey Bedenko, V V Knyshev, Igor O. Lutsik, Mariya Ye. Kuznetsova, Igor ShamaninAbstract:A computational study has been performed for various options of the Thorium Reactor core loading. Neutronic studies of fuel have been conducted, its isotopic composition has been calculated, and the alpha emitters and the sources of neutron and photon radiation in the microencapsulated nuclear fuel have been analyzed. The studies had the purpose of developing the methodology used to estimate the radiation characteristics of nuclear fuel with a complex inner structure. Emphasis is placed on calculating the quantitative and spectral composition of the neutrons formed as the result of (a, n) reactions on small- and average-mass nuclei. The ratio of the quantity of the neutrons resulting from the (a, n) reactions to the quantity of the neutrons formed as the result of spontaneous fission has been calculated for fuel with heterogeneous and homogeneous arrangements of fissionable and structural elements. The developed tools will make it possible to estimate the neutron radiation dose, to revise the traditional fresh and spent fuel handling procedures, and to estimate, using the Rossi alpha method, the neutron multiplication factor in deeply subcritical systems. The neutron yield and spectrum were calculated using an analytical model and verified codes such as WIMS-D5B, ORIGEN-APP, SOURCES-4C and SRIM-2013.
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Thermo-physical properties of dispersion nuclear fuel for a new-generation Reactors: A computational approach
2019Co-Authors: Sergey Bedenko, V V Knyshev, Alexander Karengin, Nima Ghal-eh, Nikita Alekseev, Igor ShamaninAbstract:Tomsk Polytechnic University is conducting a series of experiments to develop a nuclear fuel manufacturing technology required for a new-generation innovative nuclear systems. In this study, the thermal conductivity and thermophysical properties were calculated for the proposed nuclear fuel, which are necessary before proceeding to the construction stage. The cylindrical fuel compact consisting of spherical coated constituents (Pu,Th)O2 of BISO type, were sintered together within a graphite matrix (C). Also, a composite material made of nuclear fuel (Pu,Th)O2 and refractory oxides BeO/MgO, were prepared using plasma-chemical synthesis method. The development of a fuel pellet with desired physical properties that can be exposed for a long time under irradiation in a high-temperature gas-cooled Thorium Reactor core is the main technological advantage of the present study.
Abdul Waris - One of the best experts on this subject based on the ideXlab platform.
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Void reactivity aspect and fuel conversion potential of heavy water cooled Thorium Reactor
International Journal of Energy Research, 2016Co-Authors: Sidik Permana, Abdul Waris, Zaki Su’ud, Hiroshi SekimotoAbstract:Summary Design study on heavy water cooled Thorium breeding Reactor has been investigated by adopting a nuclear equilibrium state model. Conversion ratio, as an important index, has been evaluated to estimate the breeding capability of the Reactors. Void reactivity coefficient has also been investigated to evaluate performance index of safety aspect, which is based on the criticality performance of the Reactors during voided condition. In addition, moderator-to-fuel ratio has also been employed to analyze its effect to the required enrichment, conversion ratio, and void reactivity coefficient as well as different burnups and fuel pin diameter effects. Void reactivity coefficient indicates a criticality condition of the Reactor when some coolants are lost. If the negative value of void reactivity is achieved, it means that the Reactor has less reactivity condition as well as less power production when lost of coolant occurred. Higher fuel conversion capability, that more nuclear fuel are produced, those additional fuel productions can be used for next operation or for other Reactors. The results show that higher fuel conversion ratio can be achieved for less moderator-to-fuel ratio because of the harder neutron spectrum effect, while it requires more fissile content of 233U to maintain the Reactor operation from fission reaction. Higher burnup gives less conversion ratio because some fissile materials are used to maintain longer Reactor operation, and at the same time, it requires more initial required fissile 233U for higher burnup. In addition, it requires less fissile 233U for thicker fuel pin diameter, while its conversion ratio becomes higher, and void reactivity coefficient is more negative for thicker fuel pin diameter. The results also show that Thorium utilization on heavy water cooled Reactor gives all negative void reactivity values, which means that the system has a safety condition in terms of void reactivity condition. At the same time, it shows some feasible conditions for obtaining fuel breeding to increase the sustainability of nuclear fuel. Copyright © 2016 John Wiley & Sons, Ltd.
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Fuel Breeding and Core Behavior Analyses on In Core Fuel Management of Water Cooled Thorium Reactors
2010Co-Authors: Sidik Permana, Hiroshi Sekimoto, Abdul Waris, Muhamad Nurul Subhki, IsmailAbstract:Thorium fuel cycle with recycled U‐233 has been widely recognized having some contributions to improve the water‐cooled breeder Reactor program which has been shown by a feasible area of breeding and negative void reactivity which confirms that fissile of 233U contributes to better fuel breeding and effective for obtaining negative void reactivity coefficient as the main fissile material. The present study has the objective to estimate the effect of whole core configuration as well as burnup effects to the Reactor core profile by adopting two dimensional model of fuel core management. About more than 40 months of cycle period has been employed for one cycle fuel irradiation of three batches fuel system for large water cooled Thorium Reactors. All position of fuel arrangement contributes to the total core conversion ratio which gives conversion ratio less than unity of at the BOC and it contributes to higher than unity (1.01) at the EOC after some irradiation process. Inner part and central part give the important part of breeding contribution with increasing burnup process, while criticality is reduced with increasing the irradiation time. Feasibility of breeding capability of water‐cooled Thorium Reactors for whole core fuel arrangement has confirmed from the obtained conversion ratio which shows higher than unity. Whole core analysis on evaluating reactivity change which is caused by the change of voided condition has been employed for conservative assumption that 100% coolant and moderator are voided. It obtained always a negative void reactivity coefficient during Reactor operation which shows relatively more negative void coefficient at BOC (fresh fuel composition), and it becomes less negative void coefficient with increasing the operation time. Negative value of void reactivity coefficient shows the Reactor has good safety properties in relation to the reactivity profile which is the main parameter in term of criticality safety analysis. Therefore, this evaluation has confirmed that breeding condition and negative coefficient can be obtained simultaneously for water‐cooled Thorium Reactor obtains based on the whole core fuel arrangement.