scholarly journals Optimization of the self-sufficient thorium fuel cycle for CANDU power reactors

2008 ◽  
Vol 23 (1) ◽  
pp. 3-10
Author(s):  
Boris Bergelson ◽  
Alexander Gerasimov ◽  
Georgy Tikhomirov
Keyword(s):  
New Technologies ◽  
Fuel Cycle ◽  
Fission Products ◽  
The Self ◽  
Fissile Material ◽  
Heavy Nuclei ◽  
Candu Reactors ◽  
Mode Of Operation ◽  
Enriched Uranium ◽  
Thorium Cycle

The results of optimization calculations for CANDU reactors operating in the thorium cycle are presented in this paper. Calculations were performed to validate the feasibility of operating a heavy-water thermal neutron power reactor in a self-sufficient thorium cycle. Two modes of operation were considered in the paper: the mode of preliminary accumulation of 233U in the reactor itself and the mode of operation in a self-sufficient cycle. For the mode of accumulation of 233U, it was assumed that enriched uranium or plutonium was used as additional fissile material to provide neutrons for 233U production. In the self-sufficient mode of operation, the mass and isotopic composition of heavy nuclei unloaded from the reactor should provide (after the removal of fission products) the value of the multiplication factor of the cell in the following cycle K>1. Additionally, the task was to determine the geometry and composition of the cell for an acceptable burn up of 233U. The results obtained demonstrate that the realization of a self-sufficient thorium mode for a CANDU reactor is possible without using new technologies. The main features of the reactor ensuring a self-sufficient mode of operation are a good neutron balance and moving of fuel through the active core.

scholarly journals The mode of operation of CANDU power reactor in thorium self-sufficient fuel cycle

2008 ◽  
Vol 23 (2) ◽  
pp. 16-21
Author(s):  
Boris Bergelson ◽  
Alexander Gerasimov ◽  
Georgy Tikhomirov
Keyword(s):  
Fuel Cycle ◽  
Power Reactor ◽  
The Self ◽  
Fissile Material ◽  
Reactor Operation ◽  
Active Core ◽  
Mode Of Operation ◽  
Neutron Power ◽  
Thorium Cycle ◽  
Maximum Content

This paper presents the results of calculations for CANDU reactor operation in the thorium fuel cycle. The calculations were performed to estimate feasibility of operation of a heavy-water thermal neutron power reactor in the self-sufficient thorium cycle. The parameters of the active core and the scheme of fuel reloading were considered to be the same as for the standard operation in the uranium cycle. Two modes of operation are discussed in the paper: the mode of preliminary accumulation of 233U and the mode of operation in the self-sufficient cycle. For calculations for the mode of accumulation of 233U, it was assumed that plutonium was used as the additional fissile material to provide neutrons for 233U production. Plutonium was placed in fuel channels, while 232Th was located in target channels. The maximum content of 233U in the target channels was about 13 kg/t of ThO2. This was achieved by six year irradiation. The start of reactor operation in the self-sufficient mode requires content of 233U not less than 12 kg/t. For the mode of operation in the self-sufficient cycle, it was assumed that all the channels were loaded with the identical fuel assemblies containing ThO2 and a certain amount of 233U. It was shown that the non-uniform distribution of 233U in a fuel assembly is preferable.

Achieving Resource Sustainability in China Through the Thorium Fuel Cycle in the Candu Reactor

2010 ◽  
Author(s):  
Peter G. Boczar ◽  
Bronwyn Hyland ◽  
Keith Bradley ◽  
Sermet Kuran
Keyword(s):  
Fuel Cycle ◽  
Close Approach ◽  
Natural Uranium ◽  
Fissile Material ◽  
Energy Potential ◽  
Candu Reactors ◽  
Fuel Cycles ◽  
Resource Sustainability ◽  
Enriched Uranium

The CANDU® reactor is the most resource-efficient reactor commercially available. The features that enable the CANDU reactor to utilize natural uranium facilitate the use of a wide variety of thorium fuel cycles. In the short term, the initial fissile material would be provided in a “mixed bundle”, in which low-enriched uranium (LEU) would comprise the outer two rings of a CANFLEX® bundle, with ThO2 in the central 8 elements. This cycle is economical, both in terms of fuel utilization and fuel cycle costs. The medium term strategy would be defined by the availability of plutonium and recovered uranium from reprocessed used LWR fuel. The plutonium could be used in Pu/Th bundles in the CANDU reactor, further increasing the energy derived from the thorium. Recovered uranium could also be effectively utilized in CANDU reactors. In the long term, the full energy potential from thorium could be realized through the recycle of the U-233 (and thorium) in the used CANDU fuel. Plutonium would only be required to top up the fissile content to achieve the desired burnup. Further improvements to the CANDU neutron economy could make possible a very close approach to the Self-Sufficient Equilibrium Thorium (SSET) cycle with a conversion ratio of unity, which would be completely self-sufficient in fissile material (recycled U-233).

Thorium Cycle in High Temperature Gas-Cooled Gas Turbine Reactors (HTG-GT) Using Highly Enriched Uranium Obtained From the Dismantling of Nuclear Weapons

1994 ◽  
Author(s):  
Nicola Cerullo ◽  
Giovanni Guglielmini ◽  
A. Di Pietro
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Nuclear Weapons ◽  
Fuel Cycle ◽  
Fissile Material ◽  
High Investment ◽  
Enriched Uranium ◽  
The Cold War ◽  
Thorium Cycle ◽  
High Temperature Gas

The closed thorium fuel cycle is based on the use of fissile U-233 produced by the thorium fertilization in the original fuel element without any refabrication action, which is very difficult, due to the high activity of Thorium activated products. The need of a consistent amount of fissile material for beginning the U-Th cycle activity, in order to sustain the Thorium conversion reactions, requires an high initial U-235 enrichment. This condition, due to high investment costs, stopped, in the last years, any initiative in this field. The end of the cold war and the disarmament agreements pose the problem of the use of military grade fissile materials resulting from the dismantling of nuclear weapons both Russian and American. In this paper the problem is analyzed and a High Temperature Gas-cooled Gas Turbine (HTG-GT) reactor, using a nuclear U-Th fuel cycle utilizing military grade highly enriched uranium, is proposed.

Variants of the Perspective Closed Fuel Cycle, Based on REMIX-Technology

2014 ◽  
Author(s):  
Evgeniy Bobrov ◽  
Pavel Teplov ◽  
Pavel Alekseev ◽  
Alexander Chibinyaev ◽  
Anatoliy Dudnikox
Keyword(s):  
Fuel Cycle ◽  
Raw Materials ◽  
Natural Uranium ◽  
Depleted Uranium ◽  
Raw Material ◽  
Fissile Material ◽  
Spent Fuel ◽  
Closed Fuel Cycle ◽  
New Variant ◽  
Enriched Uranium

In the traditional closed fuel cycle, based on REMIX-technology (REgenerated MIXture of U and Pu oxides) the fuel composition is produced on the basis of a uranium and plutonium mixture from spent Light Water Reactor (LWR) fuel and additional natural uranium. In this case, there is some saving in the amount of natural uranium used. The basic features of the WWER-1000 fuel loadings with a new variant REMIX-fuel during multiple recycle in the closed nuclear fuel cycle are described in this paper. Such fuel compositions are produced on a basis of a uranium and plutonium mixture allocated at processing the spent fuel after irradiation in the WWER-1000 core, depleted uranium and fission material such as: 235U as a part of high-enriched uranium from the warheads superfluous for defense. Also here variants are considered of the perspective closed fuel cycle in which fissile feed materials for fuel manufacture is produced in the blankets of fast breeder reactors. The fissile material is 233U or Pu. The raw material is depleted uranium from the stocks of enrichment factories, or thorium. Natural uranium is not used in this case. The minimum feed material required for the REMIX technology in a closed fuel cycle was determined through calculations of different types of fissile and raw materials, with different cycle lengths and fuel-water ratios.

Optimization of the Mode of the Uranium-233 Accumulation for Application in Thorium Self-Sufficient Fuel Cycle of CANDU Power Reactor

2006 ◽  
Author(s):  
Boris Bergelson ◽  
Alexander Gerasimov ◽  
Georgy Tikhomirov
Keyword(s):  
Fuel Cycle ◽  
Power Reactor ◽  
Elementary Cell ◽  
Fissile Material ◽  
Optimum Ratio ◽  
Accumulation Time ◽  
Production Parameters ◽  
Active Core ◽  
The Cost ◽  
Thorium Cycle

Results of calculation studies of the first stage of self-sufficient thorium cycle for CANDU reactor are presented in the paper. The first stage is preliminary accumulation of 233U in the CANDU reactor itself. Parameters of active core and scheme of fuel reloading were accepted the same as those for CANDU reactor. It was assumed for calculations, that enriched 235U or plutonium was used as additional fissile material to provide neutrons for 233U production. Parameters of 10 different variants of the elementary cell of active core were calculated for the lattice pitch, geometry of fuel channels, and fuel assembly of the CANDU reactor. The results presented in the paper allow to determine the time of accumulation of the required amount of 233U and corresponding number of targets going into processing for 233U extraction. Optimum ratio of the accumulation time to number of processed targets can be determined using the cost of electric power produced by the reactor and cost of targets along with their processing.

Analysis of Sustainable Thorium Fuel Utilization in Molten Salt Reactors Starting From Enriched Uranium

2017 ◽  
Author(s):  
Deyang Cui ◽  
Xiangzhou Cai ◽  
Jingen Chen ◽  
Chenggang Yu
Keyword(s):  
Molten Salt ◽  
Fuel Cycle ◽  
Utilization Efficiency ◽  
Fissile Material ◽  
Fuel Utilization ◽  
Light Water ◽  
Waste Production ◽  
Water Reactors ◽  
Enriched Uranium ◽  
Two Stages

Molten salt reactor (MSR), as one of the six systems selected by the Generation IV International Forum (GIF) for future advantaged reactors research and development (R&D), has excellent performances such as high inherent safety, desirable breeding capacity, low radioactive waste production, flexible fuel cycle and non-proliferation. Meanwhile, thorium, as an appealing alternative nuclear fuel to uranium, is more abundant than uranium in the earth’s crust. Realization of thorium fuel cycle in MSRs will greatly contribute to sustainable energy supply for global development. The objective of this paper is to analyze and evaluate thorium fuel utilization in a program in which MSRs are expected to be developed step by step. The program can be described as follows: 1 The first stage is a converter reactor fueled with low enriched uranium. With limited processing based on current chemical partitioning technology and fuel-feeding techniques in the generation-I MSR; 2 The second stage is a 233U production reactor. By using the enriched uranium, it can produce 233U which does not exist in nature; 3 The third stage is a thorium breeding reactor. It is a breeder reactor with Th/233U fuel cycle, and sustainable thorium utilization for energy production is expected to be eventually realized. By employing an in-house developed tool based on SCALE6.1, the performance of MSR fueled with low enriched uranium is firstly assessed. It is found that MSR is attractive regarding conversion ratio when compared with light water reactors. Then we illustrate the feasibility of 233U production in MSR. Enriched uranium with two enrichments are used as driver fuels to start MSR and produce 233U. The results show that 233U production can be achieved and the double time is about 79.1 years for 20% enriched uranium and 28.3 years for 60% enriched uranium. Finally, the performance of MSR based on pure Th/233U fuel cycle is evaluated. It is found that breeding fissile material is possible in MSR and the breeding ratio is desirable (1.049). Comparison of the three-stage MSRs is also conducted and the results indicate that the resource utilization efficiency is much higher in stage-III than that in the first two stages and much less minor actinides is produced in MSR operating on Th/233U fuel cycle than that in traditional light water reactor.

scholarly journals Separation of Lanthanide Isotopes from Mixed Fission Product Samples

Separations ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 104
Author(s):  
Leah M. Arrigo ◽  
Jun Jiang ◽  
Zachary S. Finch ◽  
James M. Bowen ◽  
Staci M. Herman ◽  
...  
Keyword(s):  
Fission Product ◽  
Fission Products ◽  
Nuclear Data ◽  
Product Analysis ◽  
Data Production ◽  
Thermal Irradiation ◽  
Nuclear Events ◽  
Lanthanide Separation ◽  
Enriched Uranium ◽  
Fission Yields

The measurement of radioactive fission products from nuclear events has important implications for nuclear data production, environmental monitoring, and nuclear forensics. In a previous paper, the authors reported the optimization of an intra-group lanthanide separation using LN extraction resin from Eichrom Technologies®, Inc. and a nitric acid gradient. In this work, the method was demonstrated for the separation and quantification of multiple short-lived fission product lanthanide isotopes from a fission product sample produced from the thermal irradiation of highly enriched uranium. The separations were performed in parallel in quadruplicate with reproducible results and high decontamination factors for 153Sm, 156Eu, and 161Tb. Based on the results obtained here, the fission yields for 144Ce, 153Sm, 156Eu, and 161Tb are consistent with published fission yields. This work demonstrates the effectiveness of the separations for the intended application of short-lived lanthanide fission product analysis requiring high decontamination factors.

scholarly journals 10. General Discussion

1960 ◽  
Vol 10 ◽  
pp. 677-679 ◽  
Keyword(s):  
Yield Curve ◽  
Fission Products ◽  
Heavy Elements ◽  
Sikhote Alin ◽  
Heavy Nuclei ◽  
Fission Yield ◽  
Element Abundances ◽  
The Earth ◽  
R Process ◽  
Nova Outburst

1. p. SELINOV: Anomalous abundances of Te and Xe isotopes in meteorites and in the Earth permit us to draw some conclusions concerning the age of uranium and the processes of nucleogenesis. According to the estimate by Hoyle the amount of 254Cf disintegrated during a super-nova outburst is of the order of io29 g or io~4 of the stellar mass. According to the fission-yield curve the isotopes of Te comprise about 1 % of the mass of fission products. The abundances of Te 128-131 are anomalously high, due to the fission of heavy nuclei. The element abundances do not permit us to draw any conclusions about the r-process. The isotopes of Te and Xe with even mass numbers give evidence in favour of the r-process (anomalously high abundances). But the amount of Te in meteorites and in Earth is about 1000 times less than it should be if formed during the outburst. The Sikhote- Alin meteorite shows the same anomaly. We may conclude that the heavy elements of the solar system have been formed not in a single super-nova outburst, but as a result of mixing from the totality of outbursts. According to Hoyle, this gives a definite estimate for the age of uranium.

The commodification of personality: Human enhancement and market society

Human Affairs ◽  
2020 ◽  
Vol 31 (1) ◽  
pp. 40-45
Author(s):  
Leandro Gaitán
Keyword(s):  
New Technologies ◽  
Human Enhancement ◽  
The Self ◽  
Market Society ◽  
Technological Society ◽  
Technological Tools

Abstract In a future highly technological society it will be possible to modify the personality using different kinds of technological tools. Consequently, we could become buyers and consumers of personality. As such, personality, which is a core aspect of the self, could turn into a commodity. This article intends to address the following questions: 1) How can new technologies modify personality? 2) Why might personality become a commodity? 3) What is wrong with turning personality into commodity?

BIMODAL FISSION IN 258FM

1986 ◽  
Vol 01 (06) ◽  
pp. 377-381 ◽  
Author(s):  
K. DEPTA ◽  
J.A. MARUHN ◽  
W. GREINER ◽  
W. SCHEID ◽  
A. SANDULESCU
Keyword(s):  
Kinetic Energy ◽  
Shell Model ◽  
Fission Products ◽  
Degree Of Freedom ◽  
Total Kinetic Energy ◽  
Heavy Nuclei ◽  
Energy Distributions ◽  
Decay Channels ◽  
Symmetric Fission ◽  
Kinetic Energy Distributions

Within the 2-center shell model we present an explanation for the mass and total-kinetic-energy distributions of fission products of very heavy nuclei called “bimodal fission.” For the case of 258 FM we show that the symmetric fission can be described by a 2-dimensional treatment of the elongation and neck degree of freedom. Owing to shell corrections the system fissions via two decay channels that have distinct kinetic energies.

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