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02041 Strategic thinking about nuclear energy: implications of the emerging market structure in electric generation
06
subcritical assembly consisting of thorium or another fertile element. This assembly during operation would burn all unwanted actinides and is able to incinerate long-lived radioactive fission products. The energy amplifier could produce energy much cheaper than nuclear or conventional power plants and more safely than other forms such as coal plants.
Interaction between natural convection and condensation heat transfer in the passive containment cooling condensers of the ESBWR reactor
99l02035
Mutioz-Cobo, J. L. et al. Annals of Nuclear Energy, 1999, 26, (4), 277-300. The crucial aspect of several new reactor designs is the passive containment cooling condenser (PCCC). In this paper several models have been developed to compute the heat transfer coefficients for the following cases: (i) condensation in the presence of non-condensable gases inside the PCCC tubes; (ii) laminar natural convection for vertical cylinders; (iii) turbulent natural convection for vertical cylinders. These models have been implemented in the TRAC-BFI code and the interaction between the conservation regime inside the condenser tubes and the natural convection outside have been studied.
Electrical power supply and utilization (scientific, technical)
relative to gas, coal and light water reactors and are likely to continue being so for the next few decades. However, due to global depletion of low-cost fossil fuel reserves and the problem of greenhouse gas emissions, the breeder represents the most assured and widely available long-term energy resource for many centuries. The policy problem is to establish a workable course and justification for near-term development prior to the era of economically viable breeders. In this paper, ten criteria that can influence decision making on national goals and paths to be followed are proposed and a basic multi-attribute evaluation model for a national decision process is described. A sample of typical inputs for five different national viewpoints is tabulated. Options for national and international strategies for long-term development are identified, covering a wide range of rates of expenditures. Burner reactors for power production and for highly secure sequestering of weapons plutonium appear to provide the most viable and important interim use and development path for fast reactors. A multinational pattern of development is expected to have political, economic and security advantages, as well as a better technical basis compared with isolated developments in individual countries.
99102036
99l92040 Stochastic simulation of a nuclear reaction driven chemical and diffusive process in a fusion reactor blanket
Hwang, W. et al. Nucl. Technol., 1998, 123, (2), 130-141. In the metal fuel performance analysis (computer) code for simulating the in-reactor behaviour under steady-state conditions (MACSIS), computational models for analysing in-reactor behaviour of metallic fuel pins in liquid-metal reactors under steady-state conditions are developed and implemented. Sodium logging and constituent redistribution effects are considered in calculating the temperature profile. The model for the radial redistribution of the fuel constituent is based on the thermotransport theory. Taking multibubble size distribution into account, the fission gas release model characterizes the lenticular bubble shape and the saturation condition on the grain boundary. Finally, the clad strains are calculated from the amount of fission gas released and interface pressure. In order to verify each model, sample calculations are performed and the results show that the MACSIS predictions generally agree well with the available irradiation data.
99102041 Strategic thinking about nuclear energy: Implications of the emerging market structure in electric generation
MACSIS: a metallic fuel performance snalysis code for simulating in-reactor behavior under steady-state conditions
3-D Monte Carlo and discrete ordinates void coefficient analysis for the Los Alamos National Laboratory Omega West reactor using MCNP and THREEDANT
99102037
Durkee, Jr., J. W. et al. Progress in Nuclear Energy, 1999, 34, (2), 99-142 Void coefficient behaviour for three experimental channels and several fuel assemblies in the Los Alamos Omega West nuclear reactor using MCNP and THREEDANT are characterized in this paper. Three-dimensional Monte Carlo and discrete ordinates computational modelling techniques were used. Good agreement was observed in void coefficient behaviour predicted by MCNP and THREEDANT. The experimental-channel grossvoiding calculations predict the existence of positive void coefficients due to overmoderation conditions. The fuel assemblies exhibit, for the most part, negative void coefficients, although the possibility of localized small positive void coefficients for one of the five assemblies analysed is indicated.
Koreshi, Z. U. Progress in Nuclear Energy, 1999, 34, (2), 147-170. The stochastic evolution of tritium in a fusian blanket resulting from the neutronic capture in lithium atoms and subsequent diffusion and chemical reaction of tritium itself is studied. Since the characteristic times for the three physical phenomena namely nuclear reaction, spatial diffusion and chemical reaction are orders of magnitude different from each other, a stochastic simulation can improve the computational efficiency of a straight-forward deterministic approach. In this work, a joint probability distribution is used to sample for diffusion and chemical reaction, given the nuclear ‘source term’. Thus the stochastic time evolution of tritium in a fusion blanket module can be estimated. With appropriate data for tritium processes, the application given here can be used to simulate the evolution of tritium in complex systems.
Bodde, D. L. Energy Policy, 1998, 26, (12) 957-962. Strong motivation is provided by global environmental concerns for electric generating technologies that reduce greenhouse gas emissions. By itself, however, this incentive is probably not sufficient to reverse the long-term decline in the market share of nuclear energy. This is because the power plants now offered by the nuclear vendors mesh poorly with the needs of competitive generating markets. Where managers of generating companies are held accountable to share owners in a competitive environment, the nuclear power plants now offered in the market for new generating capacity are at a distinct disadvantage. As much of the world moves toward the competitive model, this disadvantage will become increasingly limiting. An alternative nuclear power plant concept and fuel cycle is needed, a radical departure from current practice, designed with the competitive marketplace in mind. To accomplish this, a new kind of institution is required: multinational in scope, oriented toward the market and able to master the politics of the fuel cycle.
Neutronic analysis of a thorium fusion breeder with enhanced protection against nuclear weapon proliferation
99lQ2038
Sahin, S. and Yapici, H. Annals of Nuclear Energy, 1999, 26, (l), 13-27. An analysis is made of the fissile breeding capability of a (D, T) fusionfission (hybrid) reactor fuelled with thorium in order to provide nuclear fuel for light water reactors (LWRs). Three different fertile material compositions are investigated for fissile fuel breeding and two different coolants for the nuclear heat transfer out of the fissile fuel breeding zone. Depending on the type of the coolant in the fission zone, fusion power plant operation periods between 30 and 48 months are evaluated to achieve a fissile fuel enrichment quality between 3 and 4%, under a first-wall fusion neutron energy load of 5 MW/m* and a plant factor of 75%. Flibe coolant is superior to helium with regard to fissile fuel breeding. During a plant operation over four years, enrichment grades between 3.0 and 5.8% are calculated for different fertile fuel and coolant compositions. A fusion breeder with ThOz produces weapon grade 233U. The denaturation of the 233U fuel is realized with a homogenous mixture of 90% ThOz with 10% natural-UOz as well as with 10% LWR spent nuclear fuel. The homogenous mixture of 90% ThOz with 10% natural-UOz can successfully denaturate 233U with 238U. The uranium component of the mixture remains denaturated over the entire plant operation period of 48 months. However, at the early stages of plant operation, the generated plutonium component is of weapon grade quality. The plutonium component can be denaturated after a plant operation period of 24 and 30 months in Flibe cooled and helium cooled blankets, respectively. On the other hand, the homogenous mixture of 90% ThOz with 10% LWR spent nuclear fuel remains non-prolific over the entire period for both uranium and plutonium components.
Options for further developments of fast reactors 99102039 Zaleski, C.-P. and Zebroski, E. L. Energy, (Oxford), 1998, 23, (7/5), 549569. The declining rates of growth of nuclear capacity and an increasing backlog of uranium and plutonium reserves has meant that the commercial use of breeder reactors has been delayed. They are not economically competitive
06
ELECTRICAL POWER SUPPLY AND UTILIZATION Scientific, Technical
99102042
Abrasion
and
endanger
of taper
gear
in
transmission
Zhang, Q. and Cai, C. Jinshu Rechuli, 1998, (2), 39-40, 52. (In Chinese) Macro-scope fractography, SEM, transmission electron microscope, metallurgical microscope and microhardness measurement were all used to study the failure of taper gears of coal whipper drag accelerators used in a steam power plant. The failure form of the taper gear was mechanical peeling off by alternate contact stress and fracture by abrasion. Friction heat worsened the quality of lubricating oil and affected the lubricating function.
99102043 Anti-corrosion fossil power plant
technology for life extension
of
Ha, J. S. Han’guk Pusik Hokhoechi, 1998, 27, (3), 331-338. (In Korean) Nowadays, many fossil power plants have been in operation for such a long time that they are currently being used beyond their expected design life. Therefore the failures of these plants are discussed so that engineers take into account the development of life extension technique. The main concern in old power plants is corrosion and causes of breakdown can be stress corrosion cracking, caustic attack, oxygen pitting, hydrogen damage, high
Fuel and Energy Abstracts
May 1999 299
subcritical assembly consisting of thorium or another fertile element. This assembly during operation would burn all unwanted actinides and is able to incinerate long-lived radioactive fission products. The energy amplifier could produce energy much cheaper than nuclear or conventional power plants and more safely than other forms such as coal plants.
Interaction between natural convection and condensation heat transfer in the passive containment cooling condensers of the ESBWR reactor
99l02035
Mutioz-Cobo, J. L. et al. Annals of Nuclear Energy, 1999, 26, (4), 277-300. The crucial aspect of several new reactor designs is the passive containment cooling condenser (PCCC). In this paper several models have been developed to compute the heat transfer coefficients for the following cases: (i) condensation in the presence of non-condensable gases inside the PCCC tubes; (ii) laminar natural convection for vertical cylinders; (iii) turbulent natural convection for vertical cylinders. These models have been implemented in the TRAC-BFI code and the interaction between the conservation regime inside the condenser tubes and the natural convection outside have been studied.
Electrical power supply and utilization (scientific, technical)
relative to gas, coal and light water reactors and are likely to continue being so for the next few decades. However, due to global depletion of low-cost fossil fuel reserves and the problem of greenhouse gas emissions, the breeder represents the most assured and widely available long-term energy resource for many centuries. The policy problem is to establish a workable course and justification for near-term development prior to the era of economically viable breeders. In this paper, ten criteria that can influence decision making on national goals and paths to be followed are proposed and a basic multi-attribute evaluation model for a national decision process is described. A sample of typical inputs for five different national viewpoints is tabulated. Options for national and international strategies for long-term development are identified, covering a wide range of rates of expenditures. Burner reactors for power production and for highly secure sequestering of weapons plutonium appear to provide the most viable and important interim use and development path for fast reactors. A multinational pattern of development is expected to have political, economic and security advantages, as well as a better technical basis compared with isolated developments in individual countries.
99102036
99l92040 Stochastic simulation of a nuclear reaction driven chemical and diffusive process in a fusion reactor blanket
Hwang, W. et al. Nucl. Technol., 1998, 123, (2), 130-141. In the metal fuel performance analysis (computer) code for simulating the in-reactor behaviour under steady-state conditions (MACSIS), computational models for analysing in-reactor behaviour of metallic fuel pins in liquid-metal reactors under steady-state conditions are developed and implemented. Sodium logging and constituent redistribution effects are considered in calculating the temperature profile. The model for the radial redistribution of the fuel constituent is based on the thermotransport theory. Taking multibubble size distribution into account, the fission gas release model characterizes the lenticular bubble shape and the saturation condition on the grain boundary. Finally, the clad strains are calculated from the amount of fission gas released and interface pressure. In order to verify each model, sample calculations are performed and the results show that the MACSIS predictions generally agree well with the available irradiation data.
99102041 Strategic thinking about nuclear energy: Implications of the emerging market structure in electric generation
MACSIS: a metallic fuel performance snalysis code for simulating in-reactor behavior under steady-state conditions
3-D Monte Carlo and discrete ordinates void coefficient analysis for the Los Alamos National Laboratory Omega West reactor using MCNP and THREEDANT
99102037
Durkee, Jr., J. W. et al. Progress in Nuclear Energy, 1999, 34, (2), 99-142 Void coefficient behaviour for three experimental channels and several fuel assemblies in the Los Alamos Omega West nuclear reactor using MCNP and THREEDANT are characterized in this paper. Three-dimensional Monte Carlo and discrete ordinates computational modelling techniques were used. Good agreement was observed in void coefficient behaviour predicted by MCNP and THREEDANT. The experimental-channel grossvoiding calculations predict the existence of positive void coefficients due to overmoderation conditions. The fuel assemblies exhibit, for the most part, negative void coefficients, although the possibility of localized small positive void coefficients for one of the five assemblies analysed is indicated.
Koreshi, Z. U. Progress in Nuclear Energy, 1999, 34, (2), 147-170. The stochastic evolution of tritium in a fusian blanket resulting from the neutronic capture in lithium atoms and subsequent diffusion and chemical reaction of tritium itself is studied. Since the characteristic times for the three physical phenomena namely nuclear reaction, spatial diffusion and chemical reaction are orders of magnitude different from each other, a stochastic simulation can improve the computational efficiency of a straight-forward deterministic approach. In this work, a joint probability distribution is used to sample for diffusion and chemical reaction, given the nuclear ‘source term’. Thus the stochastic time evolution of tritium in a fusion blanket module can be estimated. With appropriate data for tritium processes, the application given here can be used to simulate the evolution of tritium in complex systems.
Bodde, D. L. Energy Policy, 1998, 26, (12) 957-962. Strong motivation is provided by global environmental concerns for electric generating technologies that reduce greenhouse gas emissions. By itself, however, this incentive is probably not sufficient to reverse the long-term decline in the market share of nuclear energy. This is because the power plants now offered by the nuclear vendors mesh poorly with the needs of competitive generating markets. Where managers of generating companies are held accountable to share owners in a competitive environment, the nuclear power plants now offered in the market for new generating capacity are at a distinct disadvantage. As much of the world moves toward the competitive model, this disadvantage will become increasingly limiting. An alternative nuclear power plant concept and fuel cycle is needed, a radical departure from current practice, designed with the competitive marketplace in mind. To accomplish this, a new kind of institution is required: multinational in scope, oriented toward the market and able to master the politics of the fuel cycle.
Neutronic analysis of a thorium fusion breeder with enhanced protection against nuclear weapon proliferation
99lQ2038
Sahin, S. and Yapici, H. Annals of Nuclear Energy, 1999, 26, (l), 13-27. An analysis is made of the fissile breeding capability of a (D, T) fusionfission (hybrid) reactor fuelled with thorium in order to provide nuclear fuel for light water reactors (LWRs). Three different fertile material compositions are investigated for fissile fuel breeding and two different coolants for the nuclear heat transfer out of the fissile fuel breeding zone. Depending on the type of the coolant in the fission zone, fusion power plant operation periods between 30 and 48 months are evaluated to achieve a fissile fuel enrichment quality between 3 and 4%, under a first-wall fusion neutron energy load of 5 MW/m* and a plant factor of 75%. Flibe coolant is superior to helium with regard to fissile fuel breeding. During a plant operation over four years, enrichment grades between 3.0 and 5.8% are calculated for different fertile fuel and coolant compositions. A fusion breeder with ThOz produces weapon grade 233U. The denaturation of the 233U fuel is realized with a homogenous mixture of 90% ThOz with 10% natural-UOz as well as with 10% LWR spent nuclear fuel. The homogenous mixture of 90% ThOz with 10% natural-UOz can successfully denaturate 233U with 238U. The uranium component of the mixture remains denaturated over the entire plant operation period of 48 months. However, at the early stages of plant operation, the generated plutonium component is of weapon grade quality. The plutonium component can be denaturated after a plant operation period of 24 and 30 months in Flibe cooled and helium cooled blankets, respectively. On the other hand, the homogenous mixture of 90% ThOz with 10% LWR spent nuclear fuel remains non-prolific over the entire period for both uranium and plutonium components.
Options for further developments of fast reactors 99102039 Zaleski, C.-P. and Zebroski, E. L. Energy, (Oxford), 1998, 23, (7/5), 549569. The declining rates of growth of nuclear capacity and an increasing backlog of uranium and plutonium reserves has meant that the commercial use of breeder reactors has been delayed. They are not economically competitive
06
ELECTRICAL POWER SUPPLY AND UTILIZATION Scientific, Technical
99102042
Abrasion
and
endanger
of taper
gear
in
transmission
Zhang, Q. and Cai, C. Jinshu Rechuli, 1998, (2), 39-40, 52. (In Chinese) Macro-scope fractography, SEM, transmission electron microscope, metallurgical microscope and microhardness measurement were all used to study the failure of taper gears of coal whipper drag accelerators used in a steam power plant. The failure form of the taper gear was mechanical peeling off by alternate contact stress and fracture by abrasion. Friction heat worsened the quality of lubricating oil and affected the lubricating function.
99102043 Anti-corrosion fossil power plant
technology for life extension
of
Ha, J. S. Han’guk Pusik Hokhoechi, 1998, 27, (3), 331-338. (In Korean) Nowadays, many fossil power plants have been in operation for such a long time that they are currently being used beyond their expected design life. Therefore the failures of these plants are discussed so that engineers take into account the development of life extension technique. The main concern in old power plants is corrosion and causes of breakdown can be stress corrosion cracking, caustic attack, oxygen pitting, hydrogen damage, high
Fuel and Energy Abstracts
May 1999 299