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01211 Research activities for accelerator-driven transmutation system at JAERI
05 Nuclear fuels (economics, policy, supplies, forecasts) 06101207 DMS
Development of medium and small sized reactors:
Tominaga, K. et al. Progress in Nuclear Energy, 2005, 47, (1 4), 106 114. Nuclear power is expected to become the main source for electric power generation in Japan for the reasons of energy security and prevention of CO2 emission. In addition, the slowdown of recent electric power demand and the liberalization of the electric power market are accelerating medium and small sized reactor development. Furthermore, the needs of medium and small sized reactors have become greater in foreign countries where electric grid systems are weak. Under these circumstances, Hitachi has developed DMS's (Double MS: Modular Simplified & Medium Small Reactors) as 400 MWe class LWR's supported by The Japan Atomic Power Company. In addition, DMS's have been designed based on proven technology that requires no large-scale development, and can therefore be introduced in the market in near future.
06101208
Gas cooled fast reactor for generation IV service
Hejzlar, P. et al. Progress in Nuclear Energy, 2005, 47, (1 4), 271 282. The gas cooled fast reactor (GFR), which is among the Generation IV concepts under evaluation for future deployment, will have to satisfy the Gen IV goals in the area of sustainability, safety and economy. This paper discusses challenges posed by the GFR when striving for the achievement of balance among the above Generation IV goals, and the pros and cons of various design choices. Considering these goals, the currently preferred design direction at MIT is a GFR design using a direct supercritical CO2 cycle, traditional containment with design pressure of 5 bars, employment of redundant active emergency cooling systems with highly reliable and diverse power supplies, which can also function in the passive mode as a backup at 5 bars containment pressure, and TRU fuelled cores using either block-type (TRU-U)C fuel or pin type (TRU-U)C fuel with double cladding or (TRU-U)O2 fuel vibropacked in a tube-in-duct assembly.
06101209
High temperature reactor development in China
Xu, Y. et al. Progress in Nuclear Energy, 2005, 47, (1 4), 260 270. Since the late 1970s the research and development program on the high temperature gas-cooled reactor (HTR) has been carried out in China. The 10 MW High Temperature Gas-cooled Reactor-Test Module (HTR-10) reached first criticality in 2000 and was put into full power operation in 2003. Six safety demonstration tests were done on the HTR-10. The project of the HTR-10 with a gas turbine cycle is underway. The project of the HTR demonstration plant with a power of around 150 MWe (HTR-PM) is planned. In this paper the HTR development in China is briefly described.
06101210 Proposal of utilization of nuclear spent fuels for gamma cells Horiuchi, N. et al. Solar Energy Materials and Solar Cells, 2005, 87, (1 4), 287 297. Large amounts of nuclear spent fuel are generated in nuclear power plants every year and stored in fuel storage facilities for 20 30 years until reprocessing. However, the spent fuel still has residual energies, such as high-temperature heat energy and high-intensity gamma radioactivity. The authors have examined the characteristics of solar cells exposed to gamma radiation for the development of gamma cells utilizing nuclear spent fuel. They used a highly intense °UCo gamma source as a suitable substitute for spent fuel due to safety concerns and convenience. Two representative types of solar cells, amorphous and crystalline cells, were examined and the current and voltage generated by each type were measured. In general, solar cells are largely insensitive to gamma radiation because the radiation passes through solar cells without imparting all of its energy. In order to enhance the sensitivity to radiation, the solar cells were coupled to CsI(T1), NaI(T1) and plastic scintillators. The study confirmed the following characteristics: (1) amorphous solar cells coupled to a CsI(T1) scintillator are able to generate a large amount of electric power, compared to crystaltype solar cells, (2) amorphous cells exhibit a good linear response to high-intensity gamma radiation and generate electric power almost in proportion to the volume of the scintillator used, (3) the generated electric power is independent of the incident angle of the gamma rays and the amount of power is determined only by the volume of the scintillator used. The electric power generated by a single solar cell is very small, but a large amount of electric power can be obtained by arranging many solar cells in stacks and combining their induced current or voltage and by operating the cells all day, as they are not affected by weather conditions. It was concluded that gamma cells utilizing the gamma radiation of nuclear spent fuel can be expected to be useful for electric power generation in the near future.
06/01211 Research activities for accelerator-driven transmutation system at JAERI Sasa, T. Progress in Nuclear Energy, 2005, 47, (1 4), 314 326.
182
Fuel and Energy Abstracts
May 2006
Japan atomic energy research institute (JAERI) performs research and development (R&D) for accelerator-driven systems (ADS) for transmutation of long-lived nuclides. To study the basic characteristics of ADS, transmutation experimental facility is proposed within the framework of the J-PARC project. The facility consists of two buildings, transmutation physics experimental facility to research the neutronics and the controllability of ADS and ADS target test facility for material irradiation and partial mockup of beam window. A comprehensive R&D program for future ADS plant is also underway in three technical fields: (1) accelerator, (2) lead-bismuth target/coolant and (3) subcritical core.
06•01212 Simulating structural collapse of a PWR containment Prinja, N. K. et al. Nuclear Engineering andDesign, 2005, 235, (17 19), 2033 2043. NNC Limited was sponsored by the Health & Safety Executive (UK) to conduct finite element analysis to simulate the over-pressurization tests conducted on a 1/4 scale model of a pre-stressed concrete containment vessel (PCCV) by Sandia National Laboratories. The tests and the results indicated three distinct stages of structural response as the vessel approached its failure load. The first stage was essentially an elastic response. The second stage displayed non-linear behaviour, which started after onset of substantial concrete cracking and involved local yielding or fracture of structural components. The third stage involved extensive concrete cracking and rapid increase in strains leading to global structural collapse. This paper discusses the engineering judgment used to develop the 3D finite element (FE) global model, which was successfully analysed to predict the failure mode. For the limit state test (LST), it was shown that the liner ruptures before structural collapse. For the structural failure mode test (SFMT), the asymmetric behaviour was successfully predicted, identifying the weak area in the vessel where the structural collapse was initiated. This was possible because the 3D model simulated the interaction of the essential structural features such as the tendons, buttresses, liner, penetrations and the basemat. Explicit modelling of the post-tensioned tendons allowed the model to accommodate frictional loss, simulating realistic reduction in the pre-stress levels in certain areas. Detailed modelling of the penetrations and buttresses simulated local stiffening of the cylindrical wall. The maximum deflection was expected at the mid-height of the wall in the area away from local stiffening and where the pre-stress levels had reduced due to friction. This weak area was identified by the FE model and was confirmed by the test.
06•01213 Strong motion waves estimation for seismic control of nuclear power plant Radeva, S. T. et al. Nuclear Engineering andDesign, 2005, 235, (17 19), 1977 1988. The problem of forecasting in general and in real-time of the behaviour of seismic wave is discussed. Seismic waves classification on the base of principle axis transformation and evolutionary power spectrum estimation is provided for it implementation in an intelligent hybrid model. A hybrid model for real-time forecasting of strong motion acceleration on the bases of general, tectonic, seismic and site parameters is developed, where neuro-fuzzy model is combined with long-range dependence time series analysis. Seismic control is realizing on the base of this forecasting. Suggested model helps for taking right decision for activating different devices and systems for passive, active or hybrid structural control for protection of high-risk structures like power plants, in particular nuclear power plants. The numerical simulation was made with different program packages like Fuzzy TECH 5.51, MatLab 6.5 and Simulink.
06•01214 system
The feasibility study on perfect burning reactor
Nakae, N. Progress in Nuclear Energy, 2005, 47, (1 4), 139 146. The system of 100% natural uranium burning with once-through fuel cycle is defined as the Perfect Burning Reactor System (PBRS). This kind of nuclear system can be expected to have some good characteristic such as resource efficiency, radiotoxicity reduction, proliferation and nuclear safety. Therefore, the feasibility of the concept is studied in this paper. The preliminary results show that the system of 100% natural uranium burning with once-through fuel cycle is physically possible with a plenty supply of external neutron, and that the system demands no activities concerning with fuel cycle such as uranium enrichment, fuel fabrication, spent fuel reprocessing and radioactive waste treatment. The study also quantitatively clarifies the external neutron source strength, the nuclear criticality safety, the demanded accelerator performance and the energy balance. In addition, the more precise analysis is requested for well understanding and improving the characteristic and economical rationality of the system.
Development of medium and small sized reactors:
Tominaga, K. et al. Progress in Nuclear Energy, 2005, 47, (1 4), 106 114. Nuclear power is expected to become the main source for electric power generation in Japan for the reasons of energy security and prevention of CO2 emission. In addition, the slowdown of recent electric power demand and the liberalization of the electric power market are accelerating medium and small sized reactor development. Furthermore, the needs of medium and small sized reactors have become greater in foreign countries where electric grid systems are weak. Under these circumstances, Hitachi has developed DMS's (Double MS: Modular Simplified & Medium Small Reactors) as 400 MWe class LWR's supported by The Japan Atomic Power Company. In addition, DMS's have been designed based on proven technology that requires no large-scale development, and can therefore be introduced in the market in near future.
06101208
Gas cooled fast reactor for generation IV service
Hejzlar, P. et al. Progress in Nuclear Energy, 2005, 47, (1 4), 271 282. The gas cooled fast reactor (GFR), which is among the Generation IV concepts under evaluation for future deployment, will have to satisfy the Gen IV goals in the area of sustainability, safety and economy. This paper discusses challenges posed by the GFR when striving for the achievement of balance among the above Generation IV goals, and the pros and cons of various design choices. Considering these goals, the currently preferred design direction at MIT is a GFR design using a direct supercritical CO2 cycle, traditional containment with design pressure of 5 bars, employment of redundant active emergency cooling systems with highly reliable and diverse power supplies, which can also function in the passive mode as a backup at 5 bars containment pressure, and TRU fuelled cores using either block-type (TRU-U)C fuel or pin type (TRU-U)C fuel with double cladding or (TRU-U)O2 fuel vibropacked in a tube-in-duct assembly.
06101209
High temperature reactor development in China
Xu, Y. et al. Progress in Nuclear Energy, 2005, 47, (1 4), 260 270. Since the late 1970s the research and development program on the high temperature gas-cooled reactor (HTR) has been carried out in China. The 10 MW High Temperature Gas-cooled Reactor-Test Module (HTR-10) reached first criticality in 2000 and was put into full power operation in 2003. Six safety demonstration tests were done on the HTR-10. The project of the HTR-10 with a gas turbine cycle is underway. The project of the HTR demonstration plant with a power of around 150 MWe (HTR-PM) is planned. In this paper the HTR development in China is briefly described.
06101210 Proposal of utilization of nuclear spent fuels for gamma cells Horiuchi, N. et al. Solar Energy Materials and Solar Cells, 2005, 87, (1 4), 287 297. Large amounts of nuclear spent fuel are generated in nuclear power plants every year and stored in fuel storage facilities for 20 30 years until reprocessing. However, the spent fuel still has residual energies, such as high-temperature heat energy and high-intensity gamma radioactivity. The authors have examined the characteristics of solar cells exposed to gamma radiation for the development of gamma cells utilizing nuclear spent fuel. They used a highly intense °UCo gamma source as a suitable substitute for spent fuel due to safety concerns and convenience. Two representative types of solar cells, amorphous and crystalline cells, were examined and the current and voltage generated by each type were measured. In general, solar cells are largely insensitive to gamma radiation because the radiation passes through solar cells without imparting all of its energy. In order to enhance the sensitivity to radiation, the solar cells were coupled to CsI(T1), NaI(T1) and plastic scintillators. The study confirmed the following characteristics: (1) amorphous solar cells coupled to a CsI(T1) scintillator are able to generate a large amount of electric power, compared to crystaltype solar cells, (2) amorphous cells exhibit a good linear response to high-intensity gamma radiation and generate electric power almost in proportion to the volume of the scintillator used, (3) the generated electric power is independent of the incident angle of the gamma rays and the amount of power is determined only by the volume of the scintillator used. The electric power generated by a single solar cell is very small, but a large amount of electric power can be obtained by arranging many solar cells in stacks and combining their induced current or voltage and by operating the cells all day, as they are not affected by weather conditions. It was concluded that gamma cells utilizing the gamma radiation of nuclear spent fuel can be expected to be useful for electric power generation in the near future.
06/01211 Research activities for accelerator-driven transmutation system at JAERI Sasa, T. Progress in Nuclear Energy, 2005, 47, (1 4), 314 326.
182
Fuel and Energy Abstracts
May 2006
Japan atomic energy research institute (JAERI) performs research and development (R&D) for accelerator-driven systems (ADS) for transmutation of long-lived nuclides. To study the basic characteristics of ADS, transmutation experimental facility is proposed within the framework of the J-PARC project. The facility consists of two buildings, transmutation physics experimental facility to research the neutronics and the controllability of ADS and ADS target test facility for material irradiation and partial mockup of beam window. A comprehensive R&D program for future ADS plant is also underway in three technical fields: (1) accelerator, (2) lead-bismuth target/coolant and (3) subcritical core.
06•01212 Simulating structural collapse of a PWR containment Prinja, N. K. et al. Nuclear Engineering andDesign, 2005, 235, (17 19), 2033 2043. NNC Limited was sponsored by the Health & Safety Executive (UK) to conduct finite element analysis to simulate the over-pressurization tests conducted on a 1/4 scale model of a pre-stressed concrete containment vessel (PCCV) by Sandia National Laboratories. The tests and the results indicated three distinct stages of structural response as the vessel approached its failure load. The first stage was essentially an elastic response. The second stage displayed non-linear behaviour, which started after onset of substantial concrete cracking and involved local yielding or fracture of structural components. The third stage involved extensive concrete cracking and rapid increase in strains leading to global structural collapse. This paper discusses the engineering judgment used to develop the 3D finite element (FE) global model, which was successfully analysed to predict the failure mode. For the limit state test (LST), it was shown that the liner ruptures before structural collapse. For the structural failure mode test (SFMT), the asymmetric behaviour was successfully predicted, identifying the weak area in the vessel where the structural collapse was initiated. This was possible because the 3D model simulated the interaction of the essential structural features such as the tendons, buttresses, liner, penetrations and the basemat. Explicit modelling of the post-tensioned tendons allowed the model to accommodate frictional loss, simulating realistic reduction in the pre-stress levels in certain areas. Detailed modelling of the penetrations and buttresses simulated local stiffening of the cylindrical wall. The maximum deflection was expected at the mid-height of the wall in the area away from local stiffening and where the pre-stress levels had reduced due to friction. This weak area was identified by the FE model and was confirmed by the test.
06•01213 Strong motion waves estimation for seismic control of nuclear power plant Radeva, S. T. et al. Nuclear Engineering andDesign, 2005, 235, (17 19), 1977 1988. The problem of forecasting in general and in real-time of the behaviour of seismic wave is discussed. Seismic waves classification on the base of principle axis transformation and evolutionary power spectrum estimation is provided for it implementation in an intelligent hybrid model. A hybrid model for real-time forecasting of strong motion acceleration on the bases of general, tectonic, seismic and site parameters is developed, where neuro-fuzzy model is combined with long-range dependence time series analysis. Seismic control is realizing on the base of this forecasting. Suggested model helps for taking right decision for activating different devices and systems for passive, active or hybrid structural control for protection of high-risk structures like power plants, in particular nuclear power plants. The numerical simulation was made with different program packages like Fuzzy TECH 5.51, MatLab 6.5 and Simulink.
06•01214 system
The feasibility study on perfect burning reactor
Nakae, N. Progress in Nuclear Energy, 2005, 47, (1 4), 139 146. The system of 100% natural uranium burning with once-through fuel cycle is defined as the Perfect Burning Reactor System (PBRS). This kind of nuclear system can be expected to have some good characteristic such as resource efficiency, radiotoxicity reduction, proliferation and nuclear safety. Therefore, the feasibility of the concept is studied in this paper. The preliminary results show that the system of 100% natural uranium burning with once-through fuel cycle is physically possible with a plenty supply of external neutron, and that the system demands no activities concerning with fuel cycle such as uranium enrichment, fuel fabrication, spent fuel reprocessing and radioactive waste treatment. The study also quantitatively clarifies the external neutron source strength, the nuclear criticality safety, the demanded accelerator performance and the energy balance. In addition, the more precise analysis is requested for well understanding and improving the characteristic and economical rationality of the system.