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00198 Cryotechnology for Wendelstein 7-X
05
Nuclear
fuels
(scientific,
technical)
This work proposes a new potential application of waste coal fly ash as a K fertilizer support. Fly ash was reacted with KOH to facilitate the impregnation of K as well as to enhance the bonding force. In particular, the applied process resulted in a significant slow-releasing characteristic of fertilizer elements. To examine the effect of K impregnation, a few detailed leaching tests were carried out in terms of process variables such as reaction time and temperature, sintering time and temperature, and KOH concentration. The current experiment presented an optimum preparation condition that is competitive with conventional compound fertilizers. The manufactured ash fertilizers inhibited release of the K elements. It was also found through the continuous leaching test with pure water that the ash fertilizer had excellent moisture absorbability. However, the effects of some trace elements in fly ash on soil health and crop productivity as well as environmental considerations need to be established with longterm studies.
to several thousand atomic parts per million (appm) of hydrogen and helium were produced in the irradiated material via spallation reactions. Results of tensile tests at temperatures from room temperature up to 164°C show large increases in tensile yield strength, small increases in ultimate tensile strength, reductions in strain hardening capacity and reductions in ductility (uniform elongation and strain-to-necking) with increasing irradiation dose. A comparison of these data with the large database on tensile properties of type 316 stainless steel exposed to fission neutrons and tensile tested over the same temperature range show similar trends with regard to strength changes, but significantly larger reductions in ductility with irradiation dose were observed after irradiation in the spallation environment. The much higher amounts of helium and hydrogen produced through spallation in the LANSCE spectrum, compared to those developed in fission neutron irradiation environments at equivalent doses, may contribute to degradation in ductility.
04/00194 Vibration consistency prediction model for rollercompacted concrete Khunthongkeaw, J. and Tangtermsirikul, S. AC1 Materials Journal, 2003, 100, (l), 3-13. During recent years, fly ash concrete has become popular in the concrete industry in Thailand, with its expected consumption in the year 2003 exceeding 2 million tons from the total annual production of -3 million tons. Recently, a huge roller-compacted concrete (RCC) project (Ta Dan Dam) was started in Thailand - the volume was considered the current largest in the world at 5 000 000 m3. One of the main problems still concerns the mixture proportioning, however. Various parameters influencing the consistency of RCC are used for predicting its consistency. Those parameters are the ratio of paste volume-to-void content of densely compacted aggregate phase, free water content, and physical properties of solid materials. A model for predicting Vebe time of RCC was formulated and verified with the actual results. This model could be used to predict the Vebe time of RCC with satisfactory accuracy.
04/00197 Criteria for nuclear emission by bubble implosion Ohta, T. International Journal of Hydrogen Energy, 2003, 28, (9), 101 l1014. A dynamic model for nuclear emission by implosion of cavitation bubble is proposed, and the criteria (realizing conditions) for nuclear reaction are discussed by the methods of molecular kinetics. The hot core, in which the D+- Df fusion may take place, has to have the minimum limit for its size, and the core radius with less than a few 10e6 m cannot give rise to nuclear emission for CsDsO. There exist two critical radii, that is, the initial and upper critical radius for the bubble as well as the lower critical radius for the core (the final bubble). The upper critical radius must be several times larger than 10m3 m. The relationships between the critical radii and the critical temperature are discussed. The confining time of the plasma energy in the core is calculated by the energy loss rate, and it is concluded that the nuclear reaction may be possible if both the radii are adequately large. Possibility of self-reproduction of the nuclear reaction is also discussed.
05 NUCLEAR FUELS
04/00198 Cryotechnology for Wendelstein 7-X Schauer, F. Fusion Engineering and Design, 2003, 66-68, 1045-1048. For the underlying task to cool the Wendelstein 7-X (W7-X) superconducting coil conductors and the divertor cryo-pumps, an extended cryo-system is required. Besides the magnet coils and cryo-pumps proper, the coil housings and supports, the thermal shields of the cryostat and cryo-pumps, and the current leads have to be cooled. This is achieved by a refrigeration plant including coolant transfer lines and distribution boxes, and a widespread pipework within the cryostat. All these components are finally defined, and purchase actions are under way.
Scientific, technical 04/00195 Application of the local fracture stress model on the cleavage fracture of the reactor pressure vessel steels in the transition temperature region Yang, W.-J. et al. Journal of Nuclear Materials, 2003, 311, (2-3), 234242. The fracture toughness in the ductile-brittle transition region of reactor pressure vessel steels was evaluated by means of an RKR-type model which describes the temperature dependence of the cleavage fracture toughness based on the constant fracture stress cr. The fracture stress gf and the characteristic distance are two main parameters in the RKR model. In order to apply the RKR model to the transition temperature region, these two parameters were investigated in different manners. In this study, the local fracture stress, Q*, was determined from the pre-cracked specimens. The results showed that the local fracture stress ufati determined from the pre-cracked specimens was higher than the fracture stress Q from the notched specimens, while those values were practically independent of the temperatures. The CID (cleavage initiation distance), which represents the distance from the crack tip to the cleavage initiation site, was measured in every fractured specimen. The measured CID values were strongly dependent on the test temperatures. Besides, the fracture toughness K,c in the transition region was dependent on the measured CID. The RKR model, when the local fracture stress gr* and the measured CIDs were applied, could describe the temperature dependency of the median transition fracture toughness KJc(,,dj. 04/00196 spallation of type Malay, As part neutron 316LN spallation Neutron maximum addition 24
Comparison of fission neutron and proton/ neutron irradiation effects on the tensile behavior 316 and 304 stainless steel S. A. et al. Journal of Nuclear Materials, 2003, 318, 283-291. of the accelerator production of tritium and the spallation source programmes, the tensile properties of annealed 304L, and 316L stainless steel have been measured after proton and neutron irradiation in the target region of the Los Alamos Science Centre (LANSCE) accelerator (800 MeV, 1 mA) to a dose of 12 dpa at temperatures ranging from 30 to 120°C. In to the displacement damage produced from the irradiation, up
Fuel
and
Energy
Abstracts
January
2004
04/00199 Fast-neutron and gamma-ray transmission method for coke-humidity determination Cywicka-Jakiel, T. Applied Energy, 2003, 74, (3-4), 305-3 11, Efficient and highly automated metallurgical processes require the online control of coke moisture which assures high steel quality and fuel economy. The present paper dealt with the feasibility study of the fast neutron and gamma-ray transmission (FNGT) technique for the determination of the moisture content of coke in a hopper-mounted gauge arrangement. In the experimental assembly3 a Pu-Be source was used. Two separate detectors: @25x120 mm He (surrounded by paraffin moderator) and (z1100x100 mm NaI(T1) were applied. The temperature of the moderator was controlled and a suitable correction of the neutron count rate was done as the hydrogen H capture crosssection shows a l/v dependence, where v is the neutron velocity. The optimization of the FNGT arrangement was done by the modelling calculations using MCNP 4C code and was focused on obtaining a high sensitivity of the transmitted neutron flux to the moisture changes and on lowering the neutron-counting error, both leading to a more accurate humidity determination. Laboratory measurements were carried out for lump-coke and crushed-coke samples, with added moisture up to 8 wt% and 17.1 wt% respectively, and showed a good agreement between the moisture content determined from the FNGT measurements and the moisture determined from an oven-drying method. 04100200 Hydrogen, nuclear energy, and the advanced high-temperature reactor Forsberg, C. VI. International Journal of Hydrogen Energy, 2003, 28, (lo), 1073-1081. Nuclear energy has been proposed as an energy source to produce hydrogen (Hz) from water. An examination of systems issues in this paper indicates that the infrastructure of Ha consumption is now compatible with the production of Hz by nuclear reactors. Alternative H2 production processes were examined to define the requirements such processes would impose on the nuclear reactor. These requirements include supplying heat at a near-constant high temperature, providing a low-pressure interface with the HZ production processes, isolating the nuclear plant from the chemical plant, and avoiding
Nuclear
fuels
(scientific,
technical)
This work proposes a new potential application of waste coal fly ash as a K fertilizer support. Fly ash was reacted with KOH to facilitate the impregnation of K as well as to enhance the bonding force. In particular, the applied process resulted in a significant slow-releasing characteristic of fertilizer elements. To examine the effect of K impregnation, a few detailed leaching tests were carried out in terms of process variables such as reaction time and temperature, sintering time and temperature, and KOH concentration. The current experiment presented an optimum preparation condition that is competitive with conventional compound fertilizers. The manufactured ash fertilizers inhibited release of the K elements. It was also found through the continuous leaching test with pure water that the ash fertilizer had excellent moisture absorbability. However, the effects of some trace elements in fly ash on soil health and crop productivity as well as environmental considerations need to be established with longterm studies.
to several thousand atomic parts per million (appm) of hydrogen and helium were produced in the irradiated material via spallation reactions. Results of tensile tests at temperatures from room temperature up to 164°C show large increases in tensile yield strength, small increases in ultimate tensile strength, reductions in strain hardening capacity and reductions in ductility (uniform elongation and strain-to-necking) with increasing irradiation dose. A comparison of these data with the large database on tensile properties of type 316 stainless steel exposed to fission neutrons and tensile tested over the same temperature range show similar trends with regard to strength changes, but significantly larger reductions in ductility with irradiation dose were observed after irradiation in the spallation environment. The much higher amounts of helium and hydrogen produced through spallation in the LANSCE spectrum, compared to those developed in fission neutron irradiation environments at equivalent doses, may contribute to degradation in ductility.
04/00194 Vibration consistency prediction model for rollercompacted concrete Khunthongkeaw, J. and Tangtermsirikul, S. AC1 Materials Journal, 2003, 100, (l), 3-13. During recent years, fly ash concrete has become popular in the concrete industry in Thailand, with its expected consumption in the year 2003 exceeding 2 million tons from the total annual production of -3 million tons. Recently, a huge roller-compacted concrete (RCC) project (Ta Dan Dam) was started in Thailand - the volume was considered the current largest in the world at 5 000 000 m3. One of the main problems still concerns the mixture proportioning, however. Various parameters influencing the consistency of RCC are used for predicting its consistency. Those parameters are the ratio of paste volume-to-void content of densely compacted aggregate phase, free water content, and physical properties of solid materials. A model for predicting Vebe time of RCC was formulated and verified with the actual results. This model could be used to predict the Vebe time of RCC with satisfactory accuracy.
04/00197 Criteria for nuclear emission by bubble implosion Ohta, T. International Journal of Hydrogen Energy, 2003, 28, (9), 101 l1014. A dynamic model for nuclear emission by implosion of cavitation bubble is proposed, and the criteria (realizing conditions) for nuclear reaction are discussed by the methods of molecular kinetics. The hot core, in which the D+- Df fusion may take place, has to have the minimum limit for its size, and the core radius with less than a few 10e6 m cannot give rise to nuclear emission for CsDsO. There exist two critical radii, that is, the initial and upper critical radius for the bubble as well as the lower critical radius for the core (the final bubble). The upper critical radius must be several times larger than 10m3 m. The relationships between the critical radii and the critical temperature are discussed. The confining time of the plasma energy in the core is calculated by the energy loss rate, and it is concluded that the nuclear reaction may be possible if both the radii are adequately large. Possibility of self-reproduction of the nuclear reaction is also discussed.
05 NUCLEAR FUELS
04/00198 Cryotechnology for Wendelstein 7-X Schauer, F. Fusion Engineering and Design, 2003, 66-68, 1045-1048. For the underlying task to cool the Wendelstein 7-X (W7-X) superconducting coil conductors and the divertor cryo-pumps, an extended cryo-system is required. Besides the magnet coils and cryo-pumps proper, the coil housings and supports, the thermal shields of the cryostat and cryo-pumps, and the current leads have to be cooled. This is achieved by a refrigeration plant including coolant transfer lines and distribution boxes, and a widespread pipework within the cryostat. All these components are finally defined, and purchase actions are under way.
Scientific, technical 04/00195 Application of the local fracture stress model on the cleavage fracture of the reactor pressure vessel steels in the transition temperature region Yang, W.-J. et al. Journal of Nuclear Materials, 2003, 311, (2-3), 234242. The fracture toughness in the ductile-brittle transition region of reactor pressure vessel steels was evaluated by means of an RKR-type model which describes the temperature dependence of the cleavage fracture toughness based on the constant fracture stress cr. The fracture stress gf and the characteristic distance are two main parameters in the RKR model. In order to apply the RKR model to the transition temperature region, these two parameters were investigated in different manners. In this study, the local fracture stress, Q*, was determined from the pre-cracked specimens. The results showed that the local fracture stress ufati determined from the pre-cracked specimens was higher than the fracture stress Q from the notched specimens, while those values were practically independent of the temperatures. The CID (cleavage initiation distance), which represents the distance from the crack tip to the cleavage initiation site, was measured in every fractured specimen. The measured CID values were strongly dependent on the test temperatures. Besides, the fracture toughness K,c in the transition region was dependent on the measured CID. The RKR model, when the local fracture stress gr* and the measured CIDs were applied, could describe the temperature dependency of the median transition fracture toughness KJc(,,dj. 04/00196 spallation of type Malay, As part neutron 316LN spallation Neutron maximum addition 24
Comparison of fission neutron and proton/ neutron irradiation effects on the tensile behavior 316 and 304 stainless steel S. A. et al. Journal of Nuclear Materials, 2003, 318, 283-291. of the accelerator production of tritium and the spallation source programmes, the tensile properties of annealed 304L, and 316L stainless steel have been measured after proton and neutron irradiation in the target region of the Los Alamos Science Centre (LANSCE) accelerator (800 MeV, 1 mA) to a dose of 12 dpa at temperatures ranging from 30 to 120°C. In to the displacement damage produced from the irradiation, up
Fuel
and
Energy
Abstracts
January
2004
04/00199 Fast-neutron and gamma-ray transmission method for coke-humidity determination Cywicka-Jakiel, T. Applied Energy, 2003, 74, (3-4), 305-3 11, Efficient and highly automated metallurgical processes require the online control of coke moisture which assures high steel quality and fuel economy. The present paper dealt with the feasibility study of the fast neutron and gamma-ray transmission (FNGT) technique for the determination of the moisture content of coke in a hopper-mounted gauge arrangement. In the experimental assembly3 a Pu-Be source was used. Two separate detectors: @25x120 mm He (surrounded by paraffin moderator) and (z1100x100 mm NaI(T1) were applied. The temperature of the moderator was controlled and a suitable correction of the neutron count rate was done as the hydrogen H capture crosssection shows a l/v dependence, where v is the neutron velocity. The optimization of the FNGT arrangement was done by the modelling calculations using MCNP 4C code and was focused on obtaining a high sensitivity of the transmitted neutron flux to the moisture changes and on lowering the neutron-counting error, both leading to a more accurate humidity determination. Laboratory measurements were carried out for lump-coke and crushed-coke samples, with added moisture up to 8 wt% and 17.1 wt% respectively, and showed a good agreement between the moisture content determined from the FNGT measurements and the moisture determined from an oven-drying method. 04100200 Hydrogen, nuclear energy, and the advanced high-temperature reactor Forsberg, C. VI. International Journal of Hydrogen Energy, 2003, 28, (lo), 1073-1081. Nuclear energy has been proposed as an energy source to produce hydrogen (Hz) from water. An examination of systems issues in this paper indicates that the infrastructure of Ha consumption is now compatible with the production of Hz by nuclear reactors. Alternative H2 production processes were examined to define the requirements such processes would impose on the nuclear reactor. These requirements include supplying heat at a near-constant high temperature, providing a low-pressure interface with the HZ production processes, isolating the nuclear plant from the chemical plant, and avoiding