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06026 Discontinuous variational solutions for the neutron diffusion equation
05
Concept on coupled spectrum B/l (burnln and/or 96106024 transmutation) reactor for treatment of minor actlnldes % y thermal and fast neutrons Aziz, F. and Kitamoto, A. Ann. Nucl. Energy, Oct. 1996, 23, (15), 1239-1248. A conceptual design of B/T (burning and/or transmutation) reactor based on a modified conventional 1150 MWe-PWR system, with core consisted of two concentric regions for thermal and fast neutrons was proposed herein for Bn treatment of MA (minor actinides).
Control of a copper laser using neural networks 96106026 Buckley, J. M. and Richardson, M. B. Computing & Conrrol Engineering J., Jun. 1996, 7, (3), 145-152. Urenco (Capenhurst) Ltd. has been running high-power copper lasers several years owing to an interest in selective photo-ionisation for commercial enrichment. The main advantages of these lasers as pump sources for this process are their efficiency at high power and their high pulse repetition frequency. However, certain load discharge conditions have been found to greatly reduce the lifetimes of expensive laser modulator components and therefore increase the running costs and downtime of the lasers. Describes the use of multiple coupled neural networks which, trained by humans with the required experience, are first able to identify load conditions likely to result in a reduction in the lifetime of the modulator components and then alter the load conditions to minimise the stress placed on the modulator. Dlscontlnuous varlatlonal solutions for the neutron 96106026 diffusion equation Ackroyd, R. T. er al., Ann. Nucl. Energy, Nov. 1996,23, (16), 1289-1300. A maximum variational principle derived by a least squares method is used to obtain discontinuous finite element solution to the neutron diffusion equation. The principle is applied with locally constant and locally linear trial functions to determine a discontinuous finite element solution for a number of one group diffusion problems. The results are in a good agreement with the analytical and the conventional continuous finite element solutions.
The effect of steam separator sfflclency on tran96106027 sient followlng a steam line break Choi, J. H. et al., Ann. Nucf. Energy, Oct. 1996, 23, (15), 1209-1218. Detailed thermalhydraulic simulations for CANDU 6 steam line break inside containment are performed to predict the response of the primary and secondary circuits. The analysis is performed using the thermalhydraulic computer code, CATHENA, with a coupled primary and secondary circuit model. A two-loop representation of the primary and secondary circuits is modelled. The secondary circuit model includes the feedwater line from the deaerator storage tank, multi-node steam generators and the steam line up to the turbine.
Nuclear fuels (scientific, technical)
96lO6031 Fuel designs Nuclear Engineering ht., Sep. 1996, 41, (506), 20-26. A survey of international commercial power-reactor fuel design. Presents updated tables of specifications for all the main fuel types. Presents diaPrams of reactors and desien modifications.
Generation and valldatlon of a new 121 group coupled (n, y) cross section llbrary for fast reactor applications
96106032
Devan, K. et al., Ann. Nucl. Energy, Jul. 1996, 23, (lo), 791-800. A new 121 group (100 neutron group, 21 gamma group) coupled cross section library with anisotro ic scattering has been generated at IGCAR for 25 nuclides by using the 18 85 version of NJOY code system. The basic data used are ENDF/B-IV for neutrons and DLC-99 for photons. A set of six neutron source benchmarks, some gamma source benchmark and one gamma production benchmark has been used in validating this new library. Of these, the first six are computational benchmarks and the last two are experimental benchmarks. Reasonably good predictions have been obtained with this new set relative to the reference solutions. Thus, capability has been developed at IGCAR for generating new multigroup cross section libraries for shielding applications.
Gravltatlonal flooding of a hot solid horizontal surface by water
96106033
Kolev, N. I. Kerntechnik, Aug. 1996, 61, (4), 156-160. Gravitational flooding of a very hot horizontal surface by water results in a two-phase flow with very interesting flow properties. The purpose of this work is to demonstrate some properties of such flows by analysing the properties of the mathematical model describing the flow. With some simplifications the problems can be reduced to a system of three hyperbolic partial differential equations. Eigenvalues, eigenvectors and canonical form are obtained. The criticality condition is obtained from the system describing the steady state. The system of partial differential equations is made dimensionless, and physical scaling criteria are obtained.
High frequency radiation from a moving charged particle In an anlsotroplc hot plasma
96106034
Moser, F. et al., Kernrechnik, Aug. 1996, 61, (4), 183-191. The electromagnetic field components and a general expression for the energy losses caused by polarization of the medium and Cherenkov radiation are determined for a charged particle moving in an anisotropic medium. The energy losses are given for a particle moving in a plasma along an external magnetic field, which is the optical axis. The spectral functions of the total energy loss are calculated numerically, especially for nearly perpendicular propagation, in dependence on the plasma temperature, its anisotropy, the velocity of the moving particle, and the plasma density. An asymptotic expression for the dielectric tensor of an anisotropic hot magnetized plasma is given in a form suitable for numerical calculations.
Experimental lnvestlgatlons of dead-time effect on 96106026 Feynman-alpha method
96106035
Hashimoto, K. Ann. Nucl. Energy, Sep. 1996, 23, (14), 1099-1104. The variance-to-mean measurements were carried out m the ex- and incore experiments to demonstrate the validity and applicability of the improved expression for data analysis, which was derived by considering the dead-time effect of neutron counter. In the ex-core experiment, the validity of the dead-time term, which was added to the conventional expression for the consideration of the dead-time effect, could be confirmed, and the dead time of the counter employed was also determined. In the in-core (Feynam-alpha) experiment, it is confirmed that both the inherent decay constant and the dead time could be obtained by the application of the improved expression to data analysis. The results indicate that the improved expression is available for the data analysis of the Feynam-alpha experiment performed under high-count-rate conditions.
Van Dam, H. Ann. Nucl. Energy, Sep. 1996, 23, (14), 1127-1142. A two-point reactor kinetic model for a strongly reflected reactor is developed and relevant parameters are assessed for the experimental zero-power reactor PROTEUS. The results are described in terms of an extended inhour equation and neutron source transfer functions for the core and the reflector. These transfer functions are applied to analyze reactor response to a pulsed neutron source which can be positioned in the core or in the reflector. The model gives a good description of the so-called kinetic distortion effect which complicates the reactivity determination by pulsed neutron source measurements. Quantitative results are in agreement with experimental data and with correction factors obtained with more detailed space dependent calculations.
Experimental lnvsstl atlons of the separation of aqueous entralnments from M-n-% utyl phosphate by electric fields 96106029
Linardi, M. and Goldacker, H. Kernfechnik, Aug. 1996, 61, (4), 168-172. The effectiveness of static and pulsed electric fields in separating entrainments with radioactive contamination from the PUREX process is investigated. A laboratory-scale electric separator operating on the batch mode was developed for this purpose. The entrainment was labelled with Eu-152. The influences of electric field strength, pulse frequency, mean residence time of the dispersion, and fraction of entrainment are presented.
Exploltlng the plutonium stockplles In PWRs by using Inert matrix fuel
lnhour equation and kinetic distortion in a twopoint reactor klnetlc model
An Integrated signal processing and neural networks system for steam generator tubing diagnostics using eddy current Inspection
96106036
Yan, W. and Upadhyaya, B. R. Ann. Nucl. Energy, Jul. 1996, 23, (lo), 813-825. The primary purpose of this research was to develop an integrated approach by combining information compression methods and artificial neural networks for the monitoring of plant components using nondestructive evaluation data. Specifically, data from eddy current inspection of steam generator tubing was utilized to evaluate this technology. The focus of the research was to develop and test various data compression methods (for eddy current data) and the performance of different neural network paradigms for defect classification and defect parameter estimation.
96106030
Lombardi, C. and Mazzola, A. Ann. Nucl. Energy, Sep. 1996, 23, (14), 1117-1126. The plutonium coming from dismantled warheads and that already stockpiled coming from spent fuel reprocesing have raised many concerns related to proliferation resistance, environmental safety and economy. The option of disposing of plutonium by fission is one of the most widely chscussed and many proposals for plutonium burning in a safe and economical manner have been put forward. Due to their diffusion, PWRs appear to be the main candidates for the reduction of the plutonium stockpiles.
lnvestigatlon of radiations penetration in aluminum used In reactor technology
96106037
El-Sayed Abdo, A. er al., Ann. Nucl. Energy, Jul. 1996,23, (ll), 93.5-945. Measurements have been carried out to determine the spatial and energy distributions of fast neutrons, total gamma rays and secondary gamma rays in aluminum as a reactor wide structural material. Experimental work was performed using one of the horizontal channels of the ET-RR-l reactor. For secondary gamma ray investigations, measurements were carried out for bare, cadmium filtered and boron carbide filtered reactor beams.
Fuel and Energy Abstracts November 1996
427
Concept on coupled spectrum B/l (burnln and/or 96106024 transmutation) reactor for treatment of minor actlnldes % y thermal and fast neutrons Aziz, F. and Kitamoto, A. Ann. Nucl. Energy, Oct. 1996, 23, (15), 1239-1248. A conceptual design of B/T (burning and/or transmutation) reactor based on a modified conventional 1150 MWe-PWR system, with core consisted of two concentric regions for thermal and fast neutrons was proposed herein for Bn treatment of MA (minor actinides).
Control of a copper laser using neural networks 96106026 Buckley, J. M. and Richardson, M. B. Computing & Conrrol Engineering J., Jun. 1996, 7, (3), 145-152. Urenco (Capenhurst) Ltd. has been running high-power copper lasers several years owing to an interest in selective photo-ionisation for commercial enrichment. The main advantages of these lasers as pump sources for this process are their efficiency at high power and their high pulse repetition frequency. However, certain load discharge conditions have been found to greatly reduce the lifetimes of expensive laser modulator components and therefore increase the running costs and downtime of the lasers. Describes the use of multiple coupled neural networks which, trained by humans with the required experience, are first able to identify load conditions likely to result in a reduction in the lifetime of the modulator components and then alter the load conditions to minimise the stress placed on the modulator. Dlscontlnuous varlatlonal solutions for the neutron 96106026 diffusion equation Ackroyd, R. T. er al., Ann. Nucl. Energy, Nov. 1996,23, (16), 1289-1300. A maximum variational principle derived by a least squares method is used to obtain discontinuous finite element solution to the neutron diffusion equation. The principle is applied with locally constant and locally linear trial functions to determine a discontinuous finite element solution for a number of one group diffusion problems. The results are in a good agreement with the analytical and the conventional continuous finite element solutions.
The effect of steam separator sfflclency on tran96106027 sient followlng a steam line break Choi, J. H. et al., Ann. Nucf. Energy, Oct. 1996, 23, (15), 1209-1218. Detailed thermalhydraulic simulations for CANDU 6 steam line break inside containment are performed to predict the response of the primary and secondary circuits. The analysis is performed using the thermalhydraulic computer code, CATHENA, with a coupled primary and secondary circuit model. A two-loop representation of the primary and secondary circuits is modelled. The secondary circuit model includes the feedwater line from the deaerator storage tank, multi-node steam generators and the steam line up to the turbine.
Nuclear fuels (scientific, technical)
96lO6031 Fuel designs Nuclear Engineering ht., Sep. 1996, 41, (506), 20-26. A survey of international commercial power-reactor fuel design. Presents updated tables of specifications for all the main fuel types. Presents diaPrams of reactors and desien modifications.
Generation and valldatlon of a new 121 group coupled (n, y) cross section llbrary for fast reactor applications
96106032
Devan, K. et al., Ann. Nucl. Energy, Jul. 1996, 23, (lo), 791-800. A new 121 group (100 neutron group, 21 gamma group) coupled cross section library with anisotro ic scattering has been generated at IGCAR for 25 nuclides by using the 18 85 version of NJOY code system. The basic data used are ENDF/B-IV for neutrons and DLC-99 for photons. A set of six neutron source benchmarks, some gamma source benchmark and one gamma production benchmark has been used in validating this new library. Of these, the first six are computational benchmarks and the last two are experimental benchmarks. Reasonably good predictions have been obtained with this new set relative to the reference solutions. Thus, capability has been developed at IGCAR for generating new multigroup cross section libraries for shielding applications.
Gravltatlonal flooding of a hot solid horizontal surface by water
96106033
Kolev, N. I. Kerntechnik, Aug. 1996, 61, (4), 156-160. Gravitational flooding of a very hot horizontal surface by water results in a two-phase flow with very interesting flow properties. The purpose of this work is to demonstrate some properties of such flows by analysing the properties of the mathematical model describing the flow. With some simplifications the problems can be reduced to a system of three hyperbolic partial differential equations. Eigenvalues, eigenvectors and canonical form are obtained. The criticality condition is obtained from the system describing the steady state. The system of partial differential equations is made dimensionless, and physical scaling criteria are obtained.
High frequency radiation from a moving charged particle In an anlsotroplc hot plasma
96106034
Moser, F. et al., Kernrechnik, Aug. 1996, 61, (4), 183-191. The electromagnetic field components and a general expression for the energy losses caused by polarization of the medium and Cherenkov radiation are determined for a charged particle moving in an anisotropic medium. The energy losses are given for a particle moving in a plasma along an external magnetic field, which is the optical axis. The spectral functions of the total energy loss are calculated numerically, especially for nearly perpendicular propagation, in dependence on the plasma temperature, its anisotropy, the velocity of the moving particle, and the plasma density. An asymptotic expression for the dielectric tensor of an anisotropic hot magnetized plasma is given in a form suitable for numerical calculations.
Experimental lnvestlgatlons of dead-time effect on 96106026 Feynman-alpha method
96106035
Hashimoto, K. Ann. Nucl. Energy, Sep. 1996, 23, (14), 1099-1104. The variance-to-mean measurements were carried out m the ex- and incore experiments to demonstrate the validity and applicability of the improved expression for data analysis, which was derived by considering the dead-time effect of neutron counter. In the ex-core experiment, the validity of the dead-time term, which was added to the conventional expression for the consideration of the dead-time effect, could be confirmed, and the dead time of the counter employed was also determined. In the in-core (Feynam-alpha) experiment, it is confirmed that both the inherent decay constant and the dead time could be obtained by the application of the improved expression to data analysis. The results indicate that the improved expression is available for the data analysis of the Feynam-alpha experiment performed under high-count-rate conditions.
Van Dam, H. Ann. Nucl. Energy, Sep. 1996, 23, (14), 1127-1142. A two-point reactor kinetic model for a strongly reflected reactor is developed and relevant parameters are assessed for the experimental zero-power reactor PROTEUS. The results are described in terms of an extended inhour equation and neutron source transfer functions for the core and the reflector. These transfer functions are applied to analyze reactor response to a pulsed neutron source which can be positioned in the core or in the reflector. The model gives a good description of the so-called kinetic distortion effect which complicates the reactivity determination by pulsed neutron source measurements. Quantitative results are in agreement with experimental data and with correction factors obtained with more detailed space dependent calculations.
Experimental lnvsstl atlons of the separation of aqueous entralnments from M-n-% utyl phosphate by electric fields 96106029
Linardi, M. and Goldacker, H. Kernfechnik, Aug. 1996, 61, (4), 168-172. The effectiveness of static and pulsed electric fields in separating entrainments with radioactive contamination from the PUREX process is investigated. A laboratory-scale electric separator operating on the batch mode was developed for this purpose. The entrainment was labelled with Eu-152. The influences of electric field strength, pulse frequency, mean residence time of the dispersion, and fraction of entrainment are presented.
Exploltlng the plutonium stockplles In PWRs by using Inert matrix fuel
lnhour equation and kinetic distortion in a twopoint reactor klnetlc model
An Integrated signal processing and neural networks system for steam generator tubing diagnostics using eddy current Inspection
96106036
Yan, W. and Upadhyaya, B. R. Ann. Nucl. Energy, Jul. 1996, 23, (lo), 813-825. The primary purpose of this research was to develop an integrated approach by combining information compression methods and artificial neural networks for the monitoring of plant components using nondestructive evaluation data. Specifically, data from eddy current inspection of steam generator tubing was utilized to evaluate this technology. The focus of the research was to develop and test various data compression methods (for eddy current data) and the performance of different neural network paradigms for defect classification and defect parameter estimation.
96106030
Lombardi, C. and Mazzola, A. Ann. Nucl. Energy, Sep. 1996, 23, (14), 1117-1126. The plutonium coming from dismantled warheads and that already stockpiled coming from spent fuel reprocesing have raised many concerns related to proliferation resistance, environmental safety and economy. The option of disposing of plutonium by fission is one of the most widely chscussed and many proposals for plutonium burning in a safe and economical manner have been put forward. Due to their diffusion, PWRs appear to be the main candidates for the reduction of the plutonium stockpiles.
lnvestigatlon of radiations penetration in aluminum used In reactor technology
96106037
El-Sayed Abdo, A. er al., Ann. Nucl. Energy, Jul. 1996,23, (ll), 93.5-945. Measurements have been carried out to determine the spatial and energy distributions of fast neutrons, total gamma rays and secondary gamma rays in aluminum as a reactor wide structural material. Experimental work was performed using one of the horizontal channels of the ET-RR-l reactor. For secondary gamma ray investigations, measurements were carried out for bare, cadmium filtered and boron carbide filtered reactor beams.
Fuel and Energy Abstracts November 1996
427