Envíos recientes
Item type: Ítem , Access status: Acceso Abierto , Transport calculations of neutron wave experiments in subcritical assemblies(American Nuclear Society, 1977) Difilippo, Félix C.A recent neutron wave experiment in a thermal-neutron multiplying assembly with and without control rods has been analyzed numerically in terms of transport theory. The code TASK was used for this purpose. The present study dealing with a highly 235U enriched, compact, neutron-multiplicative uranium system indicates that the dispersion law of the assembly is very sensitive to transport effects and to the estimation of the leakage of the fast neutron population. The present calculations of neutron wave propagation in multiplicative systems show that this technique can be used as a highly sophisticated experiment for integral checks of neutrón cross section sets.Item type: Ítem , Access status: Acceso Abierto , Neutron wave propagation in multiplying assemblies with and without control rods(Pergamon Press, 1975) Difilippo, Félix C.In this work the disperssion law is expanded in a power series of the frequency up to the third order; for this, two groups diffusion theory is used. In this manner the nuclear parameters of this approximation can be related with the experimental observables in a closed and definite form. Also a model is developed that predicts the existance of an asymptotic progagation mode even in the presence of control rods; this model permits one to calculate the wave front and the dispersión law. The models are compared with experiments done in a highly compact system with 90 % Z35U enriched uranium fuel and H2O moderator.Item type: Ítem , Access status: Acceso Abierto , The kinetics of a coupled two-core nuclear reactor(American Nuclear Society, 1976) Difilippo, Félix C.; Waldman, Ricardo MarceloA model is developed to investígate the response of a coupled two core reactor to a neutron pulse. Various coupled cores with symmetrical and asymmetrical configurations and compositions are studied. The fundamental spatial mode splits into two distinct decaying submodes. The reactivity of a coupled-core system is.deflned, and two methods are given for its measurement. The model is compared with results of pulsed-neutron experiments performed on a light-water-moderated, coupled, compact two-core reactor fueled with uranium of 90% 235U content and reflected by both light water and graphite in either symmetrical or asymmetrical configurations.Item type: Ítem , Access status: Acceso Abierto , Centrales nucleares: factor de progreso tecnológico nacional(1975) Wortman, Oscar; Quihillalt, Oscar JoséTras el convenio de 1972 en el Consejo Federal de Inversiones y la Comisión Nacional de Energía Atómica, se estudia la posible participación de la industria e ingeniería nacional en los programas de centrales nucleares, evaluando la posiblidad e importgancia de contar con dichas centrales como factor de progreso de la tecnología nacional.Item type: Ítem , Access status: Acceso Abierto , Generator of reactivity functions(Taylor & Francis, 1976) Porto, JoséTime-dependent reactivities of many kinds are use ful for the analysis of neutrón kinetics, such as the study of reactor parameters, neutrón wave propagation, or any other specific evolution of the reactor in the time. This is done by imposing the time function directly on a cadmium rod and measuring the neutron flux. Two experiments were performed: In the first one, the reactivity function required for a sinusoidal output was generated with all its parameters in agreement with the previous calculation. In the second experiment, a parameter was slightly altered. Both cases were analyzed, and their results agreed with calculations based on the point reactor model.