2383 research outputs found
Sort by
Mono or 3D video production for scientific dissemination of nuclear energy applications
No full textThis work presents results of educational videos development, mono or stereo, for scientific dissemination of nuclear energy applications. Nuclear energy span through many important applications for the society, ranging from electrical power generation to nuclear medicine, among others. Thus, the purpose is to disseminate this information for the general public and specially for students. Educational videos consist in a good approach for this purpose, due to the involvement of the public they provide, more than simply text or oral exposition, or even static images presentation. Stereo videos result in even more involvement of the public, besides immersion, the latter due to the realism 3D views provide. The video developed in this work deals with explanations of electrical power generation, including nuclear reactor operation, shows the percentage of nuclear source as power generation, including nuclear reactor operation, shows the percentage of nuclear source as power generation all over the world, and explains also nuclear energy application in medicine. It is expected all these characteristics provided by the use of video or virtual reality techniques will achieve the purpose of disseminating such important information, regarding the benefits of nuclear energy to the society
Modelling the transport of radionuclides released in the Ilha Grande bay (BRAZIL) after a LBLOCA in the primary system of A PWR
Get PDFIt was postulated, in the cooling system of the core, a LOCA, where 431 m³ of soda almost instantaneously was lost. This inventory contained 1.87x1010 Bq/m³ of tritium, 2.22x107 Bq/m³ of cobalt,3.48x108 Bq/m³ of cesium and 3.44x1010 Bq/m³ of iodine and was released in liquid form near the Itaorna cove, Angra dos Reis – RJ. Applying the model in the proposed scenario (Angra 1 and 2 in operation and Angra 3 progressively reducing the capture and discharge after the accident), the simulated dilution of the specific activity of radionuclide spots, reached values much lower than report levels for seawater (1,1x106 Bq/m³, 1,11x104 Bq/m³ and 1,85x103 Bq/m³) after 22 hours, respectively for ³H, 60Co, 131I and 137Cs. From the standpoint of public exposure to radionuclide dispersion, the results of activity concentration obtained by the model suggest that the observed radiological impact is negligible. Based on these findings, we conclude that there would be no radiological impact related to a further release of controlled effluent discharges into Itaorna cove
People detection in nuclear plants by video processing for safety purpose
Get PDFThis work describes the development of a surveillance system for safety purposes in nuclear plants. The final objective is to track people online in videos, in order to estimate the dose received by personnel, during the execution of working tasks in nuclear plants. The estimation will be based on their tracked positions and on dose rate mapping in a real nuclear plant at Instituto de Engenharia Nuclear, Argonauta nuclear research reactor. Cameras have been installed within Argonauta’s room, supplying the data needed. Both video processing and statistical signal processing techniques may be used for detection, segmentation and tracking people in video. This first paper reports people segmentation in video using background subtraction, by two different approaches, namely frame differences, and blind signal separation based on the independent component analysis method. Results are commented, along with perspectives for further work
Framework for virtual control desk projects
No full textThrough the recent advances of the Brazilian nuclear program, the creation of virtual desks allows ergonomic evaluation and thechnique of the same, even before it’s physical implementation, reducing costs and time in addition to allow the virtual training of operators. This project intends to develop a “framework” where the components of a real control desk are available for creating a virtual desk, continuing the project control desk developed at the Laboratório de Interface Homem Sistema do IEN (LABHIS/IEN). Through the C++ programming language integrated with the OPENGL graphics librabry was possible to create the desk and it’s components, allowing a graphical modeling in 3D (stereo) of a virtual control desk where the operator, with the and of GLUI user interface library, can choose what and where the components are positioned on the bench, and select the type of desk wanted from the pre-defined templates. Finally, with the control desk mounted and configured, enabling a virtual interaction with operators, making possible to reproduce it’s functionalities
Control room design of a nuclear reactor used to produce radioisotope
Get PDFA control room is defined as a functional entity with an associated physical structure, where the operators carry
out the centralized control, monitoring and administrative responsibilities. Inadequate integration between
control room and operators reduces safety, increases the operation complexity, complicates operator training and increases the likelihood of human errors occurrence. The purpose of this paper is to present a specific approach for the design of the main control room of a nuclear reactor used to produce radioisotope. The approach is based on human factors standards and the participation of a multidisciplinary team in the conceptual and basic phases of the design. Using the information gathered from standards and from the multidisciplinary an initial sketch 3D of the main control room is being developed
Assesment of a shielding for a portable thyroid uptake system using Monte Carlo Simulation
Get PDFThe recent advances and improvements on nuclear medicine area involving diagnostic and therapy tests has
called attention of electronic engineers on how to design modern detection probes. The basic modern design
targets are related to the size and weight (smaller) and, mainly, to higher detection efficiency. We have built in
the past a probe that has been used for diagnostic thyroid exams since 2004 in the Nuclear Medicine Service
(NMS) of Universidade Federal do Rio de Janeiro (UFRJ) hospital. However, its design has been made
considering that it would be installed and operated just in typical exam rooms of NMS of any hospital. In order
to the equipment be easily used in smaller operational rooms, like intensive therapy units (ITU) or hospital
rooms, the probe should be light enough and consequently be handled without cause any discomfort to the
patient. This goal could be reached by developing a new probe, which has a shielding, and collimator properly
designed for this purpose. The aim has been to achieve the better ratio between interest measurement radiation and background radiation with good detection efficiency for a specific geometry. This work will present a source-detection computational simulation considering different compound shielding materials. The simulation will be performed using MCNPX general code considering radiation energy sources most used in thyroid tests
Uma formulação de elementos finitos estabilizada de segunda-ordem no tempo para escoamentos viscosos com transferência de calor
No full textCom os problemas de aquecimento global e a busca por fontes energéticas limpas, o aumento do emprego de energia nuclear é esperado. Assim, o desenvolvimento de tecnologias e estudos científicos para o uso de usinas nucleares é imprescindível, em particular na área de engenharia de reatores. No desenvolvimento de reatores nucleares, a mecânica de fluidos e a transferência de calor assumem papel de destaque. A fluidodinâmica computacional computacional, conhecida como CFD a partir da sigla em Inglês para Computational Fluid Dynamics, é cada vez mais utilizada para otimizar os custos e a segurança dos projetos. Esta dissertação apresenta um método estabilizado de elementos finitos de segunda ordem para a solução de problemas de mecânica de fluidos e transferência de calor. A discretização com segunda ordem no tempo precede a discretização espacial com elementos finitos. Os termos de estabilização surgem naturalmente do processo de discretização, ao invés de serem introduzidos a priori na formulação variacional. O método foi implementado no programa ´ns_new_solver_2d_a_v2_MPI´, escrito em FORTRAN90, desenvolvido no Laboratório de Computação Paralela do Instituto de Engenharia Nuclear (LCP/IEN). Soluções numéricas de alguns exemplos representativos, envolvendo convecção natural, mista e forçada, demonstram que a formulação estabilizada proposta neste trabalho apresenta excelente concordância com resultados experimentais e computacionais disponíveis na literatura
A second-order time accurate finite element formulation for quasi-incompressible viscous flow and heat transfer stabilized by local time-steps
No full textA stabilized finite element method for the solution of viscous flow and heat transfer is presented. An equation
for pressure is derived from a second-order time accurate Taylor-Galerkin procedure that combines the mass and the
momentum conservation laws. At each time-step, once the pressure has been determined, the velocity field and the
temperature field are computed solving discretized equations obtained from another second-order time accurate
scheme and a least-squares minimization of momentum and energy residual. Thus, the procedure leads to a stabilized
finite element method suitable for the simulation of heat transfer problems in free, mixed and forced convection. The
terms that stabilize the finite element method arise naturally from the process, rather than being introduced a priori in
the variational formulation. Local time-steps, chosen according to the time-scales of convection-difusion of momentum
and energy, play the role of stabilization parameters. Numerical solutions of some representative examples
demonstrate the application of the proposed stabilized formulation, where good agreement with previously published
experimental and computational results have been obtained.A stabilized finite element method for the solution of viscous flow and heat transfer is presented. An equation
for pressure is derived from a second-order time accurate Taylor-Galerkin procedure that combines the mass and the
momentum conservation laws. At each time-step, once the pressure has been determined, the velocity field and the
temperature field are computed solving discretized equations obtained from another second-order time accurate
scheme and a least-squares minimization of momentum and energy residual. Thus, the procedure leads to a stabilized
finite element method suitable for the simulation of heat transfer problems in free, mixed and forced convection. The
terms that stabilize the finite element method arise naturally from the process, rather than being introduced a priori in
the variational formulation. Local time-steps, chosen according to the time-scales of convection-difusion of momentum
and energy, play the role of stabilization parameters. Numerical solutions of some representative examples
demonstrate the application of the proposed stabilized formulation, where good agreement with previously published
experimental and computational results have been obtained
Automatic defect identification on PWR nuclear power station fuel pellets
No full textThis article presents a new automatic identification technique of structural failures in nuclear green fuel
pellet. This technique was developed to identify failures occurred during the fabrication process. It is
based on a smart image analysis technique for automatic identification of the failures on uranium oxide
pellets used as fuel in PWR nuclear power stations. In order to achieve this goal, an artificial neural network
(ANN) has been trained and validated from image histograms of pellets containing examples not only from
normal pellets (flawless), but from defective pellets as well (with the main flaws normally found during
the manufacturing process). Based on this technique, a new automatic identification system of flaws
on nuclear fuel element pellets, composed by the association of image pre-processing and intelligent,
will be developed and implemented on the Brazilian nuclear fuel production industry. Based on the
theoretical performance of the technology proposed and presented in this article, it is believed that this
new system, NuFAS (Nuclear Fuel Pellets Failures Automatic Identification Neural System) will be able to
identify structural failures in nuclear fuel pellets with virtually zero error margins. After implemented,
the NuFAS will add value to control quality process of the national production of the nuclear fuel