GAIANE SABUNDJIAN

Resumo

Possui graduação em Bacharel e Licenciatura Em Física pela Pontifícia Universidade Católica de São Paulo(1978), mestrado em Tecnologia Nuclear / Reatores de Potência pelo Instituto de Pesquisas Energéticas e Nucleares(1981) e doutorado em Engenharia Mecânica pela Escola Politêcnica de São Paulo(1999). Atualmente é TECNOLOGISTA SENIOR do Comissão Nacional de Energia Nuclear. Tem experiência na área de Engenharia Nuclear, com ênfase em Tecnologia dos Reatores. Atuando principalmente nos seguintes temas:Elementos Finitos, Formulação Petrov-Galerkin, Equações de Navier-Stokes, Fluidos Incompressíveis, Funções de Expansão Hierárquicas. (Texto extraído do Currículo Lattes em 13 out. 2021)

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Agora exibindo 1 - 10 de 42
  • Artigo IPEN-doc 28268
    RELAP5 code simulation of the Angra2 pressurizer surge line accident
    2021 - SABUNDJIAN, GAIANE; PACHECO, RAFAEL R.; CONTI, THADEU das N.; LIMA, ANA C. de S.; SANCHES, ANDREA
  • Artigo IPEN-doc 27242
    Análise do acidente de perda de refrigerante primário devido a quebra da linha de surto do pressurizador da usina nuclear Angra 2
    2020 - BORGES, EDUARDO M.; CONTI, THADEU das N.; SANCHES, ANDREA; SABUNDJIAN, GAIANE
    O objetivo deste trabalho foi simular e avaliar com o código RELAP5 o acidente base de projeto de perda de refrigerante primário devido a uma ruptura média na linha de surto do pressurizador da usina nuclear Angra 2. Este acidente foi uma quebra do tipo guilhotina ou seja 100% na linha de surto do pressurizador, que representa uma ruptura de 437 cm². Nesta análise, verificou-se que as lógicas de atuação do Sistema de Proteção do Reator (SPR) e do Sistema de Resfriamento de Emergência do Núcleo (SREN) de Angra 2, utilizadas nesta simulação, funcionaram corretamente, mantendo a integridade do núcleo com as temperaturas do núcleo em níveis aceitáveis durante todo o evento. Os resultados obtidos foram satisfatórios, quando comparados com os apresentados no Relatório Final de Análise de Segurança de Angra 2 (FSAR/A2).
  • Artigo IPEN-doc 27183
    Total and partial loss of coolant experiments in an instrumented fuel assembly of IEA-R1 research reactor
    2020 - MAPRELIAN, EDUARDO; TORRES, WALMIR M.; BELCHIOR JUNIOR, ANTONIO; UMBEHAUN, PEDRO E.; BERRETTA, JOSE R.; SABUNDJIAN, GAIANE
    The safety of nuclear facilities has been a growing global concern, mainly after the Fukushima nuclear accident. Studies on nuclear research reactor accidents such as the Loss of Coolant Accident (LOCA), many times considered a design basis accident, are important for ensure the integrity of the plant. A LOCA may lead to the partial or complete uncovering of the fuel assemblies and it is necessary to assure the decay heat removal as a safety condition. This work aimed to perform, in a safe way, partial and complete uncovering experiments for an Instrumented Fuel Assembly (IFA), in order to measure and compare the actual fuel temperatures behavior for LOCA in similar conditions to research reactors. A test section for experimental simulation of Loss of Coolant Accident named STAR was designed and built. The IFA was irradiated in the IEA-R1 core and positioned in the STAR, which was totally immersed in the reactor pool. Thermocouples were installed in the IFA to measure the clad and fluid temperatures in several axial and radial positions. Experiments were carried out for five levels of uncovering of IFA, being one complete uncovering and four partial uncovering, in two different conditions of decay heat. It was observed that the cases of complete uncovering of the IFA were the most critical ones, that is, those cases presented higher clad temperatures when compared with partial uncovering cases, for the specific conditions of heat decay intensity and dissipation analyzed. The maximum temperatures reached in all experiments were quite below the fuel blister temperature, which is around 500 °C. The STAR has proven to be a safe and reliable experimental apparatus for conducting loss of coolant experiments.
  • Artigo IPEN-doc 26388
    Analysis of the protective actions in the Emergency Planning Zones (EPZs) in the Angra dos Reis region through the calculation of the dose for public individuals due to a severe accident at the Angra 2 Nuclear Plant
    2019 - AGUIAR, ANDRE S.; LEE, SEUNG M.; SABUNDJIAN, G.
    This work presents the results of the computational simulations of the consequences of a severe accident in Angra 2 nuclear power plant. The severe accident was supposed to be caused by a rupture of 380cm2 in the primary reactor coolant system resulting in loss of coolant. Since the area of the rupture is quite smaller than the total flow area of the pipe of the primary coolant system, 4418cm2, the accident is classified as a small break loss of coolant accident. However, this rupture by itself would not bring the system about a severe accident, which must involve a considerable damage in the nuclear core. Thus, some boundary conditions were added to the problem in order to set a scenario of this kind of accident, which was simulated by means of the MELCOR code. The results obtained by this code show that the release of the radionuclide to the environment starts at the opening of the containment relief valve, and this valve, in turn, opens when the containment pressure reaches 7bar, at 168 hours after the break of the pipe of the coolant system, according to the simulation. The program used for calculation of the release of the radionuclides to the surrounding region of the nuclear plant was the CALMET/CALPUFF code, so that the atmospheric and transport model were elaborated for this code. A source term was used in order to carry out an analysis of the protective actions in the emergency planning zones by means dose calculation for individuals of the public, and it was based on two different scenarios: first scenario, release of the total activity to the atmosphere of Xe, Cs, Ba and Te, after 2h simulation and second scenario, release of the total activity to the atmosphere of Xe, Cs, Ba and Te, after 168h of simulation.
  • Artigo IPEN-doc 26373
    MELCOR simulation of a severe accident scenario derived from a small break loca in a typical PWR with passive autocatalytic recombiners
    2019 - LEE, SEUNG M.; LAPA, NELBIA S.; SABUNDJIAN, GAIANE
    This work presents the simulation of a severe accident scenario in a referential model of pressurized water reactor, which came about from a rupture of 20cm2 in a cold leg of a reactor cooling system. The simulation was carried out on the MELCOR code using a model elaborated by the Global Research for Safety – Germany, with the passive autocatalytic recombiners implemented in almost every compartment in the containment. The efficacy and effectiveness of this well-known mitigating measure of severe accident management are demonstrated by means of a comparison with the case previously simulated without this measure using the same model. This referential reactor is important and very useful for the independent analysis of severe accidents in the Brazilian Angra 2 nuclear power plant in virtue of the similarity between both of them, so that after some proper modifications on this referential reactor’s model, it could be applied for the study of severe accidents in the other. In this sense, the result presented in this work is to be taken as an important reference for the severe accident analysis of Angra 2.
  • Artigo IPEN-doc 25067
    Simulação de um SBLOCA em Angra 2 com o RELAP5
    2018 - BORGES, EDUARDO M.; SABUNDJIAN, GAIANE; CONTI, THADEU das N.; BRAZ FILHO, FRANCISCO A.; GUIMARAES, LAMARTINE N.F.
    O objetivo deste trabalho foi simular e avaliar o acidente básico de projeto de perda de refrigerante por pequena ruptura de 50 cm2 na perna fria do circuito primário da usina nuclear Angra 2. Nesta simulação, verificou-se que as lógicas de atuação do Sistema de Proteção do Reator (SPR) e do Sistema de Resfriamento de Emergência do Núcleo (SREN) de Angra 2 utilizadas nesta simulação funcionaram corretamente, mantendo a integridade do núcleo com temperaturas aceitáveis durante todo o evento. Os resultados obtidos foram satisfatórios quando comparados com os apresentados pelo Relatório Final de Análise de Segurança de Angra 2 (FSAR/A2).
  • Artigo IPEN-doc 24026
    Identification of flow regimes and heat transfer modes in ANGRA2 core during the simulation of the small break loss of coolant accident of 250 cm2 in the cold leg of primary loop using RELAP5 code
    2017 - BORGES, EDUARDO M.; SABUNDJIAN, GAIANE
    The aim of this paper is to identify the flow regimes, the heat transfer modes, and the correlations used by RELAP5/MOD3.2.gama code in ANGRA 2 during the Small-Break Loss-of-Coolant Accident (SBLOCA) with a 250cm2 of rupture area in the cold leg of primary loop. The Chapter 15 of the Final Safety Analysis Report of ANGRA 2 (FSAR-A2) reports this specific kind of accident. The results from this work demonstrated the several flow regimes and heat transfer modes that can be present in the core of ANGRA 2 during the postulated accident. The results obtained for Angra2 nuclear reactor core during the postulated accident were satisfactory when compared with the FSAR-A2. Additionally, the results showed the correct actuation of the ECCS guaranteeing the integrity of the reactor core.
  • Artigo IPEN-doc 24022
    PCRELAP5 - a visual graphic preprocessor for RELAP5
    2017 - MONACO, DANIEL F.; SABUNDJIAN, GAIANE
    The aim of this work is to develop PCRELAP5, a visual preprocessor for RELAP5, reducing time, effort and maintenance costs spent in new projects for RELAP5. This preprocessor allows user to draw new nuclear power plant nodalization in a completely interactive way, and input parameters for each node in a more user-friendly experience. Once parameters are changed on screen, the input cards of RELAP5 code are changed in real time. RELAP5 users will have a tool to reduce time and effort for new studies and existing projects. Therefore, this project proposes to significantly leverage studies related to nuclear accident analysis, making the RELAP5 code more user-friendly. In order to demonstrate this preprocessor capability, the CANON experiment will be used as an example. The PCRELAP5 preprocessor is being developed using Microsoft® Visual Studio® as a Microsoft® Excel® add-in, due to the low cost of distribution and maintenance, and also allowing new RELAP5 projects be leveraged by the MS Excel® flexibility.
  • Artigo IPEN-doc 23030
    Simulação do acidente de perda de refrigerante na linha do sistema de resfriamento de emergência do núcleo conectada à perna fria do circuito primário de ANGRA 2
    2016 - BORGES, EDUARDO M.; CONTI, THADEU das N.; SABUNDJIAN, GAIANE
    Devido a ocorrência de acidentes nucleares, organizações reguladoras nucleares mundiais incluiram a análise de acidentes considerados como acidentes base de projeto – Perda de Refrigerane Primario grande ou pequenas-rupturas (Losso of Coolant Accident - LOCA) e incluí-los nos relatórios de análise de segurança de instalações nucleares. No Brasil, a ferramenta selecionada pela autoridade de licenciamento, Comissão Nacional de Energia Nuclear (CNEN), é a o código RELAP5. Este trabalho tem por objetivos simular e avaliar o acidente postulado de perda de refrigerante na linha do Sistema de Resfriamento de Emergência do Núcleo, que está conectada à perna fria do circuito primário da usina nuclear ANGRA 2. A área da ruptura é de 380 cm2 que é considerado um acidente de perda de refrigerante por pequena ruptura, conhecido como Small Break Loss of Coolant Accident (SBLOCA), que é descrito no Capítulo 15 do Relatório de Final de Análise de Segurança de ANGRA 2 – RFAS/A2. A metodologia utilizada para para atingir os objetivos deste trabalho é a simulação do acidente proposto com o código RELAP5, que é um programa com filosofia best estimate. As condições iniciais e de contorno adotadas na simulação são as mesmas mencionadas no RFAS/A2 e que são descritas no trabalho. Os resultados obtidos mostraram que o Sistema de Proteção do Reator e o Sistema de Resfriamento de Emergência do Núcleo de ANGRA 2 atuaram corretamente durante o evento simulado, mantendo a integridade do núcleo com temperaturas bem abaixo do valor limite (1200°C). Os resultados obtidos durante o acidente podem ser considerados satisfatórios, quando comparados aos dados apresentados no Relatório de Final de Análise de Segurança de ANGRA 2.