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Agora exibindo 1 - 7 de 7
  • Artigo IPEN-doc 30633
    Assessing shielding thickness in Am-241 nuclear battery
    2024 - ANTUNES, P.C.G.; SOUZA, C.D. de; SHORTO, J.M.B.; BELCHIOR JUNIOR, A.; JUNQUEIRA, F.C.; ZEITUNI, C.A.; CABRAL, E.L.L.; RIBEIRO, M.A.M.
  • Artigo IPEN-doc 27616
    The RMB project
    2020 - PERROTTA, J.A.; CARVALHO, E.F.U.; DURAZZO, M.; SANTOS, L.R. dos; BAPTISTA, J.A.; SILVA, J.E.R. da; JUNQUEIRA, F.C.; SANTOS, ADIMIR dos; ARAUJO, A.M.V. de; TOMAZELLI, I.
    The Brazilian Nuclear Energy Commission (CNEN) decided to construct a new research reactor, named RMB (Brazilian Multipurpose Reactor). It is a 30 MW open pool-type research reactor using low enriched uranium fuel, and several associated facilities and laboratories. To establish an infrastructure for producing fuel assemblies for RMB operation and uranium targets for Mo-99 production, the RMB technical secretary has developed a coordinated project for the fuel cycle management system, putting together the fuel technology actors in Brazil. The goals of this coordinated project were: (i) to have a centrifuge cascade enriching uranium up to 20 wt% with the capacity to supply RMB yearly needs; (ii) to upgraded the CNEN existing infrastructure to produce nuclear fuel assemblies and uranium targets for the RMB yearly needs; (iii) to produce a set of fuel assemblies for a real RMB mockup core at the IPEN/MB-01 Critical Facility of CNEN. The RMB project design incorporates structures, systems and components (SSC) for interim storage of spent fuels for the hole plant lifetime. This paper presents details of the coordinated project that gives support and sustainability to the RMB fuel cycle supply and the spent fuel SSC designed.
  • Artigo IPEN-doc 26900
    Analytical and experimental analysis on safety related aspects of the RMB research reactor
    2020 - BELCHIOR JUNIOR, A.; SANTOS, A.A.C. dos; FREITAS, R.L.; SOARES, H.V.; JUNQUEIRA, F.C.; MANTECON, J.G.; MATTAR NETO, M.; MENZEL, S.C.; TORRES, W.M.; UMBEHAUN, P.E.
    This paper presents some numerical and experimental safety related activities developed at the Brazilian Multipurpose Reactor (RMB) project by CNEN research institutes. Brief comments on the models and results are presented with emphasis to their relation to the safe design and operation of the reactor. Thermal-hydraulic analysis for Siphon Breaker of the Core Cooling System (CCS); pools hot water layer; core chimney of CCS and spent fuel transport cask are presented, showing results, advantages, difficulties and drawbacks for each analyzed case. All are very distinct cases, involving phenomena that range from two-phase flow and thermal-stratification to lead melting. Beside the one-dimensional thermal hydraulic system Code RELAP5, Computational Fluid Dynamics (CFD) is shown to play an important role in the analysis being performed as it can detail the flow and temperature fields of complex components and phenomena, which are extremely difficult to model analytically or experimentally. Two experimental circuits designed to test RMB fuel elements performance are also presented.
  • Artigo IPEN-doc 26783
    New plate-type core of the IPEN/MB-01 research reactor facility for validation of RMB project
    2020 - SANTOS, ADIMIR dos; YAMAGUCHI, MITSUO; FANARO, LEDA C.C.B.; SANTOS, DIOGO F. dos; SOUZA, GREGORIO S. de; JUNQUEIRA, FERNANDO de C.; SILVA, GRACIETE S. de A. e; BELCHIOR JUNIOR, ANTONIO; PRADO, ADELK de C.; JOAO, THIAGO G.; ROSSI, PEDRO C.R.
    The IPEN/MB-01 research reactor had its first criticality in November 1988 and, ever since, has been of major importance in Brazilian reactor physics researches, achieving international level for experiments comparison and validation (benchmarks). In this facility it is possible to build many different core configurations (i.e., rectangular, square and cylindrical), once versatility and flexibility were both taken into account on its initial project. The core is a fissile material assembly, inserted in a water tank, where the chain reaction is self-maintained and controlled at low power levels, so that, in normal operation, the feedback effects of temperatures are negligible. The core is intended for neutrons simulation of light water moderated reactors allowing the experimental verification of the calculation methods, reactor cell and mesh structures, control rods effectiveness, isothermal reactivity coefficients and core dynamics due to reactivity insertions. The first standard IPEN/MB-01 core had UO2 rod-type fuel, 4.3 % enriched in U-235 and using B4C and Ag-In-Cd rods for safety and control of the reactor. The facility is located at IPEN/CNEN-SP (Nuclear and Energy Research Institute), in Sao Paulo - Brazil. Within the scope of the new research reactor project, the Brazilian Multipurpose Reactor (RMB), it was designed a new critical configuration for the IPEN/MB-01. After thirty years of work, the rod-type fuels were replaced by plate-type fuels, in order to validate the RMB calculation methodologies, as well as the nuclear data libraries used. The RMB is an open pool-type reactor with maximum power of 30 MW, being the core a 5x5 configuration, consisting of 23 fuel elements, made of U3Si2-Al, having a medium density of 3.7 gU/cm3 and 19.75% enriched in U-235, and two positions available in the core for materials irradiation devices. The production of radioisotopes, silicon doping, neutron activation analysis, nuclear fuels and structural materials testing and the development of scientific and technological research using neutron beams are the main targets of the RMB enterprise. The new IPEN/MB-01 core has a 4×5 configuration, having 19 fuel elements, consisting of U3Si2-Al, 2.8 gU/cm³ and 19.75% enriched in U-235, plus one aluminum block. The IPEN/MB-01 new plate-type fuel assembly uses Cadmium wires as burnable poison, as the one used in RMB core for controlling the core power density and excess of reactivity during its operation. The core is also reflected by 4 boxes of heavy water (D2O), inserted in a moderator tank of light water. The maximum nominal power is 100 W and, for a safe operation, the critical assembly has both safety and auxiliaries’ systems. This paper presents a description of the new core and the principal neutronic parameters. The new core of the IPEN/MB-01 will be certainly a world class benchmark core for the core physics calculation of research reactors.
  • Artigo IPEN-doc 26370
    Structural integrity analysis of the heavy water reflector tanks of the IPEN/MB-01 Reactor
    2019 - FAINER, GERSON; FALOPPA, ALTAIR A.; OLIVEIRA, CARLOS A. de; JUNQUEIRA, FERNANDO C.; FIGUEIREDO, CAROLINA D.R.; SANTOS, MARCELO M. dos; CARVALHO, DANIEL S.M.; MATTAR NETO, MIGUEL
    The IPEN/MB-01 is a zero power research reactor designed and built by IPEN in partnership with the Brazilian Navy. This reactor is located in IPEN and began operating in 1988. IPEN/MB-01 has been used as an experimental facility for studies on neutron parameters of nuclear reactors moderated by light water. In 2016, a project to modify the core structure of IPEN/MB-01 Reactor was initiated. This project aims the replacement of the rod-type fuel structure for a plate-type one. In order to optimize the performance of the experiments, four tanks filled with D2O were installed around the core. This new core will contain fuel elements that are similar to the ones that will be used in the Brazilian Multipurpose Reactor. In this paper, a complete structural integrity analysis of the four heavy water reflector tanks installed in IPEN/MB-01 Reactor is presented. A numerical analysis was performed applying the finite element method, using ANSYS software and considering ASME Code VIII, division 2.
  • Artigo IPEN-doc 24129
    A new 124Xe irradiation system for 123I routine production at the 30 MeV IPEN-CNEN/SP cyclotron
    2017 - LAPOLLI, ANDRE L.; BARCELLOS, HENRIQUE; MATSUDA, HYLTON; SUMIYA, LUIZ C. do A.; JUNQUEIRA, FERNANDO de C.
    Since 2001 the Nuclear and Energy Research Institute (IPEN/CNEN-SP, Brazil) has produced about 2.5 mCi/mAh of 123I weekly using a manual irradiation system fully developed by its researchers. Ultrapure 123I has been produced and distributed to hospitals and clinics where several diagnostic imaging procedures are done for thyroid, brain and cardiovascular functions. Due to the short half-life and emission of low-energy photons, this radioisotope becomes suitable for diagnosis in children. Currently IPEN researchers are involved in the development of a new fully automated irradiation system dedicated to 123I routine production employing enriched xenon gas (124Xe) as the target material. This new system consists of a target port, a water and a helium cooling system, a cryogenic system, an electric power system, a control and process monitoring unit composed of a supervisory software connected to a Programmable Logic Controller (PLC) via personal computer. In this new concept, there is no need for human interference during radioisotope production, reducing the possibility of eventual failures or incidents involving radioactive material. In this way, with this new system, a specific yield of approximately 3.5 mCi/mAh per irradiation is expected and this will meet a large part of the national demand for this important radioisotope. In the present work will be presented all the technical and constructive aspects of this new system as well as the results obtained in the irradiation of tests.
  • Artigo IPEN-doc 24094
    A simple and powerful XY-type current monitor for 30 MeV IPEN/CNEN-SP cyclotron
    2017 - BARCELLOS, HENRIQUE; MATSUDA, HYLTON; SUMIYA, LUIZ C. do A.; JUNQUEIRA, FERNANDO de C.; COSTA, OSVALDO L. da
    A water-cooled XY-type current monitor was designed and built in the Cyclotrons Laboratory of the Nuclear and Energy Research Institute (IPEN). It is a very simple design and easily adaptable to the cyclotron beam lines. Tests were done demonstrating to be an instrument of great assistance in proton beam position along beam transport line and target port. Nowadays the XY-type current monitor has been widely used in 18F-FDG routine productions, employing irradiation system which were originally designed for productions on 18 MeV cyclotron accelerator only, however, applying the XY-type current monitor the target port may be exchanged between the 30 MeV and 18 MeV cyclotrons and the observed results are in perfect agreement with expected.