FERNANDO DE CASTRO JUNQUEIRA
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Artigo IPEN-doc 30633 Assessing shielding thickness in Am-241 nuclear battery2024 - 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 29832 A new 124Xe irradiation system for 123I production2023 - COSTA, OSVALDO L. da; BARCELLOS, HENRIQUE; MATSUDA, HYLTON; SUMIYA, LUIZ C. do A.; JUNQUEIRA, FERNANDO de C.; MATSUDA, MARGARETH M.N.; LAPOLLI, ANDRE L.Since 2001, Nuclear and Energy Research Institute IPEN-CNEN has produced weekly ultrapure iodine-123, using a manual irradiation system, fully developed in IPEN. Iodine-123 radiopharmaceuticals have been produced and distributed to hospitals and clinics of nuclear medicine, where several diagnostic imaging procedures for thyroid, brain and cardiovascular functions are performed. Due to the short half-life and emission of low-energy photons, this radioisotope becomes suitable for diagnosis in children. In the present work, the technical and constructive aspects of a new fully automated irradiation system, dedicated to 123I routine production, employing enriched xenon-124 gas as the target material is presented. This new system consists of a target, a water and helium cooling system, a cryogenic system, an electric power system, and a control and process monitoring unit, composed of supervisory software, connected to a programmable logic controller via personal computer. In this new concept, there is no need for human intervention during radioisotope production, reducing the possibility of eventual failures or incidents involving radioactive material. By using this new system, a specific yield of 2.70 mCi/μAh per irradiation was achieved in validation runs, and after three years of routine production of iodine- 123, the system showed reliability and resilience.Artigo IPEN-doc 29113 Design and assembly of an XY-type beam current monitor for cyclotron accelerators2023 - BARCELLOS, HENRIQUE; MATSUDA, HYLTON; LAPOLLI, ANDRE L.; SUMIYA, LUIZ C. do A.; JUNQUEIRA, FERNANDO de C.; COSTA, OSVALDO L. daA water-cooled XY-type beam current monitor was designed, manufactured and assembled in a cyclotron accelerator beam transport line. Tests were performed, demonstrating that apparatus is an instrument of great assistance in proton beam position. The XY-type beam current monitor has been widely used in liquid target irradiations, employing irradiation system which were originally designed for irradiations on 18 MeV cyclotron accelerator (Cyclone 18, IBA) only, however, with this apparatus, the target may be exchanged between the 30 MeV (Cyclone 30, IBA) and 18 MeV cyclotrons.Artigo IPEN-doc 27616 The RMB project2020 - 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 reactor2020 - 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 project2020 - 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.