DAVILSON GOMES DA SILVA

DAVILSON GOMES DA SILVA

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Human factors evaluation in operators with attention to insider threat detection
2020 - VAZ, ANTONIO C.A.; BORGES, VINICIUS F.; GENEZINI, FREDERICO A.; RODRIGUES, VALDEMIR G.; SILVA, DAVILSON G. da
Analysis and construction of the high density storage racks for spent fuel of the research reactor IEA-R1
2018 - RODRIGUES, ANTONIO C.I.; MADI FILHO, TUFIC; SILVA, DAVILSON G. da
The IEA-R1 research reactor works 40h weekly, with 4.5 Mw power. The storage rack for spent fuel elements has less than half of its initial capacity. Under these conditions, the reactor operating for 32h/week will have 3 spent fuel by year, approximately 3 utilization rate Positions/year; thus, we will have only about six years of capacity for storage. Since the desired service life of the IEA-R1 is at least another 20 years, it will be necessary to increase the storage capacity of spent fuel by doubling the wet storage in the reactor’s pool. 3M’s neutron absorber BoralcanTM was chosen after reviewing the literature about available materials for the construction of a new storage rack. This work presents studies for the construction of new storage racks with double of capacity using the same place of the current ones. Criticality safety analysis was performed with MCNP-5 Monte Carlo code, using two Evaluated Nuclear Data Files (ENDF/B-VI and ENDF/B-VII) in calculations, and subsequently, the results were compared. The full charge of the storage rack with only new fuel elements (maximum reactivity) was considered to calculate the keff. The results obtained in the simulations show that it is possible doubling the storage capacity of the spent fuel elements. Additionally, it complies with safety limits established by International Atomic Energy Agency (IAEA) and Brazilian Commission of Nuclear Energy (CNEN) standards to the criticality criteria (keff <0.95). This is only possible with the use of neutron absorber material.
Analysis and project of the high density storage racks for spent fuel of the research reactor IEA-R1
2018 - RODRIGUES, ANTONIO C.I.; MADI FILHO, TUFIC; SILVA, DAVILSON G. da
The IEA-R1 research reactor works 40h weekly with 4.5 Mw power. The storage rack for spent fuel elements has less than half of its initial capacity. Under these conditions (current conditions of reactor operation 32h weekly will have 3 spend fuel by year, then, approximately 3 utilization rate Positions/year). Thus, we will have only about six years of capacity for storage. Whereas the desired service life of the IEA-R1 is at least another 20 years, it will be necessary to increase the storage capacity of spent fuel. Hence, it is necessary to double the wet storage capacity (storage in the IEA-R1 reactor’s pool). After reviewing the literature about materials available for use in the construction of the new storage rack with absorber of neutrons, the BoralcanTM (manufactured by 3M) was chosen, due to its properties. This work presents studies: (a) for the construction of new storages racks with double of the current capacity using the same place of current storages racks and (b) criticality analysis using the MCNP-5 code. Two American Nuclear Data Libraries were used: ENDF / B-VI and ENDF / B-VII, and the results obtained for each data bases were compared. These analyzes confirm the possibility of doubling the storage capacity of fuel elements burned in the same place occupied by the current storage rack attending to the IEA-R1 reactor needs and attending the safety requirements according to the National Nuclear Energy Commission – CNEN and the International Atomic Energy Agency (IAEA). To calculate the keff new fuel elements (maximum possible reactivity) used in full charge of the storage rack were considered. With the results obtained in the simulation we can conclude that doubling the amount of racks for spent fuel elements are complied with safety limits established in the IAEA standards and CNEN of criticality (keff <0.95). It is mandatory to use neutron absorber material.
Core modeling of the research reactor IEA-R1 with the MCNP-6.2 computational code
2019 - RODRIGUES, ANTONIO C.I.; MADI FILHO, TUFIC; SILVA, DAVILSON G. da
The objective of this work is to develop the modeling of the IEA-R1 reactor core with the MCNP-6.2 computational code that was recently acquired. The main advantage of this new version of the code is the performance of burnup calculations of the fuel elements. This modeling will be valid by comparing the thermal and epithermal neutron flux obtained in the calculations with the MCNP-6.2 and the fluxes measured with the activation of gold foils (Au) with and without cadmium coating (Cd) in the same positions of irradiation and, with the same arrangement of fuel elements in the reactor core. After the validation of this model, the idea is to use it for the burnup calculations of the fuel elements that are fundamental for a correct management of the reactor core. Currently, the management of the core is carried out by deterministic codes that are very old and have many approximations leading to very conservative results, for example, TWODB, HAMMER, and CITATION.
Procedures for manufacturing an instrumented nuclear fuel element
2019 - DURAZZO, M.; UMBEHAUN, P.E.; TORRES, W.M.; SOUZA, J.A.B.; SILVA, D.G.; ANDRADE, D.A.
The IEA-R1 is an open pool research reactor that operated for many years at 2 MW. The reactor uses plate type fuel elements which are formed by assembling eighteen parallel fuel plates. During the years of reactor operation at 2 MW, thermohydraulic safety margins with respect to design limits were always very high. However, more intense oxidation on some external fuel plates was observed when the reactor power was increased to 5 MW. At this new power level, the safety margins are significantly reduced due to the increase of the heat flux on the plates. In order to measure, experimentally, the fuel plate temperature under operation, an instrumented fuel element was constructed to obtain temperature experimental data at various positions of one or more fuel plates in the fuel element. The manufacturing method is characterized by keeping the original fuel element design specifications. Type K stainless sheathed thermocouples are mounted into supports pads in unrestricted positions. During the fuel element assembling, the supports pads with the thermocouples are mechanically fixed by interference between two adjacent fuel plates. The thermocouple wires are directed through the space existing at the bottom of the mounting slot where the fuel plate is fixed to the side plates. The number of thermocouples installed is not restricted and depends only on adaptations that can be made on the mounting slots of the standard fuel element side plates. This work describes the manufacturing procedures for assembling such an instrumented fuel element.
Study and project of the new rack with boron for storage of fuel elements burned in the IEA-R1 research reactor
2017 - RODRIGUES, ANTONIO C.I.; MADI FILHO, TUFIC; SILVA, DAVILSON G. da
The IEA-R1 research reactor works 40h weekly with 4.5 Mw power. The storage rack for spent fuel elements has less than half of its initial capacity. Under these conditions (current conditions of reactor operation 32h weekly will have 3 spend fuel by year, then, approximately 3 utilization rate Positions/year). Thus, we will have only about six years of capacity for storage. Whereas the desired service life of the IEA-R1 is at least another 20 years, it will be necessary to increase the storage capacity of spent fuel. Hence, it is necessary to double the wet storage capacity (storage in the IEA-R1 reactor's pool). After reviewing the literature about materials available for use in the construction of the new storage rack with absorber of neutrons, the BoralcanTM (manufactured by 3TMhis) wwaosr kc hporseesne,n dtsu es ttuod iitess :p r(oap) efrotrie tsh. e construction of new storages racks with double of the current capacity using the same place of current storages racks and (b) criticality analysis using the MCNP-5 code. Two American Nuclear Data Library were used: ENDF / B-VI and ENDF / B-VII, and the results obtained for each data bases were compared. These analyzes confirm the possibility of doubling the storage capacity of fuel elements burned in the same place occupied by the current storage rack attending to the IEA-R1 reactor needs and attending the safety requirements according to the National Nuclear Energy Commission - CNEN and the International Atomic Energy Agency (IAEA). To calculate the keff were considered new fuel elements (maximum possible reactivity) used in full charge of the storage rack. With the results obtained in the simulation we can conclude that doubling the amount of racks for spent fuel elements are complied with safety limits established in the IAEA standards and CNEN of criticality (keff < 0.95).
Método e dispositivo de medição das dimensões do canal de refrigeração em elementos combustíveis tipo placa
2014 - DURAZZO, MICHELANGELO; SILVA, DAVILSON G. da; SANTOS, LAURO R. dos; CARVALHO, ELITA F.U. de; RIELLA, HUMBERTO G.; FONSECA, JULIO C.C.
How the nuclear safety team conducts emergency exercises at the IEA-R1 reactor
2015 - VAZ, ANTONIO C.A.; SILVA, DAVILSON G.; TOYODA, EDUARDO Y.; SANTIA, PAULO S.; CONTI, THADEU N.; SEMMLER, RENATO; CARVALHO, RICARDO N.
Distribuicao de vazao no nucleo do reator de pesquisas IEA-R1
2001 - TORRES, W.M.; UMBEHAUN, P.E.; BAPTISTA FILHO, B.D.; ALMEIDA, J.C.; SOUZA, J.A.B.; SILVA, D.G.
Methodology for GAP measurement in the fuel element fabricated at IPEN
2012 - DURAZZO, M.; SILVA, D.G. da; SANTOS, L.R.; URANO de CARVALHO, E.F.; RIELLA, H.G.