ADIMIR DOS SANTOS

ADIMIR DOS SANTOS

(Fonte: Lattes)

ORCID

ScopusID

ResearcherID

Resumo

Possui graduação em Bacharelado Em Física pela Universidade de São Paulo (1975), mestrado em Reatores Nucleares de Potência e Tecnologia do Com pelo Instituto de Pesquisas Energéticas e Nucleares (1978) e doutorado em Nuclear Engineering pela University of Wisconsin – Madison (1984). Atualmente é PESQUISADOR TITULAR III do Instituto de Pesquisas Energéticas e Nucleares, professor titular da Universidade de São Paulo e Revisor de periódico da Progress in Nuclear Energy. Tem experiência na área de Engenharia Nuclear, com ênfase em Tecnologia dos Reatores. Atuando principalmente nos seguintes temas: SENSITIVITY ANALYSIS, TRANSMUTATION, THORIUM, U-233 BREEDING. (Texto extraído do Currículo Lattes em 28 set. 2021)

Página do item completo

Resultados de Busca

Agora exibindo 1 - 10 de 15

IPEN/MB-01 reactor experiments with nickel reflectors
2019 - SILVA, GRACIETE S. de A. e; MURA, LUIS F.L.; FUGA, RINALDO; SANTOS, ADIMIR dos
In the validation and verification processes of calculation methodologies and associated nuclear data libraries, the existence of experiments that can be considered benchmarks is of fundamental importance. For this purpose, a set of experiments with heavy material nuclear reflector was performed in the IPEN/MB-01 reactor using nickel plates properly inserted in the west face of the reactor core. A total of 32 plates around 3 mm thick were used in the experiment. The axial width and length were sufficient to cover the entire active reactor core. For each plate placement step, reactivity measurements were made due to their insertion in the core; as well as of the critical position of the equally removed BC1 and BC2 control rods. It could be observed that the increase of neutron absorption and consequent decrease of neutron moderation dominated the whole physics of the problem when few plates of reflective material were inserted (about 3 plates). Thereafter, neutron reflection became important overcoming neutron absorption; the reactivity increased until it surpassed the situation without plate (excess reactivity zero) obtaining an increase (net gain) of reactivity with the 32 plates inserted (about 295 pcm). Therefore, it was observed that the reflected nucleus became more reactive than the nucleus without reflective material. The theoretical analysis using MCNP-5 and ENDF/B-VII.0 nuclear data library showed the physical aspects of neutron absorption and reflection in the heavy reflector considered; however, it presented a discrepancy when fast neutron reflection dominates the physical phenomenon of neutron transport. In order to verify the impact of other models of thermal scattering of hydrogen in water for the computational simulations of the experiments, three models were considered, besides the one used by the ENDF/B-VII.0 library: ENDF/B-VII.0 scattering law; new evaluation of the S (alpha, beta) for hydrogen bound in water performed in Bariloche Atomic Center, Argentina; and the calculated with new released evaluations for (235)U, (238)U and (16)O.
Monte Carlo modeling of the new plate-type core for the Brazilian IPEN/MB-01 research reactor
2019 - JOÃO, THIAGO G.; SANTOS, DIOGO F. dos; ROSSI, PEDRO C.R.; SOUZA, GREGORIO S. de; SANTOS, ADIMIR dos
After 30 years of operation, the IPEN/MB-01 research reactor is about to receive a new plate-type core. This replacement is due to the Brazilian Multipurpose Reactor (RMB) needs, the largest project in nuclear engineering taking place in Brazil. The RMB will be a 30MW open pool-type research reactor, keeping the core in a 5x5 configuration (23 fuel elements, made of U3Si2-Al fuel plates, with 3.7 gU/cm3, 19.75% enriched in U-235 and two extra positions available for materials irradiation). The radioisotopes production, material irradiation, nuclear fuels structural testing and the development of scientific and technological research using neutron beams are the main targets of the RMB enterprise. In this way, in order to verify, experimentally, the calculation methods and data libraries used for the Brazilian Multipurpose Reactor design, reactor cell and mesh structures, control rods effectiveness, isothermal reactivity coefficients and core dynamics due to reactivity insertions, the IPEN/MB-01 new plate-type core is being implemented at the Nuclear and Energy Research Institute (IPEN/CNEN-SP), SP-Brazil. It´s a tank-type research reactor. The core has a 4×5 configuration, with 19 fuel elements (U3Si2-Al, 2.8gU/cm³ and 19.75% enriched in U-235), plus one aluminum block (internal irradiation position). As burnable poison, cadmium wires were used, once they are also employed at the RMB project to control the power density and the excess of reactivity during its operation. The core is reflected by four boxes of heavy water (D2O) and its maximum nominal power is 100W. Thereby, a Monte Carlo modeling was developed using the Monte Carlo N-Particle code (MCNP), along with NJOY, for processing the materials nuclear cross sections. This modeling for the IPEN/MB-01 new plate-type core is presented and some neutronic calculations were also depicted in this paper.
The correlation matrix for the effective delayed neutron parameters of the IPEN/MB-01 reactor
2020 - SANTOS, ADIMIR dos; DINIZ, RICARDO
The correlation matrix for the effective delayed neutron parameters of the IPEN/MB-01 reactor has been successfully built in this work. A standard procedure employed in several least-squares approaches was adopted to cope with this task. One of the most important applications of the effective delayed neutron parameters is to serve as input data for the relationship between reactivity and asymptotic period of a nuclear reactor given by the Inhour equation. Employing this equation, the reactivity was calculated for several periods both negative and positive. The reactivity error propagation was considered with and without the correlation matrix. The analyses of this procedure reveal that the consideration of the correlation matrix is very important. In general, the introduction of the correlation matrix reduces the overall uncertainty by a reasonable amount. There are huge cancellations in the uncertainty analyses. The analyses also reveal that the uncertainty in the reactivity will depend on the specific period range where this quantity is considered. Considering the correlation and for most of the period range considered, the reactivity uncertainties for negative periods are around 3.5% while for positive ones they are nearly 2%. If the correlation matrix is not considered the reactivity uncertainties are as high as 6%. All uncertainties considered in this work are 1-r values. There are two extreme cases where the correlation matrix plays no role; very large negative periods and very small positive periods. In the first case, the first decay constant plays a fundamental role while in the second the prompt neutron generation is of major importance. The experiments performed at the IPEN/MB-01 reactor and evaluated for inclusion in the IRPhE handbook for the determination of the effective delayed neutron parameters will be extremely benefited considering the inclusion of their correlation matrix. The final product can be considered extremely useful to validate methods and nuclear data related to the reactivity determination of thermal reactors fueled with Uranium.
Impact of 235U resonance parameter evaluation in the reactivity prediction
2017 - LEAL, LUIZ; SANTOS, ADIMIR dos; IVANOV, EVGENY; IVANOVA, TATIANA
Resonance parameter evaluation of the U-235 cross sections using the Reich-Moore formalism was done with the computer code SAMMY from 0 to 2.25 keV to address issues with capture cross-section and standard fission cross-section values. The evaluation includes recent capture and fission cross-section measurements as well as high-resolution data used in previous U-235 evaluation. Moreover the new U-235 resonance parameter evaluation has been used in the calculation of a new benchmark experiment performed at the IPEN/MB-01 research reactor. The experiment, named the inversion point of the isothermal reactivity coefficient, is used to test temperature effects at low temperature. The results demonstrate that the new U-235 evaluation has greatly improved the prediction of reactivity temperature coefficient in contrast to previous evaluations. This paper is outlined in two parts, namely the first part deals with the description of the U-235 resonance analysis and evaluation up to 2.25 keV, and the second part presents the results of the isothermal reactivity coefficient calculations performed on the IPEN/MB-01 reactor.
A proposal for a subcritical reactivity meter based on gandini and salvatores point kinetics equations for multiplying subcritical systems
2015 - PINTO, LETICIA N.; GONNELLI, EDUARDO; SANTOS, ADIMIR dos
Elaboração de uma base de dados experimentais para obtenção do nível de subcriticalidade do reator IPEN/MB-01
2007 - COSTA, PEDRO de C.; SANTOS, ADIMIR dos
Control rod calibration and reactivity effects at the IPEN/MB-01 reactor
2013 - PINTO, LETICIA N.; GONNELLI, EDUARDO; SANTOS, ADIMIR dos
The evaluation of the effective kinetic parameters and reactivity of the IPEN/MB-01 reactor for the international reactor physics experiment evaluation project
2014 - SANTOS, ADIMIR dos; DINIZ, RICARDO
Experiment planning of subcritical reactivity determination using high order statics of neutron counting
2010 - SERRA, ANDRE da S.; PASCHOLATI, PAULO; SANTOS, ADIMIR dos
Absolute measurement of betasub(eff) based on feynman-alfa experiments and the two-region model in the IPEN/MB-01 research reactor
2007 - KURAMOTO, RENATO Y.R.; SANTOS, ADIMIR; JEREZ, ROGERIO; DINIZ, RICARDO