ROBERTO VICENTE

ROBERTO VICENTE

(Fonte: Lattes)

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Degree in Physics from Universidade de São Paulo (1977); master degree in Nuclear Technology from Universidade de São Paulo (1980) and doctorate in Nuclear Technology from Universidade de São Paulo (2002). Has experience in radioactive waste management, acting on the following subjects: radioactive waste characterization, treatment and disposal; disposal of disused sealed radioactive sources. (Text obtained from the Currículo Lattes on November 25th 2021)

É bacharel em Física pela Universidade de São Paulo (1977), tem mestrado em Tecnologia Nuclear pela Universidade de São Paulo (1980) e doutorado em Tecnologia Nuclear pela Universidade de São Paulo (2002). Atualmente é tecnologista da Comissão Nacional de Energia Nuclear. Tem experiência na área de Engenharia Nuclear, com especialização em Gestão de Rejeitos Radioativos, atuando principalmente nos seguintes temas: gerenciamento, tratamento e deposição de rejeitos radioativos. (Texto extraído do Currículo Lattes em 25 nov. 2021)

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Dose estimation in abdominal CT scans using CT-EXPO software
2022 - SOUZA, D.C.B.; VICENTE, R.; SA, L.V.; SILVA, E.H.; OLIVEIRA, M.V.L.; CIDRAL, M.E.V.; FARIA, C.R.; CAMILO, N.F.
The application of ionizing radiation in diagnostic medicine has increased worldwide in the last decades. Computed Tomography (CT) is the main radiological procedure that contributes to the increase of the collective dose in the population. The aim of this study was to estimate the doses received by patients undergoing CT scans in a public hospital in Santa Catarina - Brazil, employing data from the DICOM header and utilizing the CT-Expo V. 2.7 software. The data were selected from 45 abdominal CT scans consisting of two series: pre-contrast and one post-contrast intravenous, of adult patients performed in December 2020. The spreadsheets with the data extracted from the DICOM headers were provided by the Santa Catarina Telemedicine System (STT). The effective dose and organ doses were calculated by CTDIvol and DLP values using the software. Overall, the organs that showed the higher equivalent doses were the kidneys (19.5 mSv), spleen (18.5 mSv), stomach (18.9 mSv), and liver (18.1 mSv). The estimated effective doses were 7.31 and 8.41 mSv, for non-contrast and contrast-enhanced examinations. The use of software such as CT-Expo can support the estimation of effective doses received by patients through the information extracted from the DICOM header. The presented methodology can be a useful tool to retrospectively estimate the doses in CT services in Brazil.
Dose estimation in abdominal CT scans from DICOM header data
2021 - SOUZA, DAIANE C.B.; VICENTE, ROBERTO; SA, LIDIA V. de; SILVA, EDILANE H.; OLIVEIRA, MARCUS V.L.; CIDRAL, MARIA E.V.; CAMILO, NAYTHYARA F.; FARIA, CAMILA R.
Preliminary studies on electron beam irradiation as a treatment method of radioactive oil sludge
2021 - TESSARO, A.P.G.; VICENTE, R.; MARUMO, J.T.; TEIXEIRA, A.C.S.C.; ARAUJO, L.G.
Radiation-induced advanced oxidation processes have been proposed for the treatment of various types of wastes. However, electron beam technologies for the removal of recalcitrant compounds in petroleum wastes are still poorly understood. This work aims at evaluating the effects on the degradation of organic matter from oil sludge by electron beam irradiation. Characterization methods were employed to identify the chemical elements present in the waste. Radiometric analysis was performed to identify radionuclides and measure dose rates. Preliminary immobilization of the untreated waste with cement indicated resistance values very close to the minimum established in national regulation. To treat the waste, an electron beam accelerator, model Dynamitron II, with variable current up to 25 mA was employed and the irradiation doses ranged from 20 to 200 kGy. Solutions were prepared with an initial H2O2 concentration of 1.34 mol·L-1. The effects on the removal of total organic carbon are discussed.
Inventorying the radionuclides in spent cartridge filters from the primary circuit of a nuclear research reactor by the dose-to-activity method
2020 - TESSARO, ANA P.G.; ARAUJO, LEANDRO G. de; VICENTE, ROBERTO
The high activity of spent cartridge filters from the cooling water polishing system of a nuclear research reactor precludes, in routine work of a waste characterization program, the usual method of radiochemical analysis of filter samples. For this waste, the dose-to-activity method, using a gamma spectrometer and a dose rate meter, is an alternative for the determination of the activities of the gamma emitters with acceptable accuracy. The ratio of photon peak-areas from different radionuclides, corrected by the detector energy-dependent efficiency, allowed estimating the proportions between the activities of the different radionuclides present. Finally, the simulation of the counting geometry, using the point-kernel method to estimate the air dose rate resulting from an arbitrary concentration of those radionuclides and the comparison of the calculated with the measured air dose rate have yielded the needed estimates of the activity concentrations. The aim of this paper is to report the development of the method applied for the determination of the concentration of the gamma-emitters present in cartridge filters from the IEA-R1 Nuclear Research Reactor.
Caracterização de embalados de rejeitos radioativos utilizando Microshield
2019 - SILVA, RODRIGO A. da; SUKADOLNIK, MIKAELL P.; TESSARO, ANA P.G.; SOUZA, DAIANE C.B. de; VICENTE, ROBERTO
Na extração de petróleo, há presença significativa de material radioativo de origem natural e, por isso, as empresas que realizam esse trabalho devem atender as normas de proteção radiológica estabelecidas pela Comissão Nacional de Energia Nuclear (CNEN). Determinar a concentração radioisotópica em rejeitos radioativos é um passo fundamental no processo de caracterização dos rejeitos e é essencial no tratamento, no transporte e na eliminação deles. Este estudo consistiu na utilização de medidas das taxas de dose e cálculos para estimativa do conteúdo radioativo presente em tambores com rejeitos provenientes da indústria de petróleo. Foi utilizado o programa para cálculo de blindagem Microshield. Os principais resultados obtidos foram os valores de taxa de dose e a espectrometria de emissão gama. O método baseado na medição das taxas de exposição em torno de embalados fornece boas aproximações quando as informações sobre emissores gama presentes nos embalados de rejeitos são obtidos por espectrometria gama.
Oil sludge treatment by electron beam irradiation
2019 - TESSARO, ANA P.G.; CASAS, ALEXANDRE L.; TEIXEIRA, ANTONIO C.S.C.; VICENTE, ROBERTO; MARUMO, JULIO T.; ARAUJO, LEANDRO G. de
Radiation induced advanced oxidation processes have been proposed for the treatment of various types of wastes. However, electron beam technologies for the removal of recalcitrant compounds in petroleum wastes are still poorly understood. This work aims at evaluating the effects on the degradation of organic matter from oil sludge by electron beam irradiation. The radiometric analysis was also performed to identify radionuclides and measure dose rates. An electron beam accelerator, model Dynamitron II, with variable current up to 25 mA was employed and the irradiation dose values ranged from 20 to 250 kGy. Solutions were prepared with an initial H2O2 concentration of 1.34 mol L 1. Samples without H2O2 addition, but with water were also evaluated. Control tests with dry and pulverized sludge were submitted to irradiation. The effects on the removal of total organic carbon and the sludge degradation are discussed.
Radioactive waste management Goiânia - São Paulo: 30 years later
2017 - SOUZA, D.C.B. de; GERALDO, B.; TESSARO, A.P.G.; ROSTELATO, M.E.C.M.; MARUMO, J.T.; CARVALHO, V.S.; BARBOSA, N.K.O.; VICENTE, R.
Considered the largest urban radiological accident in the world, the accident in Goiânia with Cesium-137 resulted in the death of four people and injuries in another 49, besides measurable levels of internal or exter-nal contamination in 129. The accident generated also environmental contamination and thousands of tons of radioactive waste that resulted from the response activities. The accident occurred as a result of the disman-tling of an equipment of radiotherapy by employees of a junkyard. Before the accident was identified, con-taminated materials were sent to recycling companies in the state of São Paulo. The objective of this work was to report the existence of waste from Goiânia accident in the state of São Paulo and to check the estimat-ed activities at the time of the waste conditioning by measuring the current dose rates in waste packages, allowing a refinement of previously applied calculations.
Characterization of filters cartridges from the water polishing system of IEA-R1 reactor: radiometric methods
2015 - TESSARO, ANA P.G.; VICENTE, ROBERTO