SANDRA REGINA DAMATTO

SANDRA REGINA DAMATTO

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Challenges in measuring 22Na in rainfall by gamma spectrometry in the city of São Paulo, Brazil
2023 - DAMATTO, S.R.; DOMINGOS, R.M.; TEIXEIRA, L.; ISIKI, V.L.; ALENCAR, M.M.; LEONARDO, L.
Na-22 is a naturally occurring radionuclide of cosmogenic origin with half live of 2.6 years, being a beta and gamma emitter (541keV and 1274.5keV, respectively). This cosmogenic radionuclide is mainly formed when cosmic rays interact with argon nucleus, occurring a fragmentation of this nucleus. The process of production of 22Na occur continually in upper atmosphere, lower stratosphere and rainfall is the predominantly process of deposition of cosmogenic radionuclides in terrestrial surface. Na-22 together with 7Be (T1/2) = 53.3 d, gamma ray 476.7keV) can be used as tracers in studies of aerosol transport between layers of the atmosphere. At the same time 22Na is rarely used in these studies due to its extremely low abundance in rainfall. The objectives of this work were to present the first results 22Na activity concentration measured in rainfall collected at the IPEN campus located in São Paulo, Brazil. Large volumes of rainfall samples were collected from October 2022 to April 2023, totaling 20 samples, and 22Na activity concentration was measured by non-destructive gamma-ray spectrometry using a coaxial Be-layer HPGe detector with 46% relative efficiency and associated electronic devices and live counting time varying from 250,000 s to 500,000 s; the rainfall volumes ranged from 14 L to 164 L. The collection container was previously acidified with 1mol L-1 HNO3 to avoid loss of radionuclide by absorption on the container walls. The first eight rainfall samples were collected in a catchment area of 1m2, which was not enough to measure the radionuclide, since all the determined results were smaller than the detection limit of the methodology. After these results, it was decided to increase the catchment area by collecting rainfall samples from the roof of the laboratory building, in an area of 78 m2; the container used to collect samples from this area was also acidified with 1 mol L-1 HNO3. In this new area, 12 rainfall samples were collected, however, as the volume of rainfall was very large in the rains collected, only one sample was acidified, a rainfall of 2 mm and a volume of 98 L; in the other samples, the large volume of rain did not allow the water to become acidic because the collection container overflowed with water. In the acidified rainfall sample, the result of 0.725 ± 0.252 Bq L-1 was determined for the radionuclide 22Na. With this result, it is possible to prove the importance of both the catchment area and the acidulation of the sample in the determination of trace radionuclides in rainfall samples.
Two years of continuous monitoring of 7Be and 210Pb in rainfall collected at the IPEN campus, São Paulo, Brazil
2023 - CASTRO, J.O.; DOMINGOS, R.M.; DAMATTO, S.R.; RODRIGUES, C.E.C.; ISIKI, V.L.; NETO, J.O.A.
The naturally occurring radionuclides 7Be and 210Pb are produced in the atmosphere and used as tracers of a wide variety of processes that occur in the Earth's atmosphere and surface. The cosmogenic radionuclide 7Be (T1/2 = 53.3 d), is produced in the upper atmosphere by cosmic ray spallation of oxygen and nitrogen; 210Pb (T1/2 = 22.3 y), a natural radionuclide from 238U series can be found in the atmosphere, as a product of 222Rn decay that emanates from the ground. Both natural radionuclides can be used as tracers for heavy metals and pollutants in the environment, tracer of soil erosion, transport processes in watershed and sedimentation in lakes, among other examples. The activity concentration results of these radionuclides in rainfall, when combined with meteorological information, help to understand how aerosol particles are transported in the air and removed from the atmosphere by the action of rainfall. The objectives of this work were to determine the activity concentrations of the natural radionuclides 7Be and 210Pb in rainfall samples over a period of two years, from January 2021 to December 2022, in each rainy event that occurred on the IPEN campus, located in the city of São Paulo, Brazil. Be-7 activity concentrations were measured by non-destructive gamma-ray spectrometry using a coaxial Be-layer HPGe detector with 25% relative efficiency and associated electronic devices and live counting time varying from 80,000 s to 300,000 s; 210Pb activity concentrations were measured by gross beta counting in a low background gas flow proportional detector, after radiochemistry procedure. The annual rainfall indices for 2021 and 2022 were 1093 mm and 1391 mm, respectively. Activity concentrations for 7Be ranged from 0.459 ± 0.038 Bq L-1 to 8.96 ± 0.57 Bq L-1 and for 210Pb from 0.015 ± 0.001 to 0.98 ± 0.01 Bq L-1 in the studied period. The results obtained of 7Be and 210Pb in rainfall were correlated to seasons, precipitation, temperature, and sunspot number for 7Be. The higher values obtained for the concentrations were in winter and spring time presenting good correlations with the amount of precipitation and sunspot number and a clear seasonal variation.
Determinação de elementos traços em testemunhos de sedimento do reservatório Biritiba-Mirim, São Paulo utilizando a técnica de INAA
2023 - SILVA, THIAGO C.; DAMATTO, SANDRA R.
Determinação de 210Pb em amostras pluviométricas coletadas no Instituto de Pesquisas Energéticas e Nucleares (IPEN)
2023 - CASTRO, JULIA O.; DAMATTO, SANDRA R.
In situ characterization of NORM waste from the oil industry
2022 - DELLAMANO, J.C.; DAMATTO, S.R.; CARVALHO, R.N.; MENEGHINI, A.A.; MARUMO, J.T.; MADUAR, M.F.; VICENTE, R.
In the oil industry, radioactive wastes are generated in the oil production platforms containing natural radionuclides, such as 226Ra and 228Ra, the NORM waste. This waste is mainly in the form of produced water, sludge and scales which should be characterized for the correct final destination. The Brazilian laws establish that the NORM wastes from the oil production must comply with Law 10308 of November 20, 2001, which determine in its article 7, "The disposal of radioactive waste of any kind in the oceanic islands, the continental shelf and the Brazilian territorial waters is prohibited." Therefore, the NORM waste from offshore oil extraction rigs should be transported to onshore facilities. There are two options for the destination of this material: industrial landfill, in the case of activity concentrations are below clearance limits established by Brazilian Nuclear Commission, CNEN; or on the contrary, to intermediate storage facilities, until final disposal is decided. Currently, the oil production companies take samples from the waste and send them to radiometric laboratories in order to evaluate their activity concentration by gamma spectrometry. The complete process takes more than six months to be concluded. Nuclear and Energy Research Institute, IPEN, is making efforts to solve the management problems of NORM waste from oil extraction, including conduct research aiming at characterizing the waste. The objective of the paper is to present the results of in situ characterization of drums containing oil sludge using portable gamma spectrometers.
In situ characterization of NORM waste from the oil industry
2020 - DELLAMANO, JOSE C.; DAMATTO, SANDRA R.; MADUAR, MARCELO F.; MARUMO, JULIO T.; CARVALHO, RICARDO N.; VICENTE, ROBERTO; MENEGHINI, ARTHUR A.
Influência da altura de coleta na concentração de atividade do radionuclídeo cosmogênico 7Be
2022 - DOMINGOS, RAFAEL M.; DAMATTO, SANDRA R.
Trace elements determined by INAA in a sediment core dated by Pb-210 method from Laguna de Peña, Uruguay
2022 - DAMATTO, S.R.; RODRIGUES, C.E.C.
Study of 7Be activity concentration in rainfall as a function of sampling height
2022 - ALMEIDA NETO, J.O.; DAMATTO, S.R.; MADUAR, M.F.; LEONARDO, L.; TEIXEIRA, L.F.; DOMINGOS, R.M.
Natural radioactivity in oilseeds commercialized in the city of São Paulo, Brazil
2022 - LEONARDO, L.; DAMATTO, S.R.; MADUAR, M.F.