MARCIA PIRES DE CAMPOS

MARCIA PIRES DE CAMPOS

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Radon concentrations in a nuclear reactor center in Brazil
2021 - SILVA, PAULO S.C. da; CAMPOS, MARCIA P. de; EL HAJJ, THAMMIRIS M.; REIS, GUILHERME de L.
Radiation workers are normally exposed to doses resulting from their day-to-day activities. Besides that, background radiation, such as radon, can contribute to the exposure rates. The radionuclide 222Rn is a noble gas belonging to the uranium series, and its indoor concentration in the air depends on the exhalation from surrounding soil and the exhalation from building materials. Radon exhaling from porous building materials containing high uranium concentrations can become a significant exposure factor in areas with limited ventilation. The objective of this study was to evaluate the 222Rn concentrations in the radiochemistry and radiometric laboratories in the nuclear reactor building of the Nuclear Reactor Center (CERPq) located in the Institute of Nuclear and Energy Research (IPEN), São Paulo, Brazil. Measurements were done using a Radon Gas Monitor, model RAD7, equipped with a solid-state alpha detector. A passive method (SSNTD) was also used, consisting of square pieces of C-39 foils (2.5 cm × 2.5 cm) placed within small diffusion chambers. The CR-39 detectors were etched in KOH 30% solution at 80 °C for 5.5 h in a constant-temperature bath. After etching, the detectors were washed, dried, and scanned using a microscope to obtain the track density measurements. The activity concentrations measured with both techniques varied from 52 to 103 Bq m−3 in the studied areas of the CERPq. These values may be compared to the reference level of 100 Bq m−3 established by the World Health Organization to ensure safety environments.
Radiological evaluation of bricks made with NORM residue
2019 - CAMPOS, MARCIA P. de; NISTI, MARCELO B.; PASCHOALIN FILHO, JOAO A.; MAZZILLI, BARBARA P.
Radon concentrations on the nuclear and radioactive instalations of nuclear reactor center – CRPQ/IPEN
2019 - SILVA, PAULO S.C. da; CAMPOS, MARCIA P. de; REIS, GUILHERME de L.
Nuclear and radioactive workers are normally exposed to dose resulting from their day by day activities. Besides that, the ubiquitous radon distribution can also contribute for the exposure rates. The radionuclide 222Rn is a noble gas belonging to the uranium series and its indoor concentration in the air depend on exhalation from surrounding soil and on exhalation from building materials. Radon emanating from porous building materials may achieve large relevance in areas with high uranium concentrations and areas with limited ventilation. The objective of this study was to evaluate the 222Rn concentrations in the radiochemistry and radiometric laboratories and in the reactor nuclear building of the Nuclear Reactor Center (CERPq) located in the Nuclear and Energy Research Institute (IPEN). Measurements were done by using a Radon Gas Monitor, model RAD7, produced by Durridge Company equipped with a solid state alpha detector and a passive method, with SSNTDs placed within small diffusion chambers, as detectors square pieces (2.5 cm × 2.5 cm) of CR 39 foils were used. The CR 39 detectors were etched in KOH 30% solution at 80 °C for 5.5 h in a constant temperature bath. After etching, the detectors were washed, dried, and scanned under a Carl Zeiss microscope to obtain the track density measurements. The activity concentrations varied from 52 to 103 Bq m 3 for the measured areas in CERPq. These values are in accordance with what is stablished by the World Health Organization for safe environments of 100 Bq m 3.
Determinação da taxa de exalação do 222Rn no solo do IPEN
2019 - NISTI, M.B.; CAMPOS, M.P.; SILVA, G.M.; MAZZILLI, B.P.
Radiological implications of using phosphogypsum as building material
2018 - MAZZILLI, B.P.; CAMPOS, M.P.; NISTI, M.B.; MADUAR, M.F.
Phosphogypsum recycling in the building materials industry: assessment of the radon exhalation rate
2017 - CAMPOS, M.P.; COSTA, L.J.P.; NISTI, M.B.; MAZZILLI, B.P.
Phosphogypsum can be classified as a Naturally Occurring Radioactive Material (NORM) residue of the phosphate fertilizer industry. One of the main environmental concerns of its use as building material is the radon exhalation. The aim of this study is to measure the radon exhalation rate from plates and bricks manufactured with phosphogypsum from three installations of the main Brazilian producer, Vale Fertilizantes, in order to evaluate the additional health risk to dwellers. A simple and reliable accumulator method involving a PVC pipe sealed with a PVC pipe cover commercially available with CR-39 radon detector into a diffusion chamber was used for measuring radon exhalation rate from phosphogypsum made plates and bricks. The radon exhalation rate from plates varied from 0.19 ± 0.06 Bq m 2 h 1, for phosphogypsum from Bunge Fertilizers, from 1.3 ± 0.3 Bq m 2 h 1, for phosphogypsum from Ultrafertil. As for the bricks, the results ranged from 0.11 ± 0.01 Bq m 2 h 1, for phosphogypsum from Bunge Fertilizers, to 1.2 ± 0.3 Bq m 2 h 1, for phosphogypsum from Ultrafertil. The results obtained in this study for the radon exhalation rate from phosphogypsum plates and bricks are of the same order of magnitude than those from ordinary building materials. So, it can be concluded that the recycling of phosphogypsum as building material is a safe practice, since no additional health risk is expected from the radiological point of view.
Assessment of 222Rn concentration in the soil around IPEN facilities
2016 - CAMPOS, MARCIA P.; REIS, GUILHERME L.; NISTI, MARCELO B.; MAZZILLI, BARBARA P.
Radiological implications of using phosphogypsum as building material
2016 - MAZZILLI, BARBARA P.; MADUAR, MARCELO F.; NISTI, MARCELO B.; CAMPOS, MARCIA P. de
A comparison of analytical methods for screening gross alpha and beta radioactivity in water by liquid scintillation counting and gas flow proportional counting
2015 - NISTI, M.B.; FERREIRA, A.O.; CAMPOS, M.P.; SAUEIA, C.H.R.; MAZZILLI, B.P.
Radon levels in building basements and above-ground floors at São Paulo, Brazil
2015 - CAZULA, CAMILA D.; CAMPOS, MARCIA P.; MAZZILLI, BARBARA P.