Abstract: One way to better manage mining waste may be to reduce its quantity by reusing it. Using waste as construction material in the case of the niobium industry might be feasible, even though it carries radioactive elements. This study evaluates the radiological impact of using niobium waste as a building material. Samples of niobium waste with and without granulometric classification were tested. Moreover, concrete proof bodies, concrete plates, and common commercially available aggregates and cement were radiologically assessed for comparison purposes. The main conclusion is that niobium waste might be both physically and radiologically suitable to manufacture concrete respecting boundary conditions.

Palavras-Chave: sustainability; niobium; mining; residues; radon 220; radon 222; risk assessment; building materials; naturally occurring radioactive materials; exhalation

SILVA, PAULO S.C. da; EL HAJJ, THAMMIRIS M.; DANTAS, G.A.S.A.; DELBONI JUNIOR, HOMERO; GANDOLLA, MAURO. Activity concentration of the uranium and thorium series and exhalation rates of 222Rn and 220Rn in building material derived from niobium residues. Journal of Building Engineering, v. 46, p. 1-10, 2022. DOI: 10.1016/j.jobe.2021.103657. Disponível em: http://repositorio.ipen.br/handle/123456789/33152. Acesso em: $DATA.

Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.

Como referenciar este item

Abstract: Phosphogypsum is a residue that has been used by the cement industry as a substitute for the natural gypsum, used as a clinker additive during the production of Portland cement. There is a potential increase in this residue consumption since large amounts of phosphogypsum are generated as outcome of the phosphate fertilizer industries. However, phosphogypsum can be considered a source of radioactive contamination due to the presence of 226Ra in its composition. Depending on the concentration of 226Ra, from the radiological protection point of view, this may cause a problem because this radionuclide and its direct decay product 222Rn along with other decay products, represent the largest fraction of radiation internal dose received by people. In order to evaluate the level of radiological risk that may be associated with the use of phosphogypsum, it is necessary to identify the concentration of 226Ra in building materials. The aim of this research is to analyze samples of phosphogypsum in relation to the concentrations of 226Ra, determined indirectly through 222Rn activity measurements. This measurement process has the advantage of being fast, convenient and relatively inexpensive when compared to traditional methods of 226Ra concentration in samples measurements. The proposed physical-mathematical model was used to establish radium concentration from radon exhalation rate from cement mortar samples. The 222Rn activity measurements were performed with a portable detector with cubic phosphate samples with 50 mm edges each placed in a closed atmosphere of the sampling chamber until secular equilibrium is achieved. Obtained concentrations of radium activity in studied samples of phosphogypsum and cement mortars were found below the limits recommended by CNEN and international regulation.

Palavras-Chave: building materials; concentration ratio; exhalation; gypsum cements; phosphates; radiation detectors; radiation protection; radioactivity; radium 226; radon 222

GERALDO, R.R.; PASCHUK, S.A.; BARRETO, R.C.; CORREA, J.N.; ZAHN, G.S.; SILVA, P.S.C. da; SILVA, A.M. da; NARLOCH, D.C.; ARAUJO, I.C. Application of a semi-empirical model for the evaluation of radium activity in phosphogypsum used as component of clinker. Brazilian Journal of Radiation Sciences, v. 9, n. 1A, p. 1-15, 2021. DOI: 10.15392/bjrs.v9i1A.1518. Disponível em: http://repositorio.ipen.br/handle/123456789/32133. Acesso em: $DATA.

Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.

Como referenciar este item

Abstract: The preparation of novel triply-doped bifunctional Fe3O4/ZnS@LaF3:xCe3+,xGd3+,yTb3+ (x = 5; y = 5, 10 and 15 mol%) nanocomposites with efficient optical and magnetic features has been reported. The ZnS semiconductor functionalized Fe3O4 particles were coated with LaF3:RE3+ materials via a chitosanassisted co-precipitation method. The size of iron oxide B7.2 nm and trigonal structures of bifunctional nanostructures were confirmed through X-ray diffraction and high-resolution transmission electron microscopy. The static magnetic measurements supported and manifested the superparamagnetic behavior of the materials at 300 K. A broad emission band was observed in the blue region (400–550 nm) due to the sulphur vacancy on the surface of the Fe3O4/ZnS nanocomposite. For a triply doped bifunctional nanostructure, the excitation spectra revealed broad absorption bands centered at around 270 nm, which were attributed to the 4f(7F7/2) - 5d interconfigurational transition of the Ce3+ ion accompanied by narrow absorption lines arising from the 4f–4f intraconfigurational transitions of the Tb3+ ion. The emission spectra of the nanocomposites showed characteristic narrow emission lines assigned to the 5D4 - 7FJ transitions (J = 6–0) of the Tb3+ ion. The energy transfer process from the Ce3+ - Gd3+ - Tb3+ ions has also been presented and discussed. Furthermore, the structural, photoluminescence and magnetic properties of Fe3O4/ZnS@LaF3:RE3+ suggested that it may be an efficient candidate for magnetic light-converting molecular devices (MLMCDs) and high energy radiation detection.

Palavras-Chave: fluorescence; nmr imaging; iron oxides; buildings; building materials; nanoparticles; zinc sulfides; lanthanum fluorides; cerium ions; gadolinium ions; terbium ions; nanocomposites

SHRIVASTAVA, NAVADEEP; KHAN, L.U.; KHAN, Z.U.; VARGAS, J.M.; MOSCOSO-LONDONO, O.; OSPINA, CARLOS; BRITO, H.F.; JAVED, YASIR; FELINTO, M.C.F.C.; MENEZES, A.S.; KNOBEL, MARCELO; SHARMA, S.K. Building block magneto-luminescent nanomaterials of iron-oxide/ZnS@LaF3:Ce3+,Gd3+,Tb3+ with green emission. Journal of Materials Chemistry C, v. 5, n. 9, p. 2282-2290, 2017. DOI: 10.1039/c6tc05053k. Disponível em: http://repositorio.ipen.br/handle/123456789/27861. Acesso em: $DATA.

Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.

Como referenciar este item

Abstract: Granitic rocks, widely used as building materials, are known to contain natural radionuclides and can be an important source of radiation for the population. Thirty-four samples of granite rocks from geological occurrences in Paraná state were measured with detector for evaluation of 226Ra, 232Th and 40K activity concentrations. The effective annual external dose was evaluated from these radionuclides activities using a dosimetric room model with dimensions 4 m x 5 m x 2.8 m in which all walls are internally coated with 2 cm thickness granites and considering the annual exposure time of 7000 h, suggested by the European Commission on Radiological Protection for superficial coating materials. The internal exposure was evaluated from radon air concentration of the model room, simulated from an exhalation rate of 222Rn, determined with CR-39 solid state nuclear track detectors by the sealed can technique, considering a ventilation rate of 0.5 h-1 and the same annual exposure time of 7000 h. The results for external gamma rays showed an increase in the annual effective dose ranging from 96 ± 4 μSv.a-1 to 223 ± 7 μSv.a-1 and, for radon inhalation, an increase in the ranging from 0.4 ± 0.04 μSv.a-1 to 70 ± 4 μSv.a-1. All results stayed below the recommended value by the European Commission on Radiological Protection, of 1 mSv.a-1.

Palavras-Chave: building materials; environmental effects; high-purity ge detectors; inhalation; potassium 40; radiation doses; radiation protection; radium 226; radon 222; thorium 232

FERREIRA, A.O.; PECEQUILO, B.R.S. Dose rates evaluation of some granitic rocks from the Paraná state. Brazilian Journal of Radiation Sciences, v. 9, n. 1A, p. 1-11, 2021. DOI: 10.15392/bjrs.v9i1A.1242. Disponível em: http://repositorio.ipen.br/handle/123456789/32079. Acesso em: $DATA.

Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.

Como referenciar este item

Abstract: Background: The use of natural radioactive building materials could be a health risk for both dwellers and mining workers. Therefore, a quick and effective method to test batches of rock samples is needed. Nevertheless, there is no reference value for maximum exhalation rates for building materials, except radiological hazard indices that do not measure gas exhalation rates directly. Objectives: This article investigated the correlations between Gamma Index and radon and thoron exhalation rates, and the proportions of radon and thoron in samples. Moreover, the main objectives were to analyze the feasibility of screening problematic samples for indoor use through a portable radiation detector (CoMo 170), which consists of a quick analysis at very low cost, and to simulate indoor concentration of radon using the measured exhalation rates of dimension stone slabs. Design: Best-selling dimension stone slabs were submitted to the following assays: gamma spectrometry, radon and thoron exhalation analysis using scintillation cell, and radioactivity measurement using a portable detector. Univariate and multivariate statistical analyses were conducted using Statistica 13 software. Results: The average activity concentrations measured were 971 ± 58.6 Bq/kg of 40K, 184 ± 9 Bq/kg of 232Th, and 74 ± 3 Bq/kg of 226Ra. The maximum activity concentrations of 40K, 232Th, and 226Ra series were 1,734 ± 100 Bq/kg, 2,667 ± 109 Bq/kg, and 596 ± 2 Bq/kg, respectively. The average exhalation rate of 222Rn was 406 ± 20 Bq/h m2. Conclusions: The main recommendations arising from this study are as follows: a portable radiation detector (CoMo 170) could be used as a screening method for selected samples; Gamma Index limit value = 1 for dimension stone slabs could be adopted when assessing radon and thoron exhalation; and the surface radon exhalation rate should be measured as a basis of recommendation for surface treatment before sales. Finally, thoron exhalations should be considered in radiological assessment, as 57% of the samples had higher thoron exhalation rates than radon.

Palavras-Chave: construction; buildings; building materials; radioactive minerals; radon; radon 220; radiation protection; gamma radiation; natural radioactivity; radiation doses; exhalation; regulations

EL HAJJ, THAMMIRIS M.; GANDOLLA, MAURO P.A.; SILVA, PAULO S.C. da; JULIÃO, EDUARDO L.; VILLANUEVA, JOSÉ-LUIZ G.; DELBONI JUNIOR, HOMERO. A method for radiologically evaluating indoor use of dimension stone considering radon exhalation rates. Journal of the European Radon Association, v. 1, p. 1-15, 2020. DOI: 10.35815/radon.v1.3632. Disponível em: http://repositorio.ipen.br/handle/123456789/31463. Acesso em: $DATA.

Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.

Como referenciar este item

Abstract: Phosphogypsum (PG), a by-product from the phosphoric acid industry, is being worldwide stockpiled, posing environmental problems. Viability of the PG safe re-use in civil construction has been studied, as PG can contain natural radionuclides in significant concentrations. We propose a policy for using PG as a building material, limiting the total concentration of 226Ra plus 228Ra by mixing PG with natural gypsum. It was concluded that PG from the largest Brazilian deposits could be used without any dilution, when the sum of the activity concentrations of 226Ra and 228Ra does not exceed 150 Bq kg-1. For higher values, the approach is to mix PG with increasing amounts of natural gypsum, so that the final concentration does not exceed 1000 Bq kg-1. We show that PG re-use in such a way is feasible in terms of radiological protection and recommended to minimize PG piles environmental impact.

Palavras-Chave: building materials; gypsum; natural radioactivity; radiation hazards; radiation protection; radium 226; radium 228; waste product utilization

MADUAR, M.F.; MAZZILLI, B.P.; NISTI, M.B. Radiation hazard indices in the application of phosphogypsum mixtures as a building material: proposal for a Brazilian regulation. Brazilian Journal of Radiation Sciences, v. 7, n. 3, p. 1-13, 2019. DOI: 10.15392/bjrs.v7i3.839. Disponível em: http://repositorio.ipen.br/handle/123456789/30472. Acesso em: $DATA.

Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.

Como referenciar este item

Abstract: This paper presents the results of X-ray fluorescence (XRF) analysis of bricks sampled from historical places in Pernambuco, a state in the northeastern region of Brazil. In this study, twenty bricks found in historical sites were analyzed. Two bricks made in the 17th century, presumably used as ballast in ships coming from Holland, five locally manufactured bricks: one from 18th century, three from 19th century, and one from 20th century, and thirteen bricks collected from a recent Archeological investigation of Alto da Sé, in the town of Olinda. Qualitative determination of the chemical elements present in the samples was undertaken using a self-assembled portable XRF system based on a compact X-ray tube and a thermoelectrically cooled Si-PIN photodiode system, both commercially available. X-ray diffraction analysis was also carried out to assess the crystalline mineral phases present in the bricks. The results showed that quartz (SiO2) is the major mineral content in all bricks. Although less expressive in the XRD patterns, mineral phases of illite, kaolinite, anorthite, and rutile are also identified. The trace element distribution patterns of the bricks, determined by the XRF technique, is dominated by Fe and, in decreasing order, by K, Ti, Ca, Mn, Zr, Rb, Sr, Cr, and Y with slight differences among them. Analyses of the chemical compositional features of the bricks, evaluated by principal component analysis of the XRF datasets, allowed the samples to be grouped into five clusters with similar chemical composition. These cluster groups were able to identify both age and manufacturing sites. Dutch bricks prepared with different geological clays compositions were defined.

Palavras-Chave: archaeology; archaeological sites; building materials; bricks; manufacturing; construction; x-ray fluorescence analysis

ASFORA, VIVIANE K.; BUENO, CARMEN C.; BARROS, VINICIUS M. de; KHOURY, HELEN; VAN GRIEKEN, RENE. X-ray spectrometry applied for characterization of bricks of Brazilian historical sites. X-Ray Spectrometry, v. 50, n. 1, p. 45-52, 2021. DOI: 10.1002/xrs.3194. Disponível em: http://200.136.52.105/handle/123456789/31660. Acesso em: $DATA.

Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.

Como referenciar este item