ANA PAULA GIMENES TESSARO

ANA PAULA GIMENES TESSARO

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Prospects for fungal bioremediation of unburied waste packages from the Goiânia radiological accident
2023 - TESSARO, ANA P.G.; ARAUJO, LEANDRO G. de; SILVA, THALITA T.; COELHO, EDNEI; CORREA, BENEDITO; ROLINDO, NATALIE C.; VICENTE, ROBERTO
Goiânia, the Goiás State capital, starred in 1987, where one of the largest radiological accidents in the world happened. A teletherapy machine was subtracted from a derelict radiotherapy clinic and disassembled by scavengers who distributed fragments of the 50 TBq 137CsCl source among relatives and acquaintances, enchanted by the blue shine of the substance. During the 15 days before the accident was acknowledged, contaminated recycling materials were delivered to recycling factories in four cities in the state of São Paulo, Brazil, in the form of recycling paper bales. The contaminated bales were spotted, collected, and stored in fifty 1.6 m3 steel boxes at the interim storage facility of the Nuclear and Energy Research Institute (IPEN). In 2017, a check of the content was performed in a few boxes and the presence of high moisture content was observed even though the bales were dry when conditioned and the packages were kept sealed since then. The main objective of this work was to report the fungi found in the radioactive waste after they evolved for 30 years in isolation inside the waste boxes and their role in the decay of the waste. Examination of the microbiome showed the presence of nematodes and fungal communities. The fungi species isolated were Aspergillus quadricinctus, Fusarium oxysporum, Lecanicillium coprophilumi, Scedosporium boydii, Scytalidium lignicola, Xenoacremonium recifei, and Pleurostoma richardsiae. These microorganisms showed a significant capacity to digest cellulose in our trials, which could be one of the ways they survive in such a harsh environment, reducing the volume of radioactive paper waste. These metabolic abilities give us a future perspective of using these fungi in biotechnology to remediate radioactively contaminated materials, particularly cellulose-based waste.
Further analyses of the unburied Goiania accident packages
2021 - SMITH, RICARDO B.; TESSARO, ANA P.G.; ROLINDO, NATALIE C.; VICENTE, ROBERTO
In 1987, in the city of Goiania, Brazil, a derelict teletherapy machine was disassembled by scavengers and Cs-137 was released in the environment, unleashing the biggest radiological accident in Brazil. During the 15 days before the accident was acknowledged, some contaminated materials were sold and delivered to recycling factories in a few cities in the state of Sao Paulo, Brazil, in the form of metal scrap and recycled paper bales. The contaminated material was then collected, the metal scrap was conditioned in forty-three 200-liter drums, and the paper bales were stored in fifty 1.6 cubic meter steel boxes at the interim storage of the Nuclear and Energy Research Institute (IPEN), in the city of Sao Paulo, and there remained ever since. In 2017, 30 years later, initial analyses were performed at a sample of these boxes, checking for their activity, weight, and incongruences between the original values recorded at the time of collection and the measurement results 30 years later. The results indicated that none of the boxes checked were close to the clearance limit and that, without any sort of treatment, this radioactive waste should be stored for at least 150 years more. Visual inspection could not be performed at that time. Nowadays, some of the boxes were opened and samples from the contaminated material inside were taken for analysis. The main objective of this work is to report the results from the evaluation of the physical state of this material. After these analyses, the treatment options for volume reduction that were previously proposed were reviewed, and the method that best suits the current characteristics of the waste was chosen.
Essays on nuclear energy and radioactive waste management
2021 - TESSARO, ANA P.G.; GERALDO, BIANCA; SOUZA, DAIANE C.B. de; ROMERO, FERNANDA; BISURI, INDRANIL; MARUMO, JULIO T.; CHEBERLE, LUAN T.V.; SACHDEVA, MAHIMA; ROSA, MYCHELLE M.L.; ROLINDO, NATALIE C.; SMITH, RICARDO B.; VICENTE, ROBERTO; SALVETTI, TEREZA C.
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.
Further analyses of the unburied Goiania Accident packages
2019 - SMITH, RICARDO B.; TESSARO, ANA P.G.; ROLINDO, NATALIE C.; VICENTE, ROBERTO
In 1987, in the city of Goiania, Brazil, a derelict teletherapy machine was disassembled by scavengers and Cs-137 was released in the environment, unleashing the biggest radiological accident in Brazil. During the 15 days before the accident was acknowledged, some contaminated materials were sold and delivered to recycling factories in a few cities in the state of Sao Paulo, Brazil, in the form of metal scrap and recycled paper bales. The contaminated material was then collected, the metal scrap was conditioned in forty-three 200-liter drums, and the paper bales were stored in fifty 1.6 cubic meter steel boxes at the interim storage of the Nuclear and Energy Research Institute (IPEN), in the city of Sao Paulo, and there remained ever since. In 2017, 30 years later, initial analyses were performed at a sample of these boxes, checking for their activity, weight, and incongruences between the original values recorded at the time of collection and the measurement results 30 years later. The results indicated that none of the boxes checked were close to the clearance limit and that, without any sort of treatment, this radioactive waste should be stored for at least 150 years more. Visual inspection could not be performed at that time. Nowadays, some of the boxes were opened and samples from the contaminated material inside were taken for analysis. The main objective of this work is to report the results from the evaluation of the physical state of this material. After these analyses, the treatment options for volume reduction that were previously proposed were reviewed, and the method that best suits the current characteristics of the waste was chosen.
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.
Desenvolvimento de métodos radiométricos para a caracterização de rejeitos radioativos
2015 - TESSARO, ANA P.G.
A aceitação de rejeitos radioativos em um repositório final depende, entre outras coisas, do conhecimento do inventário radioisotópico presente neles. Para obter essa informação, é necessário fazer a caracterização primária dos rejeitos de modo que a composição seja conhecida e oriente os passos seguintes da gestão. Os filtros cartucho que são utilizados no sistema de retratamento de água do reator de pesquisa IEA-R1 é um desses rejeitos. O IEA-R1 é um reator de pesquisa do tipo piscina, operando entre 2 e 5 MW, que utiliza a água como líquido de arrefecimento, moderador e blindagem biológica Além do seu uso em pesquisa, também é utilizado para produzir radioisótopos e irradiar amostras. Ele está localizado no Instituto de Pesquisas Energéticas e Nuclear, no campus da Universidade de São Paulo. Os filtros cartucho são utilizados para reter o material particulado em suspensão presente na água. Quando os filtros ficam saturados e são incapazes de manter o fluxo dentro dos limites estabelecidos, eles são substituídos e descartados como rejeito radioativo. Após um período de espera para o decaimento da atividade, são enviados para Gerência de Rejeitos Radioativos (GRR). O objetivo deste trabalho é apresentar os estudos realizados para determinar a atividade dos emissores gama presentes nos filtros cartucho. As atividades foram calculadas utilizando as taxas de dose medidas com detectores portáteis, as relações entre as taxas de emissão de fótons avaliadas por espectrometria gama, e o método de Point Kernel, que correlaciona a atividade de uma fonte com as taxas de dose a várias distâncias. O método descrito pode ser utilizado para determinar de modo rotineiro o inventário radioisotópico destes filtros, dispensando análises radioquímicas destrutivas, e a necessidade de calibração da geometria de medição.
Characterization of filters cartridges from the water polishing system of IEA-R1 reactor: radiometric methods
2015 - TESSARO, ANA P.G.; VICENTE, ROBERTO