BIANCA GERALDO
4 resultados
Resultados de Busca
Agora exibindo 1 - 4 de 4
Artigo IPEN-doc 27080 Radiochemical method for characterization of the filter cartridges from the IEA-R1 reactor2016 - GERALDO, BIANCA; VICENTE, ROBERTO; FERREIRA, ROBSON J.; MADUAR, MARCELO F.; GOES, MARCOS M.; MARUMO, JULIO T.The filter cartridges used in water purification system of the IEA-R1 research reactor become radioactive waste after the end of their useful life. The characterization of this waste is one step in their management, which aims at identifying and quantifying the radionuclides present, including those known as "difficult to measure" (DTM) radionuclides. Wastes from nuclear reactors contain fission and activation products and transuranic elements, only few of them emitting gamma radiation measurable by simple gamma spectrometry methods. In routine waste management activities, the concentrations of the DTM can only be estimated by indirect methods such as scaling factors. The method of the scaling factors uses empirically determined proportions between the concentrations of DTM radionuclides and that of easily measurable gamma emitters called key nuclides (KN), to calculate DTM concentrations. Determining the scaling factors for the filter cartridges is a hard task when the number of samples is large, not only because the preparation of samples is difficult but also because the number of radionuclides to analyze is large. If it can be demonstrated that DTM and KN are both distributed evenly in the filters, less samples from each filter are necessary, reducing lab work. The aim of this paper is to present the results of the assessment of homogeneity along the filter cartridges by gamma spectrometry of chemically reduced samples. Five thin slices of five filters were burnt and the ashes quantitatively dissolved and the activity concentration of the solutions determined by gamma spectrometry.Artigo IPEN-doc 26681 Radiochemical characterization of spent filter cartridges from the primary circuit of a research reactor2019 - GERALDO, BIANCA; ARAUJO, LEANDRO G. de; TADDEI, MARIA H.T.; FERREIRA, MARCELO T.; MADUAR, MARCELO F.; VICENTE, ROBERTO; MARUMO, JULIO T.Radiochemical-based analyses have been used for the characterization of radioactive waste. Nevertheless, the determination of alpha, beta and gamma emitters by radiochemical analysis of spent cartridge filters from a swimming-pool type reactor has not been previously addressed. This work aims at identifying and quantifying the radionuclides present in this waste, including the difficult to measure radionuclides. The distribution of the radionuclides in the filter was investigated by the determination of gamma-emitting nuclides and the z-score of the measured activity concentrations. The results indicated that all the filters are homogeneous, meeting the homogeneity criteria recommended by the International Atomic Energy Agency.Artigo IPEN-doc 24425 Radioactive waste management Goiânia - São Paulo: 30 years later2017 - 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.Artigo IPEN-doc 19261 Utilization of radioanalytical methods for the determination of isotopes of U, Pu and Am in activated charcoal from IEA-R1 reactor2013 - GERALDO, BIANCA; TADDEI, MARIA H.T.; MARUMO, JULIO T.