Decay Chain Deduction of Uranium Fission Products.

Delayed gamma spectrum is the fingerprint of uranium materials in arms control verification technology. The decay chain is simplified into basic state linear chain and excitation state linear chain to calculate and analyze the delayed gamma spectra of fission products. Formulas of the changing rule for nuclide number before and after zero-time are deduced. The C program for calculating the delayed gamma ray spectra data is constructed, and related experiments are conducted to verify this theory. Through analysis of the delayed gamma counts of several nuclides, the calculated results are found to be consistent with experimental values.

Effects study on the thermal stresses in a LEU metal foil annular target.

The effects of fission gas pressure, uranium swelling and thermal contact conductance on the thermal-mechanical behavior of an annular target containing a low-enriched uranium foil (LEU) encapsulated in a nickel foil have been presented in this paper. The draw-plug assembly method is simulated to obtain the residual stresses, which are applied to the irradiation model as initial inputs, and the integrated assembly-irradiation process is simulated as an axisymmetric problem using the commercial finite element code Abaqus FEA. Parametric studies were performed on the LEU heat generation rate and the results indicate satisfactory irradiation performance of the annular target. The temperature and stress margins have been provided along with a discussion of the results.

Toxicity assessment of the water used for human consumption from the Cameron/Tuba City abandoned uranium mining area prior/after the combined electrochemical treatment/advanced oxidation.

The purpose of this work was detailed physicochemical, radiological, and toxicological characterization of the composite sample of water intended for human consumption in the Cameron/Tuba City abandoned uranium mining area before and after a combined electrochemical/advanced oxidation treatment. Toxicological characterization was conducted on human lymphocytes using a battery of bioassays. On the bases of the tested parameters, it could be concluded that water used for drinking from the tested water sources must be strictly forbidden for human and/or animal consumption since it is extremely cytogenotoxic, with high oxidative stress potential. A combined electrochemical treatment and posttreatment with ozone and UV light decreased the level of all physicochemical and radiological parameters below the regulated values. Consequently, the purified sample was neither cytotoxic nor genotoxic, indicating that the presented method could be used for the improvement of water quality from the sites highly contaminated with the mixture of heavy metals and radionuclides.

Riscos, saúde e alternativas de produção de conhecimentos para a justiça ambiental: o caso da mineração de urânio em Caetité, BA / Risks, health and knowledge production alternatives for environmental justice: the case of uranium mining in Caetité, BA

No município de Caetité, sertão baiano, situa-se a única mina de urânio em atividade no Brasil, operada desde 2000 pelas Indústrias Nucleares do Brasil (INB). Esta empresa tem sua atuação bastante questionada por comunidades locais e movimentos sociais da região, os quais alegam que a mesma omite informações sobre os riscos e impactos ambientais e à saúde relacionados ao empreendimento.Suspeitas de contaminação ambiental são reforçadas pelos acidentes ocorridos,sobretudo pelos episódios de vazamento de material radioativo para o ambiente. Portanto, verifica-se, em Caetité, um cenário de desinformação e incertezas quanto aos riscos e impactos potencialmente atribuídos as atividades de mineração e beneficiamento de urânio na região, que atingem, basicamente, trabalhadores da mina e comunidades rurais vizinhas. As abordagens técnico-científicas clássicas de investigação e produção de conhecimentos mostram-se limitadas para lidar com situações que envolvem riscos complexos, sobretudo em contextos de conflito e injustiças ambientais, como ocorre com a operação da mina de urânio em Caetité. Assim, diante do quadro apresentado, esta tese busca realizar uma reflexão crítica sobre a importância de estratégias alternativas de produção de conhecimentos, as quais valorizem e incorporem o saber situado dos sujeitos atingidos, a fim de possibilitar uma melhor compreensão, mais contextualizada, de riscos tecnológicos complexos e suas implicações para o ambiente e a saúde. Para tanto, são tomadas como referência experiências participativas e integradas de produção de conhecimentos acerca dos riscos e impactos verificados junto às atividades de mineração e beneficiamento de urânio em Caetité...

In the municipality of Caetité, semi-arid region of Bahia, it is located the only active uranium mine in Brazil, which is operated by the Brazilian Nuclear Industries (INB) since 2000. This company has its operations very questioned by local communities and social movements. They claim that INB omits information about environmental and health risks and impacts related to the mine's operation. Suspicions of environmental contamination are reinforced by accidents, mainly by past episodes of radioactive material leakages into the environment. So, in Caetité, it turns out ascenario of misinformation and uncertainty regarding the risks and impacts potentiallydue to the uranium mining and milling activities, which affect basically mineworkersand nearby rural communities. Classical technical and scientific approaches ofresearch and knowledge production appear limited to deal with situations that involvecomplex risks, especially in contexts of conflict and environmental injustices, just likethe case of Caetité's uranium mine operation. Thus, considering this setting, thisdissertation aims to make a critical reflection on the importance of alternativeknowledge production strategies, which value and incorporate the situatedknowledge of affected people in order to enable a better and contextualizedunderstanding of complex technological risks and its environmental and healthimplications. Therefore, it is taken as reference participatory and integratedknowledge production experiences about the risks and impacts related to uraniummining and milling in Caetité...

The interaction of natural background gamma radiation with depleted uranium micro-particles in the human body.

In this study, some characteristics of the photo-electrons produced when natural background gamma radiation interacts with micron-sized depleted uranium (DU) particles in the human body have been estimated using Monte Carlo simulations. In addition, an estimate has been made of the likelihood of radiological health effects occurring due to such an exposure. Upon exposure to naturally occurring background gamma radiation, DU particles in the body will produce an enhancement of the dose to the tissue in the immediate vicinity of the particles due to the photo-electric absorption of the radiation in the particle. In this study, the photo-electrons produced by a 10 µm-size particle embedded in tissue at the centre of the human torso have been investigated. The mean energies of the photo-electrons in the DU particle and in the two consecutive immediately surrounding 2 µm-wide tissue shells around the particle were found to be 38, 49 and 50 keV, respectively, with corresponding ranges of 1.3, 38 and 39 µm, respectively. The total photo-electron fluence-rates in the two consecutive 2 µm-wide tissue layers were found to be 14% and 7% of the fluence-rate in the DU particle, respectively. The estimated dose enhancement due to one 10 µm-sized DU particle in 1 cm(3) of tissue was less than 2 in 10 million of the dose received by the tissue without a particle being present. The increase in risk of death from cancer due to this effect is consequently insignificant.

Identification of health risks in workers staying and working on the terrains contaminated with depleted uranium.

This study investigated health risks in workers residing and working in terrains contaminated by low ionizing radiation doses which originated from ammunition containing depleted uranium (DU). The studied population was composed of two test groups (T-I, T-II) who were occasionally exposed to DU, and two referent (R-I, R-II) groups not exposed at any time to DU. All of them were evaluated for the following: complete clinical examination and blood count, presence of immature forms and blasts, leukocyte alkaline phosphatase activity and cytogenetic tests. The probability of onset of the characteristic complete biomarkers--chromosomal aberrations, was analyzed using logarithmic function of the Poisson regression. The estimated function of the density of probabilities of Poisson distribution of the chromosomal aberrations in the test group T-II was drastically different from the corresponding distribution of the referent group R-I and to a somewhat lesser extent from the group R-II; Wilcoxon test exactly confirms the presence of a significant difference between the reference group R-II and test group T-II, p < 0.05. The damages to chromosomes and cells were highest in the test group T-II of workers additionally occupationally exposed to DU. The group of workers T-I, who had been exposed to DU working on contaminated terrain, have had certain risks of cell and chromosome damages, and that risk was not greater than the risk to the referent group R-II of workers occupationally exposed to ionizing radiation.

Avaliação da incidência e mortalidade por câncer na população residente em região com anomalia geológica na ocorrência de urânio: estudo de caso: Monte Alegre, PA / Mortality and cancer incidence among residents in an area with a geological occurrence of uranium: the municipality of Monte Alegre, PA, Brazil

O município de Monte Alegre, PA apresenta níveis aumentados de radiação natural devido à presença de ocorrências uraníferas na região. Os objetivos dessa dissertação foram: realizar uma análise da evolução da mortalidade na população residente de Monte Alegre e compará-la com aquela observada nos municípios controles (Alenquer e Prainha); e determinar a ocorrência de neoplasia maligna no município de Monte Alegre a partir da avaliação do excesso de risco de mortalidade e das estimativas da incidência. A dissertação foi dividida em dois artigos, cada um atendendo a um dos objetivos. No primeiro foi avaliada a tendência temporal da mortalidade por todas as causas, causas mal definidas e neoplasias entre 1981 e 2005. Os dados utilizados foram os disponíveis no Sistema de Informação sobre Mortalidade (SIM). No segundo foram estimadas as Razões Padronizadas de Mortalidade (SMR), as razões de risco através da razão das SMRs de Monte Alegre e municípios controles e razões de chances de mortalidade por câncer (CMOR) para o município de Monte Alegre e controles no período de 1981 a 2005, utilizando a população do estado do Pará como referência. Para estimar a incidência de câncer foram realizadas três diferentes abordagens: a partir dos dados obtidos nos centros de diagnósticos para câncer que atendem a população da área de estudo; através dos dados de Autorização de Internação Hospitalar; e dados primários obtidos no inquérito populacional realizado na região em 2007/2008. Ao longo do período, observou-se um decréscimo da taxa padronizada de mortalidade geral em Monte Alegre por todas as causas assim como por causas mal definidas para ambos os sexos. Embora a tendência da mortalidade por neoplasias em Monte Alegre se apresente estável, a qualidade da base de dados de mortalidade não permite análises conclusivas da real situação deste grupo de causa de morte nos municípios analisados. Os valores de SMR para mortalidade por todas as causas, encontrados para Monte Alegre, foram similares aos dos municípios controles, apresentando redução estatisticamente significativa: SMRMA= 72,9, IC 95 por cento 70,5-75,3 e SMRMC=75,2, IC 95 por cento 76,2-77,3, respectivamente. Não se observou excesso de mortes por câncer em Monte Alegre e nos municípios controles, e a análise da mortalidade segundo sexo não revelou um excesso de risco estatisticamente significativo nas diferentes localizações tumorais. As diferentes abordagens para estimar a incidência de câncer em Monte Alegre apesar da precária qualidade dos dados não mostraram padrão distinto dos municípios controles. A inexistência de um registro de câncer de base populacional, no município de Monte Alegre, constitui-se em uma limitação importante para se conhecer a real incidência de câncer. No momento, pode-se afirmar que não há evidência científica que assegure um aumento das ocorrências de óbitos por neoplasias no município, sendo precipitado e especulativo concluir que a utilização das rochas de urânio estaria ocasionando um aumento na mortalidade por câncer na população de Monte Alegre.

Neutron-induced light-ion production from Fe, Pb and U at 96 MeV.

Double-differential cross-sections for light-ion production (up to A = 4) induced by 96 MeV neutrons have been measured for Fe, Pb and U. The experiments have been performed at The Svedberg Laboratory in Uppsala, using two independent devices, MEDLEY and SCANDAL. The recorded data cover a wide angular range (20 degrees -160 degrees ) with low energy thresholds. The data have been normalised to obtain cross-sections using np elastic scattering events. The latter have been recorded with the same setup, and results for this measurement are reported. The work was performed within the HINDAS collaboration with the primary aim of improving the database for three of the most important nuclei for incineration of nuclear waste with accelerator-driven systems. The obtained cross-section data are of particular interest for the understanding of the so-called pre-equilibrium stage in a nuclear reaction and will be compared with model calculations.

Uranyl sorption onto gibbsite studied by time-resolved laser-induced fluorescence spectroscopy (TRLFS).

Time-resolved laser-induced fluorescence spectroscopy (TRLFS) was combined with batch experiments to study the sorption of uranium(VI) onto gibbsite (gamma-Al(OH)3). The experiments were performed under ambient conditions in 0.1 M NaClO4 solution in the pH range from 5.0 to 8.5 using a total uranium concentration of 1x10(-5) M, and a solid concentration of 0.5 g/40 ml. Two uranyl surface species with fluorescence lifetimes of 330+/-115 and 5600+/-1640 ns, respectively, were identified. The first species was dominating the more acid pH region whereas the second one became gradually more prominent towards higher pH values. The fluorescence spectra of both adsorbed uranyl(VI) surface species were described with six characteristic fluorescence emission bands situated at 479.5+/-1.1, 497.4+/-0.8, 518.7+/-1.0, 541.6+/-0.7, 563.9+/-1.2, and 585.8+/-2.1 nm. The surface species with the short-lived fluorescence lifetime of 330 ns is attributed to a bidentate mononuclear inner-sphere surface complex in which the uranyl(VI) is bound to two reactive OH- groups at the broken edge linked to one Al. The second surface species with the significant longer fluorescence lifetime of 5600 ns was attributed to small sorbed clusters of polynuclear uranyl(VI) surface species. The longer fluorescence lifetime of the long-lived uranyl surface species at pH 8.5 is explained with the growing average size of the adsorbed polynuclear uranyl surface species.

A new method for separation of 131I, produced by irradiation of natural uranium.

Separation of 131I from natural uranium fission product mixtures has been accomplished by sorbing the 131I on special platinum-charcoal sorbent and desorbing by buffer solution (NaHCO3+Na2S2O3). High radiochemical and chemical purity is obtained by this method. Important parameters such as temperature, distillation rate, sorbing and desorbing rates and 131I separation yields have been investigated.

Report of the WHO Depleted Uranium Mission to Kosovo

It presents a background of the Mission, and information on the situation found in Kosovo, depleted uranium and titanium characteristics, Mission aproach, assessment of health information system and health of the population, and site assessment. Document in pdf format; Acrobat Reader required.

Surveillance of depleted uranium exposed Gulf War veterans: health effects observed in an enlarged "friendly fire" cohort.

To determine clinical health effects in a small group of US Gulf War veterans (n = 50) who were victims of depleted uranium (DU) "friendly fire," we performed periodic medical surveillance examinations. We obtained urine uranium determinations, clinical laboratory values, reproductive health measures, neurocognitive assessments, and genotoxicity measures. DU-exposed Gulf War veterans with retained metal shrapnel fragments were excreting elevated levels of urine uranium 8 years after their first exposure (range, 0.018 to 39.1 micrograms/g creatinine for DU-exposed Gulf War veterans with retained fragments vs 0.002 to 0.231 microgram/g creatinine in DU exposed but without fragments). The persistence of the elevated urine uranium suggests ongoing mobilization from the DU fragments and results in chronic systemic exposure. Clinical laboratory outcomes, including renal functioning, were essentially normal. Neurocognitive measures showing subtle differences between high and low uranium exposure groups, seen previously, have since diminished. Sister chromatid exchange frequency, a measure of mutation in peripheral lymphocytes, was related to urine uranium level (6.35 sister chromatid exchanges/cell in the high uranium exposure group vs 5.52 sister chromatid exchanges/cell in the low uranium exposure group; P = 0.03). Observed health effects were related to subtle but biologically plausible perturbations in central nervous system function and a general measure of mutagen exposure. The findings related to uranium's chemical rather than radiologic toxicity. Observations in this group of veterans prompt speculation about the health effects of DU in other exposure scenarios.

[Malignant neoformations of the hematopoietic and lymphoid tissues in the personnel of the 1st plant of atomic industry]. / Zlokachestvennye novoobrazovaniia krovetvornoi i limfaticheskoi tkanei u personala pervogo predpriiatiia atomnoi promyshlennosti.

Rates of mortality from hemopoietic and lymphoid malignancies for 1948-1987 were studied in male staff of industrial atomic reactors and radiochemical industry for irradiated uranium processing versus dose of external gamma radiation. An increase in mortality due to radiation--induced acute leukemia was registered in the radiochemical industry staff 5-10 years following the start of exposure and was associated with high dose of external radiation. The risk of acute leukemia for this period was 1.65 x 10(-3) x Sv-1 cases during 5 years whereas within the other 30-35 years of follow-up the risk of death from hemolymphoblastosis or acute leukemia was less than 1 x 10(-3) x Sv(-1) during 5 years.