[en] Published in summary form only

[en] The Brazilian Safeguards Analytical Laboratory, inaugurated in September 1983, performs uranium analysis in samples of nuclear materials taken during safeguards inspections as well as in samples taken during ABACC's inspections performed in Argentina. The Laboratory analyzes intercomparison samples provided by IAEA, NBL, ABACC, CEN and EQRAIN. The method used to perform uranium analysis is the Davis and Gray/NBL. All the steps of the analytical procedures, such as chemical kinetics of the reactions and instrumental parameters, are rigorously controlled. An internal Quality Control of the Measurements is made by means of analysis of Certified Reference Materials and the performance of the results meets the ESARDA's Target Values for Random and Systematic components both in intercomparison samples and in samples taken during inspections. The typical precision, expressed as relative standard deviation, and the accuracy obtained in a routine basis for nuclear grade materials is 0.1% and 0.14% respectively. The performance of the results obtained are comparable to the best international laboratories which perform uranium analysis in nuclear material for safeguards purposes. (author)

[en] Full text: The Brazilian Safeguards Analytical Laboratory, inaugurated in September 1983, performs uranium analysis in samples of nuclear materials taken during national safeguards inspections as well as in samples taken during ABACC's inspections performed in Argentina. The Laboratory analyzes Intercomparison samples provided by IAEA, NBL, ABACC, CEN and EQRAIN. The method used to perform uranium analysis is the Davies and Gray/NBL. All the steps of the analytical procedures, such as chemical kinetics of the reactions and instrumental parameters, are rigorously controlled. An internal Quality Control of the measurements is made by means of analysis of Certified Reference Materials and the performance of the results meets the ESARDA's Target Values for Random and Systematic Components both in Intercomparison Samples and in samples taken during inspections. The typical precision, expressed as relative standard deviation, and accuracy obtained in a routine basis for nuclear grade materials is 0.1% and 0.14% respectively. The performance of the results obtained are comparable to the best international laboratories which perform uranium analysis in nuclear materials for safeguards purposes. (author)

No abstract available

[en] Values of the order of 10⁴ to 10⁵ Bq/Kg for the Cs-137 specific activity were observed for soils from regions within a radius of about 50 meters around the main focus. The dissemination was done by the wind and further deposition. However, it was also observed the disposal of contaminated housewaste at unused gardens nearby. It was found the soil profiles as an adequated method for decision on the soil layer to be removed. The in-soil Cs-137 migration presented the same shape whatever the specific activity deposited at the surface and in average 30% of the total activity has remained at the upper 1.5 cm layer over the first five months after the accident. The limits and procedures that have been adopted ensure a total dose to the critical group below 4 mSv for the first year and 0.68 mSv/a in average over the life-time above background. (author)

[en] This work presents ²¹⁰ Pb geochronology of five bottom sediment cores from flood plain lakes of middle Taquari River, Pantanal, MS. In two cores of a same lake, an increase of the sediment deposition rate were observed, reflecting an increasing of the sediment input to the Pantanal. The main causes suggested for this increasing are climatic change, and the development of agriculture and cattle-raising in the watershed highlands, for the last 25 years. The results pointed too for the importance of a additional sample in the superior region of the middle Taquari River. (author)