Technetium measurements by accelerator mass spectrometry at LLNL

[摘要] Technetium-99 is a long-lived, high-abundance fission product which has been widely distributed in the environment through atmospheric testing, the nuclear fuel cycle, and nuclear medicine. It has a high potential for migration in the environment as the pertechnetate anion. At the Center for Accelerator Mass Spectrometry, methods are being developed for the detection of this radionuclide by accelerator mass spectrometry (AMS), including extraction from environmental samples, concentration and purification of the Tc-99, conversion to a form appropriate for AMS analysis, and quantification by AMS. Besides interference from the stable (though relatively rare) atomic isobar Ru-99, the detection of Tc-99 by AMS presents some technical challenges which are not present for the other radionuclides typically measured by AMS. These challenges are related to the lack of a stable Tc isotope. Here we present the status of our Tc-99 methods including discussion of interferences and sensitivity, and recent results for environmental samples and the IAEA reference material IAEA-381, Irish Sea Water. Sensitivity is presently similar to 10 mu Bq (similar to 1 x 10(8) atoms) per sample, limited primarily by 99Ru introduced from process chemicals, and precision/reproducibility is similar to 15-25%. (C) 2000 Elsevier Science B.V. All rights reserved.

[发布日期] 2000-10-01

[效力级别]  Proceedings Paper

[关键词] technetium;Tc-99;niobium;peroxoniobium;fission products;radiochemistry;trace detection;accelerator mass spectrometry (AMS)