Nuclear activation methods for the characterization of fossil fuels

A review is presented on the use of neutron activation analysis (NAA) for the analyses of coal, oil shale, tar sands and petroleum. Fast NAA has been widely used for the determination of oxygen, and to a limited extent, of other elements such as nitrogen and silicon. Reactor NAA followed by instrumental counting, and in specific cases, after radiochemical separations is discussed. Thermal and epithermal neutrons are both used. Limited use of the 252Cf source has been made in fuel analysis. A complementary technique to NAA is the photon activation analysis with linear accelerator. It can determine over thirty elements, many of them not possible to do by NAA. Round-robin analyses of standard coal, fly ash, or oil shale samples indicate that nuclear activation methods are comparable in accuracy and precision to X-ray fluorescence or atomic spectrometric methods for most elements. (author)