Quantitative analysis of uranium, thorium and potassium from lignite ash by neutron activation method

Quantitative analysis of uranium, thorium and potassium from lignite ash is determined by Neutron Activation (NA) Method, using the samples of fly ash and bottom ash from Krabi and Mae Moh power plants. The analysis has been performed since 1981. The result obtained by this method during 1981 and 1983 shows that the quantities of U, Th and K in Krabi are higher than that of Mae Moh lignite ash. Krabi lignite is composed of 132.9+.30.42 ppm of low-grade U-fly ash and 124.6+.32.69 ppm of low-grade U-bottom ash; 37.41+.15.16 ppm of Th-fly ash and 32.947+.6.53 ppm of Th-bottom ash; 1.658+.0.374% of K-fly ash and 1.616+.0.403% of K-bottom ash. Compared with the data obtained by the International Atomic Energy Agency (IAEA), its range appears to be interesting and promising