The radioactivity content of United Kingdom coal

Characterization of coal and charcoal by alpha-particle and gamma-ray spectrometry

“…Then 236 U and 229 Th yield tracers were added, and the solution was dried. This procedure is based on the work of Salmon et al (1984).…”

“…One observes that, in general, the ranges found in the present work for the activity concentrations of 238 U, 232 Th, 228 Ra, 226 Ra, and 40 K in the two coal samples are within the literature ranges. The values listed as reported by other authors for the 238 U and 232 Th series isotopes were obtained by gamma-ray spectrometry, except for Salmon et al (1984) who determined their 238 U, 234 U, 232 Th, and 230 Th activity concentrations by alpha-particle spectrometry. Finally, as a check of the experimental procedures proposed in the present work, one notes the coincidence in value of the 228 Th activity concentrations determined by alpha-particle and gammaray spectrometry, considering a 2s uncertainty interval, for the samples with concentrations above the corresponding MDA.…”

“…However, the determination of uranium isotope concentrations by gamma-ray spectrometry is only possible if secular equilibrium can be assumed. If this is not the case, alpha-particle spectrometry must be used (Salmon et al, 1984). In the present work, we shall describe procedures based on both gamma-ray and alpha-particle spectrometry, and analyze several coal and charcoal samples.…”

Evaluation of two radiochemical procedures for the determination of uranium and thorium isotopes in coal samples

“…Finally, 20-40 mL HNO 3 (65 %) was added, and the mixture was again dried. The procedure followed was based on that proposed by Salmon et al [12]. The residue was conditioned in 40 mL 8 M HNO 3 .…”

“…Total dissolution of the coal is essential for the quantification of these elements because they can form associations with both the organic and the inorganic matter content [11]. The literature describes methods based on acid leaching the sample to determine its uranium and thorium activity concentrations by alpha-particle spectrometry [12]. The microwave digestion technique is suitable for determination of trace elements in coals by mass spectrometry [11,13], although the use of HF can cause problems with this technique [14].…”