Inorganic , Ores
Both, IAEA-RGU-1 and IAEA-RGTh-1 reference materials were prepared on behalf of the International Atomic Energy Agency by the Canada Centre for Mineral and Energy Technology by dilution of a uranium ore BL-5 (7.09% U) and a thorium ore OKA-2 (2.89% Th, 219 μg U/g) with floated silica powder of similar grain size distribution, respectively. No evidence for between-bottles inhomogeneity was detected after mixing and bottling. BL-5 has been certified for uranium, 226Ra and 210Pb confirming that it is in radioactive equilibrium. The agreement between radiometric and chemical measurements of thorium and uranium in OKA-2 shows both series to be in radioactive equilibrium.
|232Th||3250?||Bq/kg||3160 - 3340||155||R|
|235U||3.6?||Bq/kg||3.3 - 3.9||145||R|
|238U||78?||Bq/kg||72 - 84||145||R|
|40K||6.3?||Bq/kg||3.1 - 9.5||45||I|
|K||200||mg/kg||100 - 300||45||I|
|Th||800||mg/kg||784 - 816||155||R|
|U||6.3||mg/kg||5.9 - 6.7||145||R|
(Value) Concentration calculated as a mean of the accepted laboratory means (N) Number of accepted laboratory means which are used to calculate the recommended or information values and their respective confidence intervals (R/I/C) Classification assigned to the property value for analyte (Recommended/Information/Certified) (?) Natural radionuclide activity concentrations derived from the elemental concentrations on basis of isotopic abundance and half-life data
The values listed above were established on the basis of a gravimetric dilution of materials with known uranium, thorium and potassium composition. The details concerning the criteria for qualification as a recommended or information value can be found in the respective report (attached).