This guide is applicable to samples containing 2 to 10 % gadolinium oxide and 90 to 98 % uranium oxide on the “as received” basis. The method may be used to determine concentration of either uranium, gadolinium, or both.

Either wavelength-dispersive or energy-dispersive x-ray fluorescence systems may be used provided the software accompanying the system is able to accommodate the use of internal standards.

1.1 This standard describes the steps necessary for the preparation and analysis by X-ray fluorescence (XRF) of gadolinium and/or uranium in gadolinium oxide-uranium oxide pellets or powders.

1.2 This method requires the use of appropriate internal standard(s). Care must be taken to ascertain that samples analyzed by this method do not contain the internal standard element(s) or that this contamination has been corrected for mathematically whenever present. Such corrections are not addressed in this standard.

This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific precautions are given in Section and various notes throughout the method.