ISO 16796-2022 pdf free download – Nuclear energy — Determination of Gd 2 O 3 content in gadolinium fuel blends and gadolinium fuel pellets by atomic emission spectrometry using an inductively coupled plasma source (ICP-AES).
8.1.7 Dilute to 100 ml with demineralized water.
8.2Preparation of the powder test samples of Gdz03 plus Uoz
8.2.1 Weigh 5,0 g of test sample into a beaker, weighed to the nearest 0,001 g.
8.2.2 Prepare the test sample as described in 8.1, steps
8.1.2 through 8.1.7.8.3Preparation of pellet standards and test samples
8.3.1 Crush the pellet using a percussion mortar (5.8).
8.3.2 Weigh 5,0 g into a crucible, weighed to the nearest 0,001 g.
8.3.3 Heat the crucible with the test sample in a muffle furnace at 420 °C± 25 °C minimum for 2 h to3 h.
8.3.4Quantitatively transfer the content from the crucible to a glass beaker. Then proceed asdescribed in 8.1,steps 8.1.2 through 8.1.7.
9 Calibration and analysis of test samples9.1General
Standards as prepared in Clause 7 and 8.1 are used to calibrate the equipment.
Calibration standards shall be traceable to the Sl and shall bracket the anticipated concentration rangefor the dissolved test samples being measured.
a) In the event that a test sample result is outside of the calibration range: the instrument shallbe recalibrated and the measurements repeated; or the test sample dilution scheme shall be
adjusted so the concentration of the dissolved test sample is within the calibration range when themeasurement is repeated.
b)Independence between reference materials used to prepare calibration standards and quality
control standards is required.At a minimum, different lots of gadolinium reference material fromthe same supplier may be used to prepare calibration and quality control standards,however usingdifferent suppliers is recommended.
9.2Calibration
The measurement system shall be calibrated using traceable reference materials procured fromcompetent and qualified suppliers.
The ICP-AES analytical conditions are developed by each laboratory.
– Instrument wavelength calibration, camera alignment, and tuning shall be performed in accordance
with manufacturer’s guidance.
Optical intensity and plasma position should be verified as part of the calibration process,inaccordance with manufacturer’s guidance.
No specific intensity is required other than that it should not change significantly from the lastseries of analyses.
The measurement of optical intensity is typically performed each day at a single wavelength usingthe same concentration analyte (for example 10 ug/g manganese standard solution at 257,610 nm).The intensity is normally measured radially with respect to the plasma.Gadolinium measurementsat high concentration are typically measured radially while low concentration gadolinium istypically measured axially.
To calibrate the measurement system for powder test samples, the standard solutions prepared inaccordance with 8.1 are measured in at least duplicate and the calibration curve produced from theintensity-versus-concentration curve.
To calibrate the measurement system for pellet test samples, the standard solutions prepared inaccordance with 8.3 are measured in at least duplicate and the calibration curve produced from theintensity-versus-concentration curve.
Calibration curves are evaluated using acceptance criteria established by each laboratory, based upontheir historical performance; e.g., linear regression fit(R2), slope, and coefficient of error.
See example in Annex A.
9.3Analysis of the test samples and quality control standards
The test samples prepared in 8.2 and 8.3 shall be analysed after making the calibration curve.Testsamples shali be measured in at least duplicate and spiked test samples should be measured at adefined frequency such as one test sample per batch of ten or fewer similar test samples.To avoid dailycorrection and achieve the required precision, a new calibration curve is prepared for each batch of testsample determinations.
Process blank measurements should be performed periodically to ensure that background levels are inthe expected range; however, background corrections are not normally necessary.
Quality control (Qc) standards shall be prepared and measured in the same manner as test samples.Compare the emission intensities of the test samples and QC standards to the calibration curve andcalculate the Gd,0, concentrations for each of the test samples and QC standards.ISO 16796 pdf download.