ISO INTERNATIONAL STANDARD 16424 Firstedition 2012-12-01 Nuclear energy - Evaluation of homogeneity of Gd distribution within gadolinium fuel blends and determination of Gd2O3 content in gadolinium fuel pellets by measurements of uranium and gadolinium elements Energie nucleaire -Evaluation de I'homogeneite de la distribution du Gd dans les melanges de combustibles augadolinium et détermination dela teneuren Gd2O3dans lespastilles combustibles au gadolinium par mesurage des élements uranium et gadolinium Reference number IS016424:2012(E) LSO Copyright International Organization for Standardization @IS02012 cense from IHS Not for Resale IS0 16424:2012(E) COPYRIGHTPROTECTEDDOCUMENT ISO2012 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either IsO at the addressbeloworIso'smemberbodyinthecountryoftherequester. ISO copyright office Casepostale56.CH-1211Geneva20 Tel. + 41 22 749 0111 Fax +412274909 47 E-mail [email protected] Web www.iso.org Published in Switzerland @ IS0 2012 - All rights reserved No reproduction or r networking permited without license from IHS Not for Resale IS016424:2012(E) Contents Page Foreword ..iv 1 Scope. .1 2 Normativereferences .1 3 Principle. 4 Apparatus .2 4.1 Highdispersion directreadingICP-AES .2 4.2 Analytical balance. .2 4.3 Smallstainlesssteelspoon .2 5 Reagents .2 6 Referencesolutions .2 6.1 Gadoliniumelementreferencesolutions .2 6.2 Uranium elementreference solutions .3 7 Samplepreparation. .3 7.1 Sample preparation for evaluation of Gd homogeneity in gadolinium fuel blend .3 7.2 SamplepreparationfordeterminingtheGd2O3contentofGdfuelpellets .3 8 Calibration and analysis ofthe samples .3 .3 8.1 CalibrationofGdpeaklineintensity 8.2 Calibration of U peak line intensity .3 8.3 Evaluationof Gdhomogeneity ingadoliniumfuelblend ..3 8.4 Determination of Gd2O3 content in gadolinium fuel pellet .4 9 Precision ..6 10 Test report .6 Annex A (informative) Calibration and Gd and U measurement uncertainties .7 AnnexB(informative)Derivationofo/Mando/Uratioformulas .10 AnnexC (informative)Evaluation of Gd2O3 measurement precision .12 Bibliography .15 iii t license from IHS Not for Resale