ISO INTERNATIONAL STANDARD 18213-3 First edition 2009-03-01 Nuclear fuel technology Tank calibration and volume determination for nuclear materials accountancy Part 3: Statistical methods Technologie du combustible nucleaire- Etalonnage et determination duvolumede cuvepourla comptabilitedes matieres nucleaires Partie 3: Methodes statistiques Reference number ISO 18213-3:2009(E) @ISO2009 nal Organization for Standardizatior No reproduction or networking permited without icense from IHS Not for Resale ISO 18213-3:2009(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by IsO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. COPYRIGHTPROTECTEDDOCUMENT @ISO2009 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means. ISO's member body in the country of the requester. ISO copyright office Case postale 56: CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail [email protected] Web www.iso.org Published in Switzerland @ Is0 2009 - All rights reserved CyhtlanzoStandardzato No reproduction or networking pemitted without license from IHS Not for Resale ISO18213-3:2009(E) Contents Page Foreword iv Introduction Scope 1 2 Normative references 3 Table of symbols. 2 4 Data required . 5 Diagnostic plots 5.1 Overview. 5.2 Calibration data... 5.3 Auxiliary data 1 6 Uncertaintyestimation for calibration data 6.1 Measurement system response (height).... 12 6.2 Measurements oftank content (volume,mass) 7 Estimation of themeasurement equationandassociateduncertainties 14 7.1 Preliminaries .... 14 7.2 Measurement model 15 7.3 Estimationofmodelparameters 19 7.4 Volume determinations and variance estimates. 22 7.5 Confidence regions and prediction intervals. 23 8 Uncertainty estimates for volume determinations .28 8.1 28 8.2 Containedvolumes 28 8.3 Transfer volumes . 32 AnnexA (informative)Examples ofdiagnosticplots.. Annex B (informative) Welch-Satterthwaite equation for computing degrees of freedom... Annex C (informative)Target uncertainty limits formeasurements associated withtank calibration and volume determination.... 43 Bibliography .. Standardizationrights reserved ili No reproduction or networking pemitted without license from IHS Not for Resale ISO 18213-3:2009(E) Foreword iSO (the InternationalOrganizationfor Standardization)is a worldwidefederationofnational standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. IsO shall not be held responsible for identifying any or all such patent rights. ISO