ISO INTERNATIONAL STANDARD 9891 First edition 1994-12-15 Determination of carbon content in uranium dioxide powder and sintered pellets High-frequency induction furnace combustion Titrimetric/coulometric/infrared absorption methods frittees de dioxyde d'uranium -Combustion dans un four électriquea induction -Methodes par titrimetrie/coulométrie/absorptiométrie infrarouge ISO Reference number ISO 9891 1994(E) No reproduction or networking permitted without license from IHS Not for Resale ISO9891:1994(E) Foreword IsO (the International Organization for Standardization) is a worldwide federation of national standards bodies (lsO member bodies). The work of preparing International Standards is normally carried out through isO technical committees. Each member body interested in a subject for represented on that committee. International organizations, governmental and 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. Draft International Standards 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. International Standard ISO 9891 1 was prepared by Technical Committee ISO/TC 85, Nuclear energy,. Subcommittee SC 5, Nuclear fuel technology. ISO 1994 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced microfilm, without permission in writing from the publisher. International Organization for Standardization CasePostale56·CH-1211Geneve20·Switzeriand Printed in Switzerland ii Copyight intematinal Organization for Standardizalion No reproduction or networking permitted without license from IHS Not for Resale INTERNATIONAL STANDARD ISO ISO9891:1994(E) Determination of carbon content in uranium dioxide powder and sintered pellets -- High-frequency induction furnace combustion Titrimetric/coulometric/infrared absorption methods 1 Scope 3Reaction This International Standard specifies titrimetric/ CO2 + H2O + Ba(CIO42 → BaCO3 + 2H+ + 2CIO4 calometric/infrared absorption methods for determin ing the carbon content in uranium dioxide powder and 4 Reagents and materials sintered pellets, the test sample being heated in an inductionfurnace. During the analyses, unless otherwise stated, use only reagents of recognized analytical grade and only It is applicable to the determination of 5 μg to 500 μg distilled water or water of equivalent purity. of carbon in uranium dioxide powder and pellets. In- terference from sulfur and halogens is prevented by 4.1 Oxygen, of commercial grade, better than the use of appropriate traps. 99,9 % (V/M) purity. 4.2 Carbon dioxide, commercial grade, better than 99,9 % (V/V) purity. 2 Principle 4.3 Copper oxide, 1 mm to 2 mm granules. A portion of the test sample is heated at a temper- ature of at least 1 100 °C to 1 200 °C in a quartz- encapsulated tungsten crucible or in a platinum 4.4 Soda lime, of the self indicating type, 1 mm to crucible, in an oxygen atmosphere. The evolved 2 mm granules. oxidation products are passed over a purification trap, filled with manganese dioxide and silver permanga- 4.5 Molecular sieve 4A, 1,6 mm (1/16 in) pellets, nate catalyst. Manganese dioxide absorbs nitrogen preheated at 300 °C. oxides. Silver permanganate catalyst will oxidise car- bon monoxide to carbon dioxide and absorb sulfur 4.6 Silver permanganate catalyst (in Europe avail- oxides and halogens. able as Korbl's combustion catalyst). for element analysis. The carbon dioxide is trapped in an absorption solution of barium perchlorate, adjusted to pH = 10,0. Ab- 4.7 Manganese dioxide, activated, combustion sorption of carbondioxidecausesa decreaseofthe analysis grade, 0,5 mm to 1,5 mm granules. pH. The initial pH is restored continuously by the ad- dition of hydroxyl ions either by potentios