ISO 7097-2:2004 核燃料技術—溶液中のウラン、六フッ化ウランおよび固体の測定—パート2：鉄（II）還元/セリウム（IV）酸化滴定法 | ページ 2

Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be 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.

International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, 2.

The main task of technical committees is to prepare International Standards. 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.

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 7097-2 was prepared by Technical Committee ISO/TC 85, Nuclear energy, Subcommittee SC 5, Nuclear fuel technology.

This first edition of ISO 7097-2, together with ISO 7097-1:2004, cancels and replaces ISO 7097:1983, which has been technically revised, and ISO 9989:1996.

ISO 7097 consists of the following parts, under the general title: Nuclear fuel technology — Determination of uranium in solutions, uranium hexafluoride and solids:

Part 1: Iron(II) reduction/potassium dichromate oxidation titrimetric method

Part 2: Iron(II) reduction/cerium(IV) oxidation titrimetric method

Introduction

This part of ISO 7097 describes procedures for determination of uranium in solutions, uranium hexafluoride and solids. The procedures described in the two independent parts of this International Standard are similar: this part uses a titration with cerium(IV) and ISO 7097-1 uses a titration with potassium dichromate.

1 Scope

This part of ISO 7097 describes an analytical method for the determination of uranium in pure product material samples such as U metal, UO₂, UO₃, uranyl nitrate hexahydrate, uranium hexafluoride and U₃O₈ from the nuclear fuel cycle. This procedure is sufficiently accurate and precise to be used for nuclear materials accountability.

This method does not generate a toxic mixed waste as does the potassium dichromate titration. The method may not be applied to scrap or waste samples until such time as it is qualified by obtaining results statistically equivalent to those obtained by the potassium dichromate method on the same sample types.

The method recommends that an aliquot of sample is weighed and that a mass titration is used, in order to obtain improved precision and accuracy. This does not preclude the use of any alternative techniques which could give equivalent performance. As the performance of some steps of the method is critical, the use of some automatic device has some advantages, mainly in the case of routine analysis.

2 Normative references

The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

Bibliography