ISO 12183:2024
(Main)Nuclear fuel technology — Controlled-potential coulometric measurement of plutonium
Nuclear fuel technology — Controlled-potential coulometric measurement of plutonium
This document specifies an analytical method for the electrochemical measurement of pure plutonium nitrate solutions of nuclear grade, with an expanded uncertainty not exceeding ±0,2 % at the confidence level of 0,95 for a single determination (coverage factor, k = 2). The method is applicable for aqueous solutions containing plutonium at more than 0,5 g/l and test samples containing plutonium between 4 mg and 15 mg. Application of this technique to solutions containing plutonium at less than 0,5 g/l and test samples containing plutonium at less than 4 mg requires experimental demonstration by the user that applicable data quality objectives will be met.
Technologie du combustible nucléaire — Dosage du plutonium par coulométrie à potentiel imposé
Le présent document spécifie une méthode analytique pour le dosage électrochimique de plutonium pur dans des solutions nitriques de qualité nucléaire, avec une incertitude ne dépassant pas ±0,2 % dans un intervalle de confiance de 0,95 pour une simple détermination (facteur d'élargissement, k = 2). La méthode est applicable aux solutions aqueuses contenant plus de 0,5 g/L de plutonium et à des échantillons pour essai contenant entre 4 mg et 15 mg de plutonium. L'application de cette technique aux solutions contenant moins de 0,5 g/l de plutonium et à des échantillons pour essai contenant moins de 4 mg de plutonium exige que l'utilisateur démontre expérimentalement que les objectifs relatifs aux exigences qualités applicables soient atteints.
General Information
Relations
Standards Content (Sample)
International
Standard
ISO 12183
Fourth edition
Nuclear fuel technology —
2024-05
Controlled-potential coulometric
measurement of plutonium
Technologie du combustible nucléaire — Dosage du plutonium
par coulométrie à potentiel imposé
Reference number
© ISO 2024
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Reagents . 2
6 Apparatus . 2
7 Procedure . 8
7.1 Plutonium determination .8
7.2 Analysis of subsequent test samples . .14
8 Expression of quantity values . 14
8.1 Calculation of the electrical calibration factor .14
8.2 Calculation of the blank . 15
8.3 Fraction of electrolysed plutonium . 15
8.4 Plutonium, amount of substance and mass .16
8.5 Quality control .16
9 Characteristics of the method . 17
9.1 Repeatability .17
9.2 Confidence interval .17
9.3 Analysis time .17
10 Interferences . 17
11 Procedure variations and optimization .21
11.1 Accountability measurements and reference material preparation .21
11.2 Process control measurements .21
11.3 Measurement cell design . 22
11.4 Electrolyte and electrode options . 22
11.5 Test sample size . 22
11.6 Background current corrections . 23
11.7 Correction for iron . 23
11.8 Control-potential adjustment .24
11.9 Calibration methodologies . 25
12 Traceability to SI units .25
Annex A (informative) Purification by anion-exchange separation .26
Annex B (informative) Determination of formal potential, E .28
Bibliography .29
iii
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.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 85, Nuclear energy, nuclear technologies, and
radiological protection, Subcommittee SC 5, Nuclear fuel cycle, in collaboration with the European Committee
for Standardization (CEN) Technical Committee CEN/TC 430, Nuclear energy, in accordance with the
Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
This fourth edition cancels and replaces the third edition (ISO 12183:2016), which has been technically
revised.
The main changes are as follows:
— Figures 1 and 2 have been revised to resolve errors introduced in the third edition of this document;
— quantity values and uncertainties values have been reformatted to comply with requirements for
properly stating these values with SI units;
— editorial changes were made throughout the document to ensure clarity of the instructions;
— words with optional spellings were corrected to match ISO/IEC guidance;
— an additional key step was added to Clause 4 to indicated that the moles of plutonium obtained by
controlled-potential coulometry is multiplied by the molar mass of plutonium obtained by other means,
such as mass spectrometry or process knowledge;
— a formula has been added to 8.4 to calculate the amount of substance of plutonium in millimoles in
addition to the mass of plutonium in milligrams;
— Clause 12 has been added to discuss traceability to SI units.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
International Standard ISO 12183:2024(en)
Nuclear fuel technology — Controlled-potential coulometric
measurement of plutonium
1 Scope
This document specifies an analytical method for the electrochemical measurement of pure plutonium
nitrate solutions of nuclear grade, with an expanded uncertainty not exceeding ±0,2 % at the confidence
level of 0,95 for a single determination (coverage factor, k = 2). The method is applicable for aqueous solutions
containing plutonium at more than 0,5 g/l and test samples containing plutonium between 4 mg and
15 mg. Application of this technique to solutions containing plutonium at less than 0,5 g/l and test samples
containing plutonium at less than 4 mg requires experimental demonstration by the user that applicable
data quality objectives will be met.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
4 Principle
The key steps and their purposes are outlined below:
— test samples are prepared from homogenous solutions by weighing and then fuming to dryness with
sulfuric acid to achieve a stable anhydrous plutonium sulfate salt that is free from chloride, fluoride,
nitrate, nitrite, hydroxylamine, and volatile organic compounds;
— if needed to remove interferences, dissolve test samples and purify by anion exchange, then fume the
eluted plutonium solution in the presence of sulfuric acid to obtain the anhydrous plutonium sulfate salt;
— measure the supporting electrolyte blank and calculate the background current correction applicable to
[1]
the electrolysis of the test sample from charging, faradaic, and residual currents ;
— dissolve the dried test sample in the previously measured supporting electrolyte (the blank);
3+
— reduce the test sample at a controlled potential that electrolyses the plutonium to a Pu amount of
substance fraction greater than 99,8 % and measure the equilibrium solution potential at the end of this
[2]
step by control-potential adjustment ;
4+
— oxidize the test sample at a controlled potential that electrolyses the plutonium to a Pu amount fraction
greater than 99,8 % and measure the equilibrium solution potential at the end of this electrolysis by
control-potential adjustment;
— correct the integrated current (integrator output from the test sample) for the background current,
including the residual current corrections, and for the amount f
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.