ISO 23468:2021

INTERNATIONAL ISO
STANDARD 23468
First edition
2021-08
Reactor technology — Power reactor
analyses and measurements —
Determination of heavy water isotopic
purity by Fourier transform infrared
spectroscopy
Technologie du réacteur — Analyses et mesurages relatifs aux
réacteurs de puissance — Détermination de la pureté isotopique de
l’eau lourde par spectroscopie infrarouge à transformée de Fourier
Reference number
©
ISO 2021
© ISO 2021
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ii © ISO 2021 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Reagents and materials . 3
6 Apparatus . 3
7 Heavy water reference standard preparation . 4
7.1 General requirements . 4
7.2 Storage of high isotopic purity heavy water reference standard. 4
7.2.1 Ampoule bottle . 4
7.2.2 Specially designed stainless steel container . 4
7.3 Lower D O concentration reference standard preparation . 4
8 Sampling . 5
8.1 General requirements . 5
8.2 Sampling with syringes . 5
8.3 Sampling with bottles . 5
9 Preparation of calibration curves of the method . 5
9.1 General . 5
9.2 Preparation of the apparatus . 6
9.2.1 FTIR spectrometer . 6
9.2.2 Infrared liquid cell . 7
9.3 Editing of the method . 7
9.4 Background spectrum . 7
9.5 Heavy water reference standard spectra . 7
9.6 Draw the calibration curves for different D O concentration ranges . 7
10 Procedure. 8
10.1 Sample preparation . 8
10.1.1 Sample temperature adjustment . 8
10.1.2 Sample filtration . 8
10.1.3 Sample source check . 8
10.2 Sample load and scan . 8
10.3 After measurement . 8
11 Expression of results . 9
11.1 Calculation method . 9
11.2 Precision . 9
11.3 Uncertainty .10
12 Interferences .10
12.1 Contaminated samples .10
12.2 Air bubbles .10
12.3 Foreign materials on the outside of the cell window .11
13 Test report .11
Annex A (informative) Specially designed stainless steel container for D O reference standard .12
Annex B (informative) Interested region suggested for typical curves .14
Bibliography .19
Foreword
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iv © ISO 2021 – All rights reserved

INTERNATIONAL STANDARD ISO 23468:2021(E)
Reactor technology — Power reactor analyses and
measurements — Determination of heavy water isotopic
purity by Fourier transform infrared spectroscopy
1 Scope
This document specifies an analytical method for determining heavy water isotopic purity by Fourier
transform infrared spectroscopy (FTIR). It is applicable to the determination of the whole range of
heavy water concentration. The method is devoted to process controls at the different steps of the
process systems in heavy water reactor power plant or any other related areas.
The method can be applied for heavy water isotopic purity measurements in a heavy water reactor
power plant or research reactor, heavy water production factory and heavy water related areas.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
ISO 3696, Water for analytical laboratory use — Specification and test methods
3 Terms and definitions
For the purposes of this document, the following terms and definitions are applied.
ISO and IEC maintain terminological 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/
3.1
heavy water
water which contains a higher than normal proportion of the heavy isotopes of hydrogen in combination
with oxygen
Note 1 to entry: HDO exists whenever there is water with hydrogen-1 and deuterium in the mix. HDO is formed
when hydrogen and deuterium atoms are rapidly exchanged between light water and heavy water molecules.
Note 2 to entry: Heavy water here does not mean “heavy water” which is enriched in the heavier oxygen isotopes
17 18
O and O.
Note 3 to entry: The ice point of heavy water is as high as 3,8 °C, care should be taken to avoid heavy water from
freezing.
[SOURCE: ISO 6107:2021, 3.272, modified — Notes 1 to 3 to entry were added.]
3.2
light water
water that contains natural abundance of protium and deuterium
3.3
Fourier transform infrared spectroscopy
FTIR
method in which a sample is subjected to excitation of molecular bonds by pulsed, broad-band infra-red
radiation and the Fourier transform mathematica
...