FprEN ISO 22765

SLOVENSKI STANDARD
oSIST prEN ISO 22765:2024
01-februar-2024
Tehnologija jedrskih goriv - Sintrani peleti (U, Pu)O2 - Navodilo za pripravo
keramografske preiskave mikrostrukture (ISO/DIS 22765:2023)
Nuclear fuel technology - Sintered (U,Pu)O2 pellets - Guidance for ceramographic
preparation for microstructure examination (ISO/DIS 22765:2023)
Kernbrennstofftechnologie - Gesinterte (U,Pu)O¿-Pellets - Leitfaden für die
keramographische Herstellung der Proben zur Untersuchung des Feingefüges (ISO/DIS
22765:2023)
Technologie du combustible nucléaire - Pastilles (U,Pu)O2 frittées - Préconisations
relatives à la préparation céramographique pour examen de la microstructure (ISO/DIS
22765:2023)
Ta slovenski standard je istoveten z: prEN ISO 22765
ICS:
27.120.30 Cepljivi materiali in jedrska Fissile materials and nuclear
gorivna tehnologija fuel technology
oSIST prEN ISO 22765:2024 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN ISO 22765:2024
oSIST prEN ISO 22765:2024
DRAFT INTERNATIONAL STANDARD
ISO/DIS 22765
ISO/TC 85/SC 5 Secretariat: BSI
Voting begins on: Voting terminates on:
2023-12-19 2024-03-12
Nuclear fuel technology — Sintered (U,Pu)O2 pellets
— Guidance for ceramographic preparation for
microstructure examination
Technologie du combustible nucléaire — Pastilles (U,Pu)O2 frittées — Préconisations relatives à la
préparation céramographique pour examen de la microstructure
ICS: 27.120.30
This document is circulated as received from the committee secretariat.
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
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NATIONAL REGULATIONS.
ISO/DIS 22765:2023(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION. © ISO 2023

oSIST prEN ISO 22765:2024
ISO/DIS 22765:2023(E)
DRAFT INTERNATIONAL STANDARD
ISO/DIS 22765
ISO/TC 85/SC 5 Secretariat: BSI
Voting begins on: Voting terminates on:

Nuclear fuel technology — Sintered (U,Pu)O2 pellets
— Guidance for ceramographic preparation for
microstructure examination
Technologie du combustible nucléaire — Pastilles (U,Pu)O2 frittées — Préconisations relatives à la
préparation céramographique pour examen de la microstructure
ICS: 27.120.30
This document is circulated as received from the committee secretariat.
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
© ISO 2023
ISO/CEN PARALLEL PROCESSING
THEREFORE SUBJECT TO CHANGE AND MAY
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
NOT BE REFERRED TO AS AN INTERNATIONAL
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NATIONAL REGULATIONS.
Website: www.iso.org ISO/DIS 22765:2023(E)
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NOTIFICATION OF ANY RELEVANT PATENT
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ii
PROVIDE SUPPORTING DOCUMENTATION. © ISO 2023

oSIST prEN ISO 22765:2024
ISO/DIS 22765:2023(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Apparatus . 2
6 Reagents and resin .3
7 Operating procedure . 3
7.1 Specimen cutting . 3
7.2 Resin embedding . 3
7.3 Rough polishing . 3
7.4 Fine polishing . 4
8 Structure development .4
8.1 General . 4
8.2 Development by thermal treatment . 4
8.3 Development by chemical etching . 5
8.4 Development by ion etching . . . 5
Bibliography . 7
iii
oSIST prEN ISO 22765:2024
ISO/DIS 22765:2023(E)
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
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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 documents 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).
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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 installations, processes and technologies
This second edition cancels and replaces the first edition (ISO 22765 :2016), which has been technically
revised.
The main changes are as follows:
— refer to Clause 1, 4, 6, 7 and 8
—
—
A list of all parts in the ISO 22765 series can be found on the ISO website.
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
oSIST prEN ISO 22765:2024
DRAFT INTERNATIONAL STANDARD ISO/DIS 22765:2023(E)
Nuclear fuel technology — Sintered (U,Pu)O2 pellets
— Guidance for ceramographic preparation for
microstructure examination
1 Scope
This document describes the ceramographic procedure used to prepare sintered (U,Pu)O pellets for
qualitative and quantitative examination of the (U,Pu)O pellet microstructure.
The examinations are performed:
— before any treatment or any etching;
— after thermal treatment or after chemical or ion etching.
They allow:
— observation of any cracks, intra- and intergranular pores or inclusions, and
— measurement of the grain size, porosity and plutonium homogeneity distribution.
The mean grain diameter is measured by one of the classic methods: counting (intercept method),
[2].
comparison with standard grids or typical images, etc The measurement of individual grain sizes
requires uniform development of the microstructure over the entire specimen.
The plutonium cluster and pore distribution and localization are generally analysed by automatic
image analysis systems. The plutonium distribution is usually revealed by chemical etching or by alpha
autoradiography. A scanning electron microscope or a microprobe could also be used. In this case an
additional preparation could be needed depending on the equipment. This preparation is not in the
scope of this standard.
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
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 ceramographic preparation of (U,Pu)O pellets involves two steps:
— polishing, after embedding or not the specimen;
oSIST prEN ISO 22765:2024
ISO/DIS 22765:2023(E)
— thermal treatment or chemical etching or ion etching to reveal the specimen microstructure.
The procedure comprises the following operations:
— Step 1 – cutting the specimen;
— Step 2 – resin embedding;
— Step 3 – rough polishing;
— Step 4 – fine polishing;
— Step 5 – a treatment or etching to develop grain boundaries.
The decision to cut the specimen (step 1) mainly depends on the analysis to be perform and on
laboratory products and scrap management. If preferred, cutting the specimen could be replaced by
rough polishing.
The resin embedding operation (step 2) may precede the specimen cutting operation which will be
done in this case with a wire saw. Resin embedding may be skipped when a mechanical device is used
to hold the specimen during polishing.
Rough polishing (step 3) or fine polishing (step 4) could be used for indirect analysis as alpha
autoradiography with film or scintillator.
Mirror finish requires fine polishing (step 4). This surface aspect is required for direct analysis on
the specimen with optical microscopes or scanning electron microscope (grain observation, cracks,
porosities,…).
In case of a treatment or etching has been already done on the specimen, fine polishing (step 4) is
required to obtain a mirror finish.
A treatment or etching (step 5) is required for grain size analysis, after a fine polishing resulting in a
mirror finish.
5 Apparatus
The equipment shall be installed in an environment capable of monitoring specimen containme
...