Abstract

This document is applied to fuel fabrication. It describes the ceramographic procedure used to prepare sintered (U,Pu)O2 pellets for qualitative and quantitative examination of the pellet microstructure. The examinations are performed a) before any treatment or any etching, and b) 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), comparison with standard grids or typical images, etc.[2] 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 (SEM) or a microprobe can also be used. In this case an additional preparation can be needed depending on the equipment used. This preparation is not in the scope of this standard.

Begin

2022-11-22

WI

00430107

Planned document number

DIN EN ISO 22765

Project number

06236441

Responsible national committee

NA 062-07 FBR - Board of the Technical Department Nuclear technology and radiation protection  

Responsible european committee

CEN/TC 430 - Nuclear energy, nuclear technologies, and radiological protection  

Responsible international committee

ISO/TC 85/SC 5/WG 1 - Analytical methodology in the nuclear fuel cycle  

draft standard

Nuclear fuel technology - Sintered (U,Pu)O₂ pellets - Guidance for ceramographic preparation for microstructure examination (ISO/DIS 22765:2023); English version prEN ISO 22765:2023
2024-01
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previous edition(s)

Nuclear fuel technology - Sintered (U,Pu)O₂ pellets - Guidance for ceramographic preparation for microstructure examination (ISO 22765:2016); German Version EN ISO 22765:2019
2019-11

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