ISO 15646:2014 PDF
Re-sintering test for UO2, (U,Gd)O2 and (U,Pu)O2 pellets
Re-sintering test for UO2, (U,Gd)O2 and (U,Pu)O2 pellets
- Статус документа:
- Действующий
- Формат:
- Электронный (PDF)
- Количество страниц:
- 6
- Дата публикации:
- 13 июня 2014 г.
- Издание:
- ISO IS 15646 edition 1 version 1
- ICS:
- 27.120.30
ISO 15646:2014 describes a procedure for measuring the densification of UO2, (U,Gd)O2, and (U,Pu)O2 pellets, achieved by heat treatment under defined conditions. The densification of fuel in power operation is an important design feature. Essentially, it is dependent on structural parameters such as pore size, spatial pore distribution, grain size, and in the case of (U,Gd)O2 and (U,Pu)O2, oxide phase structure. A thermal re-sintering test can be used to characterize the dimensional behaviour of the pellets under high temperature. The results of this test are used by the fuel designer to predict dimensional behaviour in the reactor, because thermal densification in the reactor is also dependent on these structural parameters, albeit in a differing manner in terms of quantity.
Abstract
Overview
ISO 15646:2014 specifies a standardized re‑sintering test for UO2, (U,Gd)O2 and (U,Pu)O2 fuel pellets to measure thermal densification after controlled heat treatment. The standard defines how to measure pellet density before and after a high‑temperature hold under a specified atmosphere so that fuel designers and manufacturers can assess dimensional stability and predict in‑reactor behaviour linked to microstructural parameters (pore size/distribution, grain size, oxide phase).
Key topics and technical requirements
- Purpose: determine densification (density change) produced by thermal re‑sintering and evaluate thermal stability of pellet lots.
- Density measurement: perform the same method before and after re‑sintering. Typical methods:
- Geometric method (diameter/height with 1 µm precision micrometer; balance 1 mg precision) - preferred when open porosity is significant.
- Buoyancy/immersion method (suitable for chipped or cracked pellets) - follow referenced ISO procedures.
- Heat treatment parameters:
- Programmable furnace capable of ~1 800 °C with gas scavenging and dual thermocouples for control/monitoring.
- Heating/cooling rate:
Технические детали
- Технический комитет
- ISO/TC 85/SC 5 - Nuclear installations, processes and technologies
- SKU
- ISO 15646:2014
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