Characterisation and fabrication of zirconia and thoria based ceramics for nuclear applications [Elektronische Ressource] / vorgelegt von Diane Catherine Barrier

Diane Barrier

Informations

• Publié par: rheinisch-westfalischen_technischen_hochschule_-rwth-_aachen
• Publié le: 01 janvier 2005
• Nombre de lectures: 21
• Langue: Deutsch
• Poids de l'ouvrage: 8 Mo

Extrait

Characterisation and fabrication of
zirconia and thoria based ceramics
for nuclear applications

Von der Fakultät für Georessourcen und Materialtechnik der
Rheinisch -Westfälischen Technischen Hochschule Aachen

zur Erlangung des akademischen Grades eines
Doktors der Ingenieurwissenschaften

genehmigte Dissertation

vorgelegt von Master of science and chemical engineering
(Ingénieur E.N.S.C.P.)
Diane, Catherine BARRIER

aus Poissy, Frankreich
Berichter: Univ.-Prof. Dr. rer. nat. R. Odoj
Univ.-Prof. Dr. rer. nat. R. Telle

Tag der mündlichen Prüfung: 11. November 2005

Diese Dissertation ist auf den Internetseiten der Hochschulbibliothek online verfügbar
Berichte des Forschungszentrums Jülich – Jül-4188 – ISSN 0944-2952 Characterisation and fabrication of zirconia and
thoria based ceramics for nuclear applications
Diane Catherine BarrierBerichte des Forschungszentrums Jülich ; 4188
ISSN 0944-2952
Institut für Sicherheitsforschung und Reaktortechnik Jül-4188
D 82 (Diss., RWTH, Aachen, 2005)
Zu beziehen durch: Forschungszentrum Jülich GmbH · Zentralbibliothek
D-52425 Jülich · Bundesrepublik Deutschland
02461 61-5220 · Telefax: 02461 61-6103 · e-mail: [e-mail]
1. Abstract ................................................................................................. 15
2. General introduction............................................................................ 19
3. The nuclear fuel cycle........................................................................... 21
3.1. The nuclear energy production.............................................................................. 21
3.1.1. The nuclear energy of uranium ................................................................................. 22
3.1.2. The different types of reactor .................................................................................... 23
3.2. The nuclear fuel cycle ............................................................................................. 24
3.2.1. The “front end”..........................................................................................................24
3.2.2. The spent fuel ............................................................................................................ 25
3.2.3. The “back end” 27
3.3. The management of plutonium and HLW............................................................ 29
3.3.1. The radiotoxicity balance .......................................................................................... 29
3.3.2. The management of long-lived elements .................................................................. 30
3.3.3. The partitioning strategies......................................................................................... 31
3.3.4. The transmutation strategies...................................................................................... 32
3.3.5. The conditioning strategies ....................................................................................... 37
3.4. Advanced ceramics for the immobilisation of Pu and MA.................................. 38
3.4.1. Required properties for the ceramics ........................................................................ 38
3.4.2. The different type of advanced fuel .......................................................................... 39
3.4.3. The inert matrices...................................................................................................... 39
3.4.3.1. The characteristics of the matrices (ZrO and ThO )2 2
3.4.3.2. The fabrication routes
3.4.3.3. Summary
3.4.4. The composite material ............................................................................................. 44
3.4.5. ADS fuel - a preselection during the FUTURE project ............................................ 45
3.4.6. Advanced ceramics for the conditioning of Pu and MA........................................... 46
4. Scope of the work ................................................................................. 49
5. Experimental procedures..................................................................... 51
5.1. Materials and Apparatus........................................................................................ 51
5.1.1. Applied materials......................................................................................................51
5.1.2. Apparatus-facilities...................................................................................................51
5.2. Fabrication of powders and pellets........................................................................ 52
5.2.1. Synthesis of the powders........................................................................................... 53
35.2.2. Washing of the powders............................................................................................ 53
5.2.3. Drying and calcination of the powders ..................................................................... 54
5.2.4. Grinding of the powders 54
5.2.5. Fractionation of the powders..................................................................................... 54
5.2.6. Powders compaction.................................................................................................55
5.2.7. Sintering of the pellets............................................................................................... 55
5.3. Characterisation methods for the powders and pellets ....................................... 56
5.3.1. Thermal behaviour of the powders............................................................................ 56
5.3.2. Crystal properties of the materials 56
5.3.3. Morphological structure of the powders ................................................................... 57
5.3.4. Green, sintered and theoretical densities 57
5.3.5. Densification behaviour of the pellets....................................................................... 58
5.3.6. Pellets microstructure and Ce distribution ................................................................ 58
5.3.7. Mechanical properties of the pellets.......................................................................... 59
5.3.8. Oxidation degree of Ce in the pellets........................................................................ 59
6. Kinetics of the precipitation of Ce-YSZ and ThO -CeO ................. 61 2 2
6.1. Hydrolysis of Zr, Y and Ce..................................................................................... 61
6.2. Co-precipitation of Ce-YSZ.................................................................................... 63
6.3. Co-precipitation of ThO - CeO ............................................................................ 65 2 2
7. Yttria fully stabilised zirconia: inert matrix for the immobilisation
of actinides............................................................................................. 67
7.1. Introduction ............................................................................................................. 67
7.2. Physical properties of Ce-YSZ powders................................................................ 67
7.2.1. The thermal behaviour of Ce-YSZ powders ............................................................. 67
7.2.2. The crystallisation of Ce-YSZ powders .................................................................... 71
7.2.3. The crystallisation behaviour of powders with 0 < [CeO ] < 20 wt.% ..................... 74 2
7.2.4. The crystallisation behaviour of powders with 40 < [CeO ] < 100 wt.% ................. 80 2
7.2.5. The effect of ceria concentration on the crystallinity of Ce-YSZ powders after
calcination at low temperatures................................................................................. 81
7.3. Fabrication of 10-Ce-YSZ ceramics ...................................................................... 83
7.3.1. Powders morphology.................................................................................................83
7.3.2. Compressibility of the powder .................................................................................. 84
7.3.3. Sinterability of the material....................................................................................... 87
7.3.4. Densification behaviour of the pellets....................................................................... 89
7.3.5. Microstructure of the pellets ..................................................................................... 92
7.3.6. Comparison with literature........................................................................................ 93
47.4. Fractionation of powders: influence on the powders and pellets properties ..... 96
7.4.1. Characterisation of the powders................................................................................ 96
7.4.2. Compressibility of the powders................................................................................. 97
7.4.3. Sinterability of the pellets ........................................................................................ 99
7.4.4. Densification behaviour and microstructure of the pellets...................................... 101