Euradwaste '08 - EU Bookshop - Europa
Euradwaste '08 - EU Bookshop - Europa Euradwaste '08 - EU Bookshop - Europa
agreed for support through an integrated effort at the European level despite the diversity among the Member States in terms of the fuel cycle policy. A key criterion for the selection of projects and activities to be co- funded by the European Union is the “European Added Value”. As shown in Fig.1 the projects are organised coherently to provide all elements necessary for a better understanding and control over the various components required for the deployment of P&T at an industrial scale level in the 2020 to 2040 time scale. Fig. 1 EC co-funded P&T projects 2.1 The Coordinated Action PATEROS This Coordinated Action aims at the establishment of a European vision for the deployment of P&T up to the level of industrial implementation. It should serve as a basis for decisions on advanced fuel cycles leading to a sustainable nuclear energy and thus is intended to provide input for the structuring of the corresponding part of the Sustainable Nuclear Energy Technology Platform (SNE-TP). Performance characteristics of various options for transmutation systems were evaluated e.g. Multi recycling in fast reactors (FR) of TRU unloaded from LWRs and, successively, from FRs. Reduction of TRU inventory in fuels unloaded from LWRs. Reduction of MA inventory. Use of different fuel types and coolants in critical systems as well as the impact of different recycling (e.g. homogeneous and heterogeneous MA recycling) has been studied [1]. Such strategies necessitate fuels with variable amounts of MA incorporated in conventional fuels. The results of the PATEROS programme have been complemented by those obtained in the EISOFAR project for sodium cooled systems and the ELSY project for lead cooled systems. Though dependent on design optimisation, the generic transmutation characteristics for different coolants and homogeneous re- 114
cycling fuels do not vary significantly for critical low conversion ratio systems. In general, the introduction of MA leads to a beneficial effect on the reactivity variation with burn-up but results in slightly worse reactivity feedback effects concerning the Doppler and the void reactivity. For large size sodium cooled reactors (SFR) with about 3000 MWt a maximum MA content of 2.5 to 3.5 % is acceptable from a safety point of view. In the case of a large gas cooled fast reactor (GFR), this upper limit could become higher i.e. up to about 5 to 7 %. A yet higher MA content (e.g. for U-free fuels with a MA content > 40 %) can result in a very significant decrease of the delayed neutron fraction which might result in problems regarding safety. Heterogeneous actinide recycling provides the possibility to circumvent this disadvantage and - more importantly - to disconnect the minor actinide cycle from the conventional fuel cycle. 2.2 Fuels for homogeneous recycling The incorporation of minor actinides into fuels for fast reactors represents an immense challenge. The reprocessing plants must deliver actinide streams suitable for conversion to solid and further processing. Traditionally, mixed oxide fast reactor fuels have been prepared from UO2 and PuO2 powders fed from the separated U and Pu streams in the PUREX process enabling flexibility in preparing fuels with varying Pu enrichment via standard powder metallurgical routes. Introduction of minor actinides (MA) will immediately require full automation of the entire fabrication process, including assembly production, transport and storage. Research on minor actinide bearing fuels is still in its infancy; and major experimental programmes are needed before such fuels can be licensed for industrial application. The SUPERFACT experiment [2, 3] represented the first major milestone in this area. A total of eight fuel pins with pair wise four fuels were manufactured at the JRC-ITU using the sol gel liquid to solid conversion route, as this method has the distinct advantage that it is nearly dust free, and thereby minimises radiation dose risk within the facility. The selected compositions represent both homogeneous and heterogeneous (MA targets) minor actinide recycling in fast reactors (see Table 1). The irradiation was performed during 360 EFPD (equivalent full power days) in a standard Phenix bundle, within which the standard MOX fuel operated at linear powers of 430 and 370 at beginning and end of life (BOL and EOL), respectively. 115
- Page 79 and 80: Cooperation in the development of g
- Page 81 and 82: During the 1980’s it was realized
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- Page 88 and 89: Discussion: The chairman opened the
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- Page 99 and 100: Times & doses in perspective (examp
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- Page 103 and 104: PANEL DISCUSSION Summary of the Pan
- Page 105: 4. The regulators could play a very
- Page 108 and 109: Europe's nuclear industries, theref
- Page 110 and 111: filled - one key example being coll
- Page 112 and 113: Table 2. FP6 Integrated Projects an
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- Page 122 and 123: significantly reduce the quantities
- Page 124 and 125: Pyrochemical processes rely on refi
- Page 126 and 127: Figure 3: Schematic layout of an el
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- Page 136 and 137: Figure 6: Principle design characte
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- Page 142 and 143: After a review of the present statu
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- Page 148 and 149: high level waste at the considered
- Page 150 and 151: Pu or M.A. by the time it is needed
- Page 152 and 153: of U and Pu only. P&T could complem
- Page 154 and 155: suranium elements, the thermal load
- Page 156 and 157: Phase-Out TRU Transmutation Scenari
- Page 158 and 159: 10 nuclear nations (Argentina, Braz
- Page 160 and 161: elease, strong radiation, pressure
- Page 162 and 163: A1 3.79E+08 270 7.12E-07 A2 3.51E+0
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- Page 166 and 167: 5. Conclusions The HLW arising from
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agreed for support through an integrated effort at the European level despite the diversity among the<br />
Member States in terms of the fuel cycle policy. A key criterion for the selection of projects and<br />
activities to be co- funded by the European Union is the “European Added Value”. As shown in<br />
Fig.1 the projects are organised coherently to provide all elements necessary for a better understanding<br />
and control over the various components required for the deployment of P&T at an industrial<br />
scale level in the 2020 to 2040 time scale.<br />
Fig. 1 EC co-funded P&T projects<br />
2.1 The Coordinated Action PATEROS<br />
This Coordinated Action aims at the establishment of a European vision for the deployment of P&T<br />
up to the level of industrial implementation. It should serve as a basis for decisions on advanced<br />
fuel cycles leading to a sustainable nuclear energy and thus is intended to provide input for the<br />
structuring of the corresponding part of the Sustainable Nuclear Energy Technology Platform<br />
(SNE-TP).<br />
Performance characteristics of various options for transmutation systems were evaluated e.g.<br />
Multi recycling in fast reactors (FR) of TRU unloaded from LWRs and, successively, from<br />
FRs.<br />
Reduction of TRU inventory in fuels unloaded from LWRs.<br />
Reduction of MA inventory.<br />
Use of different fuel types and coolants in critical systems as well as the impact of different recycling<br />
(e.g. homogeneous and heterogeneous MA recycling) has been studied [1]. Such strategies<br />
necessitate fuels with variable amounts of MA incorporated in conventional fuels. The results of the<br />
PATEROS programme have been complemented by those obtained in the EISOFAR project for sodium<br />
cooled systems and the ELSY project for lead cooled systems. Though dependent on design<br />
optimisation, the generic transmutation characteristics for different coolants and homogeneous re-<br />
114
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