90 likes | 226 Views
Mid-long term R&D step by step plan in order to implement the recycling at the maximum extension possible. Gunnar Olsson and Lise-Lotte Spontón TW5-TSW-001, D8b Final meeting, TW5-TSW-001 and -002, 23-24 October 2006, UKAEA, Culham, UK. Status of work.
E N D
Mid-long term R&D step by step plan in order to implement the recycling at the maximum extension possible • Gunnar Olsson and Lise-Lotte Spontón • TW5-TSW-001, D8b • Final meeting, TW5-TSW-001 and -002, 23-24 October 2006, UKAEA, Culham, UK
Status of work • A draft report, which is not quite ready for distribution • Report includes chapters about: - recycling classification criteria - the present recycling of radioactive materials - type and quantity of material - R&D areas for fusion waste recycling
R&D areas for fusionwaste recycling General influencing factors when considering recycle and reuse as an option to disposal are technical feasibility, economic constraints, regulatory requirements and public acceptance. For each material a complete recycling scenario should be established and tested step-by-step. Linear decision-tree approach, from IAEA-Tecdoc-1130
1. Common R&D areas for the recycling of fusion material • Further optimization of LAM type materials (e. g. reduction of impurities) • Detritiation methods • - Design improvements to enhance separation/reuse of not damaged parts of in-vessel components
2. Housekeeping-maintenance waste from fusion reactor operation • Study of types and quantities • Tritium contamination • - Decontamination
3. Low level material mainly from decommissioning • Follow-up of clearance regulations (presently IAEA RS-G-1.7) • Separation of materials, accepted/not accepted for clearance • Measuring and averaging methods for authorization of free release • Stainless steel and copper scrap acceptance at commercial smelters? Should all metal first pass a nuclear smelter (good method for measuring)? • Nb-material in superconductive coils, treatment – reuse? • Isolator material (disposal?) • Storage capacity for decay • - Cost comparison with the disposal option (VLLW repository or community land fill)
4. Material within limits for present recycling within the nuclearsector - Define the specific activity and dose rate limits for the use of metal smelters of the present type - Separation of materials (coil mix) - Secondary waste from smelter (slag, filters, furnace linings) quantity, activity, handling (disposal) - Fabrication of stainless steel products in demand within the nuclear sector (steel casks for spent fuel, HLW reprocessing container?) The same for copper. - Nb-superconductor reuse in fusion coils? - Storage capacity for decay before melting/treatment - Cost comparison with disposal options
5. High level materials requiring remote handling (1) • Dismantling and separation of different materials from complex components • Liquid LiPb could be drawn off to a shielded storage tank • Processing for production of radioactive material for reuse (melting to suitable ingots) • - Chemical treatment and Li-refreshment of LiPb • - Tritium and helium control in off-gas • - Fabrication of replacement components from the radioactive ingots (machining and assembling of complicated and heavy components under remote control) • - Possibility to separation of parts of components that could be used without complete reprocessing of the material (e g ITER divertor targets replaced, the cassette reused)
5. High level materials requiring remote handling (2) • Secondary waste • Shielded storage capacity before and after treatment • Other possibilities than melting for recycling of W (or Be in Model B) • Effect from the accumulation of activity by repeated irradiation • Cost comparison with disposal option • Long-lived nuclides do not disappear by recycling • Somewhere the circulation must be interrupted for disposal of some material with accumulated activity contents (e. g. the last installed set of divertor, blanket at final shut-down)