Solid Breeder Blanket R&D and Deliverable

1. Solid Breeder Blanket R&D and Deliverable Presented by Alice Ying TBM Costing Kickoff Meeting INL, August 10-12, 2005

2. Mission statement of HCCB TBM To utilize ITER testing capability to provide critical experimental data to the development of: 1) a breeding technology for producing the tritium necessary for the continued DT fusion research and the extended operation of ITER, and 2) a blanket technology for the extraction of high grade heat and electricity production Mission statement of HCCB R&D Perform “valued research” to gain access to the larger international R&D program (EU and JA) and deliver the 1st test article

3. Key elements of ITER shielding blanket WBS • Detailed design • Development of blanket TSD • Development of FW qualification criteria • Blanket R&D • ITER FW/blanket manufacturing Blanket R&D and Manufacturing Schedule for ITER

4. R&D program on HCCB DEMO & TBM (Typical) • Structural material development and characterization • Fabrication technologies (structural material) • Ceramic breeder and Be multiplier pebbles (or other suitable forms) development and characterization (fabrication and procurement) • Pebble bed characterization • Tritium control and extraction technologies • Tritium cycle modeling • Ancillary systems development (He cooling technology) • Instrumentation development • TBM mockup tests • QA/Qualification Criteria, TSD • TBM fabrication and qualification prior to installation • Current US R&D (except structural material development) is mainly carried out by the graduate students (four at UCLA) • Several R&D projects were initiated, however they were discontinued and/or not pursued in depth because of the continued program changes • The ITER TBM program provides a driving force to bring Fusion Nuclear Technology “R&D” the first step toward reality

5. Indeed, a large R&D program exists in both EU and JA • Can we access it freely? • Is the data available universally? Effective thermal conductivity of Be pebble bed vs. temperature

6. What data needed? What experimental conditions? Recommendations Data Collection Data Assessment ITER TBM MDB Quantification of uncertainty Acceptance of data Unified Procedures (TBD via IEA collaboration?) Processes toward ITER TBM Database Preparation (on breeding elements) As a part of IEA collaboration

7. NT (1st Cut) EM/S

8. Ceramic breeder and Be neutron multiplier:pebble development and characterization • Procurement and quality control of lithium ceramic breeder pebbles (Li4SiO4, Li2TiO3) and Be pebbles • pebble size and shape, low impurity content, mechanical properties, density, microstructure, process reproducibility, production optimization and engineering scaling • Recycling processes for Li, Be • Ceramic breeder and Be pebbles behavior under irradiation (mechanical properties, T release) • Modeling of radiation damage, T kinetics and thermal creep in irradiated Be and of helium and tritium behavior in Be • Improved Be and Be alloys material development (enhanced T release, limited He embrittlement, limited reaction in air)

9. glassy

10. Cost, Risk and Benefit Material Fabrication/Procurement One possible risk: Role of the US on ITER breeding blanket development

11. Three main categories: • Pebble materials • Thermo-physical properties, mechanical properties, tritium release characteristics, irradiation effects, etc. • Pebble bed unit • Effective thermo-physical properties, effective thermo-mechanical properties, irradiation effects, etc. • Breeder unit (with structure) • Stress-strain magnitudes under blanket operating conditions, temperature profiles, deformation profiles, cyclic effects,etc. Scopes of Characterization on Breeding Elements Thermomechanics

12. Uni-axial compression tests have been performed to generate data base of effective modulus and pebble bed creep deformation rate for Li4SiO4 pebble beds Creep strain as a function of creep time

13. CFD analysis and laboratory experiments are needed to verify helium manifold design • Multiple parallel paths per flow distributor • Multiple parallel channels per flow path • The goal is to ensure that helium flow is properly distributed EM/S and NT Unit Cells

15. Tritium permeation: Uncertainties in the database • At higher pressure, the permeation regime appears to be diffusion limited or J~ P0.5, i. e. permeability is governed mainly by hydrogen transport through the bulk. At the lower temperatures and lower pressures (773 K or lower), the pressure dependence of J is somewhat steeper in the low-pressure or J~ P0.63. This can be explained by a more pronounced surface influence on the permeability. • Note that the tritium partial pressure is < 10 Pa in the purge. • Permeability / Solubility data and Pressure effect References: E. Serra, A. Perujo, G. Benamati, “Influence of Traps on the Deuterium Behavior in the Low Activation Martensitic Steels F82H and Batman,” J. Nucl. Mater, 245 (1997) 108-114. A. Pisarev, V. Shestakov, S. Kulsartov, A. Vaitonene, “Surface Effects in Diffusion Measurements: Deuterium Permeation through Martensitic Steel,” Phys. Scr, T94 (2001) 121. D. Levchuk, F. Koch, H. Maier, H. Bolt, “Deuterium Permeation through Eurofer & A-alumina Coated Eurofer,” J. Nucl. Matet, 328 (2004)103-106

16. Summary Table • Calculated permeation rate appears high and unacceptable without taking into account isotope swamping effects or using permeation reduction barriers.

17. Cost Estimates for Unit Cell and Submodule 1. CEA price if purchasing 1 kg. Cost analysis assumes 30% discount if purchase in tenth kg amount, and 50% discount if hundreds of kg. 2. NGK beryllium pebble price. Same discount applied to beryllium cost.

18. Summary • If agreed upon by major responsible parties, the US asa support role can reduce a significant amount of financial burden, yet obtain critical data for breeding blanket and electricity generation technology development • Nevertheless, the US “TBM” should be ready for integration into (e.g. EU) Port Module in 2013 to be inserted into ITER (2014) • Focus on “valued research” (enhanced predictive capability and safety feature) to gain access to a larger data base • Breeder unit thermomechanics • Tritium control and permeation • Additional cost items (US’ contribution: x%) • Port Frame, Port Plug • Helium Loop and associated piping system • Port Cell Coolant Conditioning Components • Tritium Extraction System • Tritium Measurement System • Special Remote Handling Tools • Hot Cell and PIE • Waste disposal