ITER test plan for the solid breeder TBM

1. ITER test plan for the solid breeder TBM Presented by P. Calderoni March 3, 2004 UCLA

2. The unit cell strategy as a time staged, low cost option for the US solid breeder test plan 3 unit cells in EU HCPB TBM 192.5 mm x 211 mm x 650 mm ¼ port sub-module designdevelopmentwill continue for possible integrated “act-alike” testing in high duty D-T phase • No need for independent structural design / verification • Simplified interface requirements (He in / out, T analysis) • Focusing on relevant technical issues

3. H-plasma D-plasma Low Duty D-T High Duty D-T 10 8 9 1 3 4 5 6 2 7 0.0 0.0 0.0 0.006 0.008 0.012 0.020 0.024 0.024 0.0 Thermo-mechanics test unit cell Initial study of irradiation effects on performance Testing strategy calls for different issues to be addressed aligned with ITER operational plan First wall structural response and transient EM/ disruption tests Neutronics and tritium production rate prediction tests Neutronic test unit cell Breeder Beryllium Coolant plates Unit cell wall in 300 C out 500 C Tritium release, thermomechanical interaction and design evaluation tests in 100 C out 300 C • Main difference is breeder layer toroidal dimension, which determines T gradient • Coolant flow conditions (unit cell operational T) are varied to address different issues

4. ¼ port submodule could be implemented instead or along with unit cells

5. Simplified interfaces at port plug within EU TBM module EU design already accommodated independent coolant line to control unit cell temperature after coolant conditioner – only interface required for NT unit cells Flow control within the 3 unit cells and independent heater can be installed in the PIC (piping integration cask) along with the separate purge He outlet for independent T concentration measurement for TM unit cells

6. Piping arrangements in the port areapipes are bent within the available space to accommodate thermal expansion while reducing neutron streaming PIC (piping integration cask) to house measurement and flow control systems One Integrated PIC located in Port Cell

7. High and low cost options share most R&D issues: Tritium Measurement System optional Located at PIC at Port Cell Space: 1x 1 x 1 m3 for 2 systems

8. First wall outlet manifold (also layer breeding units inlet manifold) (T= 353oC) Layer breeding units outlet manifold (T=500oC) First wall inlet manifold (Tin= 300oC) Mass flow rate In: 0.9 kg/s Out: 0.82 kg/s By-pass: 0.08 kg/s Edge-on breeding units inlet manifold (1 of 2 alternative paths) T=353oC 1 of 10 alternative cooling flow paths Edge-on breeding units outlet manifold (1/2) T=500oC Continued design effort for TM ¼ sub-module: Helium thermal-hydraulic design and parameters

9. Be purge outlet TC instrumentations Flexible support (1/4) Helium outlet By-pass line common back plate Breeder purge outlet Key (1/3) Instrumentation Breeder purge inlet Helium inlet Be purge inlet Electric connection Shared interfaces (with J HCPB TBM module) at port plug

10. First wall thermo-mechanical analysis(FEM of 5 Channel TBM Section) 600 mm 5-Channels } 940 mm 5-mm thick FW 44.5 mm 730 mm 5-Channel Pass Detail of the FW He Tin = 300oC/Tout= 353oC

11. Temperatures distributions are not symmetric because of 5 passes and a non-uniform heating profile q’’=0.25 MW/m2 q’’=0.5 MW/m2 Max Temp: 523 oC h=5890 W/m2-K h=5890 W/m2-K Thermal Analysis Results

12. Technical issues addressed by unit cells are the same as the planned sub-module:neutronic tests are designed to perform initial check of neutronic code and data (neutron flux spectrum, tritium production and heating generation rates) Independent cooling and variable manifold design allows for flexible temperature distribution in the different sections of NT and TM unit cells (see hydraulic analysis) • Instrumented with activation foil and breeder capsules for spectrum and tritium production measurements • Operated at low temperatures in order to freeze tritium • Complex one- and two-D performance features for code evaluations

13. X Y Pebble beds thermo-mechanic behavior and tritium release properties after long-term exposure to fusion pulsed loads will be investigated by TM unit cells Near term research work focuses on pebble bed thermo-mechanical integrity and performance under thermal heat cycles and the development of predictive capabilities to be included in FEM codes for blanket integrated analysis Prototype model (EU design) Modified ITER Scale model smax= 1.75 MPa dmax = 0.41 mm at 21 cm smax= 2.35 MPa dmax = 0.18 mm at 15.2 cm Stress evolution at mid-plane of ITER scale model Fixed Y BC Fixed x BC

14. Summary Concepts and framework required for ITER interface integration have been defined for the US solid breeder TBM program. The DDD report will be delivered. The US goal is to emphasize international collaboration among the interested parties. The design of a ¼ port integrated sub-module has already been presented and R&D continues on key issues, such as 3-D structural analysis. The unit cell approach has been developed as a time staged, lower cost option. Variable temperature distributions by means of flow control and independent T monitoring in the unit cells will allow effectively addressing scientific and technical issues for which the US community has extensive accumulated expertise.The ¼ port sub-module could be implemented in the high-duty DT phase for integrated thermo-mechanical testing. R&D on pebble bed thermo-mechanics and first wall helium flow hydraulics will continue as the near term focus along with ITER TBM engineering design, while ITER siting and collaborative agreements are being established.