ITER test plan for the solid breeder TBM

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

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 design development will 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

Testing strategy calls for different issues to be addressed aligned with ITER operational plan 7 8 9 Neutronic test unit cell 6 First wall structural response and transient EM/ disruption tests 0. 006 0. 008 0. 012 0. 020 0. 024 Breeder in 300 C Coolant plates Unit cell wall out 300 C 0. 024 Neutronics and tritium production rate prediction tests Beryllium in 100 C High Duty D-T 5 0. 0 4 0. 0 3 2 1 0. 0 Low Duty D-T D-plasma 10 H-plasma out 500 C Thermo-mechanics test unit cell Tritium release, thermomechanical interaction and design evaluation tests • Main difference is breeder layer toroidal dimension, which determines T gradient Initial study of irradiation effects on performance • Coolant flow conditions (unit cell operational T) are varied to address different issues

Unit cell strategy EM-TBM NT-TBM TM-TBM PI-TBM ITER Master Schedule HH and DD Earlier DT DT DT ITER Operational Year 1 -4 5 6 -8 9 -10 Delivery Year -2 2 5 8 Ancillary Equipments Helium Loop To Share Ancillary Equipment Tritium Processing To Share Instrumentation in Port Area ICC, OCM, DAS TMS, ICC, OCM, DAS Number of units in EU HCPB TBM 3 3 3 3 Total Helium Mass Flow Rate [kg/s] 0. 1 Helium Pressure [MPa] 8 8 Helium Pressure Drop [MPa] < 0. 02 < 0. 01 – 0. 05 Helium inlet/outlet temperature [ o. C] 300/500 or 100/300 300/500 FW Beryllium (2 mm) < 346 545 FW Structure < 340 539 Coolant Plate Structure < 200 550 Beryllium Pebble Bed 300 (DD) 300 600 -650 Ceramic Breeder Pebble Bed 350 (DD) 350 900 Helium Purge Gas Pressure [MPa] NA NA 0. 1 Total Helium Purge Gas Flow Rate [g/s] NA NA 0. 3 g/s [6 Nm 3/s] Purge inlet/outlet temperature [ o. C] NA NA TBD/450 Special feature Instrumented activation foil capsules Design Maximum temperature [o. C] ¼ port submodule could be implemented instead or along with unit cells ICC: Inlet coolant conditionner; OCM: Outlet coolant mixer; DAS: Data acquisition system; TMS : Tritium measurement system

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

Piping arrangements in the port area pipes 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

High and low cost options share most R&D issues: Tritium Measurement System optional Located at PIC at Port Cell Space: 1 x 1 m 3 for 2 systems

Continued design effort for TM ¼ sub-module: Helium thermal-hydraulic design and parameters First wall outlet manifold (also layer breeding units inlet manifold) (T= 353 o. C) First wall inlet manifold (Tin= 300 o. C) Layer breeding units outlet manifold (T=500 o. C) 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=353 o. C Edge-on breeding units outlet manifold (1/2) T=500 o. C 1 of 10 alternative cooling flow paths

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

First wall thermo-mechanical analysis (FEM of 5 Channel TBM Section) mm 600 5 -Channels 940 mm } 5 -mm thick FW 44. 5 mm 73 0 m m He Tin = 300 o. C/Tout= 353 o. C 5 -Channel Pass Detail of the FW

Thermal Analysis Results • Temperatures distributions are not symmetric because of 5 passes and a non-uniform heating q’’=0. 25 MW/m 2 profile q’’=0. 5 MW/m 2 Max Temp: 523 o. C h=5890 W/m 2 -K

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) • 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 Independent cooling and variable manifold design allows for flexible temperature distribution in the different sections of NT and TM unit cells (see hydraulic analysis)

Pebble beds thermo-mechanic behavior and tritium release properties after long-term exposure to fusion pulsed loads will be investigated by TM unit cells Prototype model (EU design) smax= 1. 75 MPa dmax = 0. 41 mm at 21 cm smax= 2. 35 MPa dmax = 0. 18 mm at 15. 2 cm Fixed Y BC X Y Modified ITER Scale model Fixed x BC 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 Stress evolution at mid-plane of ITER scale model

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.