Satoshi Konishi Institute of Advanced Energy, Kyoto University

1. Institute of Advanced Energy, Kyoto University FUTURE BLANKET AND REACTOR STUDIES (ITER TBWG/WSG2 and possible JA involvement) Satoshi Konishi Institute of Advanced Energy, Kyoto University Contents - Current status of Japanese tokamak reactor design studies - Reactor design studies and ITER TBWG programs - Future advanced reactor concepts and development strategy - Technical issues

2. Institute of Advanced Energy, Kyoto University Energy Demonstration in 2030? Technical feasibility Combined Demo-Proto steps Social feasibility Fast Track : the next step Fusion study is in the phase to show a concrete plan for Energy. -Power plant design and strategy following ITER are required. Common understanding ・Resource constraint (Energy) ・Global warming problem (Environment) ・Growth in developing countries (Economy) Strategy varies in each Parties due to different social requirements.

3. Japanese reactor studies Institute of Advanced Energy, Kyoto University Power plant designs - SSTR(1990s) : 300C water cooled, pebble beds - A-SSTR2 : 900C He cooled pebble beds - DEMO(2000) : 500C supercritical water, pebble beds - VECTOR : ? He cooled LiPb - FFHR : FLiBe - Laser (FIREX) : Pb, LiPb

4. Current blanket concepts Institute of Advanced Energy, Kyoto University ○Almost all types of blankets are considered for TBM ○SiC-Heconcepts not planned by TBWG ○LiPb-Hecool – SiCconcepts attracts interests of reactor design 　－EU：Tauro,PPCD-c,d 　－US:ARIES-AT,ST 　－JA:Vector Possible high temperature, high burnup, low waste ○Japan does not have LiPb program ●Laser fusion (fast ignition) reactor application

5. Institute of Advanced Energy, Kyoto University Design in US Aries-AT（self cooled – He turbine）

6. Institute of Advanced Energy, Kyoto University European program

7. Institute of Advanced Energy, Kyoto University Tokamak designs Higher temperature and less solid waste ~5 MW/m2 ~10 MW/m2 ~1 MW/m2

8. Institute of Advanced Energy, Kyoto University 1 6 m R = 2 . 8 m p A = 2 V E C T O R ( ~ 9 0 0 0 t o n ) P = 3 . 7 G W F JA advanced reactor concept Shield：MH Blankets：SiC、LiPb Divertor：W Shield：W、Pb

9. Power Plant Design Institute of Advanced Energy, Kyoto University • -From the aspect of thermal plant design, • ONLY supercritical water turbine is the available option • From fire-powered plant technology. • -No steam plants available above 650 degree C. • Near Future Plants • -Reduced Activation Ferritic steels (RAFs) are expected as • blanket material candidates. • -Considering temperature range for RAFs, 500 C range • is maximum, and desirable for efficiency.

10. Institute of Advanced Energy, Kyoto University directindirect He gas Main steam pressure25MPa 16.3MPa 10MPa Turbine temp. 500℃ 480℃ 500 ℃ Coolant flow rate1250kg/s 1260kg/s 1865kg/s Vapor flow rate 1250kg/s 1037kg/s 908kg/s Total generation 1200MW 1090MW 1028MW Thermal efficiency 41.4% 38.5% 35.3% Technical issuestritium insteam expansion coolant generator volume Comparison of Generation Cycles Other thermal Plants: BWRs – 33% PWRs – 34% Supercritical Fire – 47% Combined gas turbine - >60%

11. Reduction of rad-waste Institute of Advanced Energy, Kyoto University Complex remote Simple remote Possible Hands on Clearance and recycling are considered for waste reduction. LiPb offers easier recycling SiC/SiC offers a recycling advantage over other materials. After 30 y cooling, SiC/SiC is recyclable by simple remote handling.

12. Institute of Advanced Energy, Kyoto University Current status ○Japan has little experience with LiPb. ○LiPb-SiC concept itself could be tested earier 　・broad temperature window（２４０℃～>１０００℃？） 　・high coverage（TBR？） 　・easy production of breeder 　・easier constraint against tokamak disruption ○staged apploication into other gas cooled concepts as an alternative ○common technical issues with GIF.

13. Institute of Advanced Energy, Kyoto University Development strategy （main program） （high temperature） （Disruption） RAF （integrity、TBR） （economy） PB （safety, compatibility） （safety） Water cool He cooled Thermal design compatibility LiPb Irradiation, production SiC （alternative） “Alternate” in case of difficulty in main program

14. Institute of Advanced Energy, Kyoto University Fast track strategy 2000 2010 2020 2030 Power Demo Design Concept Const. Test Generation ITER BPP Const. EPP TBM module1 module2 Tokamak High beta, long pulse Test IFMIF KEP Const. EVEDA New line 10dpa/y 20dpa/y RAF In pile irradiation 1/2 irrad. Full irrad. SIC Feasibility issues irradiation Blanket R&D Drawn from Fast track working group, 2002,Dec.

15. Conclusion Institute of Advanced Energy, Kyoto University Japanese university activity will include LiPb as an alternative 　・possible involvement in ITER/TBWG-SWG2 　・Staged application to SWG1 He cooled concepts 　・early deployment with some advantages will be considered Japanese “Fast track” requires 　・improvement of fusion energy during DEMO phase 　・economy: higher temperature, availability, hydrogen 　・reduced waste: improved design, recycling Technical issues 　・compatibility 　・heat transfer 　・neutronics and system design 　・container/coolant channel fabrication 　・TBM design and R&D