Presented at the ITER TBM Meeting, February 23-25, 2004, at UCLA Introductory Remarks on ITER TBM Activities and Proposed US Plans Mohamed Abdou Presented at the ITER TBM Meeting, February 23-25, 2004, at UCLA

Background Information With the US joining ITER, the US has decided to redirect most of the resources of the blanket/chamber area toward participation in the ITER Test Blanket (TBM) Program. Extensive deliberations have occurred in the US since July 2003 among the community, DOE, and VLT. A community meeting was held at UCLA November 3–5, 2003, to discuss strategy and approach to the ITER TBM. A strategy has been agreed to. But it is still EVOLVING! Some important work has been carried out to implement the strategy: Special Issues Groups were formed. Some R&D was initiated. The US participated in TBWG-11 and is now active in TBWG and its subgroups. The US interacted with the EU and Japan to identify areas of collaboration.

Highlights of US Strategy for ITER TBM (Evolved over the past several months by the community, DOE and VLT) The US will seek to maximize international collaboration. There is a need for all parties to collaborate, and to possibly consider a more integrated plan among the ITER parties for carrying out the R&D and construction of the test modules. The US must reconsider its previously preferred two blanket concepts in view of new technical results obtained over the past few years. ITER TBM should be viewed as a collaborative activity among the VLT program elements. While the Blanket/Chamber Program provides the lead role for ITER TBM, major contributions from other programs, e.g., Materials, Safety, PFC, are essential. The US will not insist on a “lead role” for any particular blanket concepts. Rather, the US will seek a lead role in particular technical areas where the US has great interest and expertise.

What Should the TWO US Blanket Options be for ITER TBM What Should the TWO US Blanket Options be for ITER TBM? And How to make the Decision? (This has been a central question for the US community, discussed in the November meeting, and it is the focus of this meeting.) Agreed: He-cooled Solid Breeder (pebble bed) Blanket with FS Selected by all parties (EU, J, RF) and has the largest world R&D US has highly focused R&D in niche areas and rich expertise in underlying technical disciplines. US Strategy: Select He/SB/FS as an option but do not have an independent TBM. Rather, plan on unit cell and submodule test articles that focus on particular technical issues of interest to all parties. Liquid Breeder Option Yet to be resolved: Which liquid breeder option? All liquid breeder options have serious feasibility (“Go/No-Go”) issues. The US has initiated a technical study to evaluate these issues. This meeting reports on initial results of that evaluation.

Liquid Breeder Blanket Options and Key Feasibility Issues 1. Self-Cooled Li / V 1. Self-Cooled Li / V 1.A. Li / V was the US choice for a long time. But negative results and lack of progress on serious feasibility issues are ALARMING 1.A. Li / V was the US choice for a long time. But negative results and lack of progress on serious feasibility issues are ALARMING. MHD Effects MHD Effects Coating Development, Crack Tolerance Coating Development, Crack Tolerance Engineering Design Solutions (that may not require coating) Engineering Design Solutions (that may not require coating) Corrosion at High Temperature (coupled to coating development) Corrosion at High Temperature (coupled to coating development) Tritium Recovery and Control Tritium Recovery and Control V Development V Development 2. Lead-Lithium 2. Lead-Lithium 2.A. He-Cooled Pb-Li with FS 2.A. He-Cooled Pb-Li with FS Tritium Permeation (Barrier Development), and Control Tritium Permeation (Barrier Development), and Control Corrosion Corrosion 2.B. Dual Coolant with He-Cooled First Wall and Self-Cooled –Pb-Li breeding zone with SiC INSERT for electrical/thermal insulation (all structure FS) 2.B. Dual Coolant with He-Cooled First Wall and Self-Cooled –Pb-Li breeding zone with SiC INSERT for electrical/thermal insulation (all structure FS) SiC insert compatibility with Pb-Li (Corrosion temperature limit) SiC insert performance integrity (cracks in coating of the insert, etc.) SiC insert performance integrity (cracks in coating of the insert, etc.) Tritium Permeation and Control Tritium Permeation and Control

Liquid Breeder Blanket Options (cont’d) 3. Molten Salt (Flibe/Flinabe) 3.A. Self-Cooled FLiBe with advanced FS structure 3.B.* Self-Cooled FLiNaBe with FS structure 3.C.* Dual Coolant: He-cooled FS structure and self-cooled FLiBe (with no need for insulation) Enhancing heat transfer and MHD effects on heat transfer Redox, tritium recovery and control *Note: 3.B. and 3.C. are innovative ideas that were proposed over the past several months. They are being evaluated. Progress will be reported in this meeting.

Special Issues Groups In order to develop the US strategy for liquid breeder TBM, the US community believes strongly that the key feasibility, “Go/No-Go” issues must first be evaluated in light of recent R&D results. Special Issues Groups were formed to collect and evaluate R&D results as the Key Input to community deliberations: Tritium Permeation (Leader: D. Sze) Corrosion (Leaders: S. Zinkle et al.) MHD Effects (Leader: N. Morley) Molten Salt Design* (Leader: C. Wong) *Note: Designs exist for Li/V and LiPb/He. But no good design is available yet for molten salts. Also, the US has developed creative ideas for novel molten salt designs over the past few months (some were inspired by APEX results). Therefore, an effort to develop a contemporary molten salt design was deemed necessary in order to properly evaluate MS issues.

ITER TBM Highlights TBWG (test blanket working group) was reconstituted in July 2003. The newly reconstituted TBWG met in Garching (TBWG-11) October 22-24, 2003. Chair: Luciano Giancarli (EU, CEA) Co-Chair: Valeriy Chuyanov (ITER Garching, RF) The US members of TBWG are M. Abdou, D. Sze, and M.Ulrickson. The US major contributions to the ITER Test Program since early CDA (and, even earlier, INTOR) were clearly recognized. The US is widely acknowledged as a primary “intellectual power” in fusion testing (many US studies in the 80’s and 90’s: FINESSE, VNS, etc.) The number of ports in ITER have been reduced to three, but the number of parties has increased to six. The US made many suggestions on strategy for the meaningful testing on ITER, stronger collaboration among the Parties on R&D and construction of TBM’s, etc.. These suggestions were well received. TBWG Plans, Port Allocation to Concepts, and Formation of Working Groups for various blanket concepts were accomplished. The next meeting (TBWG-12) will take place March 9 – 13, 2004 in Japan.

Port Allocations for ITER TBM (TBWG: October 2003) Port B Port C He-Cer (1) H2O-Cer Li/V He-Cer (2) He-LiPb Molten Salt Port Master A: Boccaccini Port Master B: Enoeda Port Master C: Shatalov Working Group* Cer/He 2 Working Groups* H2O-Cer He-LiPb Li/V Molten Salt *Members nominated by each interested party (not necessarily members of TBWG).

FIVE TBWG WORKING GROUPS Broad US representation in Working Groups Cer / He All parties - Boccaccini (Leader), Ying EU, US, China, Korea, RF - Poitevin (Leader), Wong He / LiPb H20 / Cer Japan, China - Enoeda (Leader) Li / V RF, US, Japan, China, Korea - Kirillov (Leader), Sze Molten Salt US, Japan, RF, China? - Sze (Leader), Petti

Purposes of This Meeting Review early progress from the Special Issues Groups for ITER TBM. Get briefings on ongoing efforts in the US relevant to ITER TBM from the Blanket, Materials, Safety and PFC programs. Get briefings from EU and Japan about Their efforts on ITER TBM, and Results of R&D on special issues. We thank our colleagues from Europe and Japan for their strong participation in this meeting and for their efforts in preparing presentations on very important topics. Provide a forum for community discussions of Key technical issues relevant to ITER TBM, and US approach and strategy for where to focus most of the US effort on ITER TBM.

Other Meetings and Social Agenda There is a US–Japanese Universities meeting on ITER TBM on Wednesday after the end of this meeting (in this room) There is a JUPITER-II Steering Committee Meeting on Thursday and Friday (this room) Lunches/Dinners and Working Meetings Monday and Tuesday—lunches at the Faculty Center. Lunch on Wednesday will be brought in to the meeting (at the usual time). Monday evening: Free (except for the EU participants). Tuesday evening: Group dinner at Yamashiro, hosted by UCLA. Thursday evening (for JUPITER-II): Group Dinner Need Time for One More Meeting? We need the senior US people to get together for a two-hour meeting on Tuesday, Wednesday or Thursday. When? (Agenda is full)