21 March 1995
Subject: Trip Report - Japan/U.S. Workshop on Fusion Power Reactors
To: J. W. Davis, W. Dove, F. Najmabadi
CC: M. A. Abdou, J. M. Coyle, D. E. Driemeyer, R. J. Krieger, G. D. Morgan, G. W. Wille
From: L. Waganer
Encl: (1) Agenda

1. The 1995 Japan/U.S. Workshop on Fusion Power Reactors was held at Kyoto University, Kyoto, Japan. U.S. participants included F. Najmabadi (UCSD), R. Miller (UCSD), D. Ehst (ANL), D. K. Sze (ANL), C. Wong (GA), and L. Waganer (MDA). Japanese participants were from JAERI, University of Tokyo, and the University of Kyoto. There were also two participants from China (SWIP) and four from EU.

2. Summary - The opening session reviewed the status of the DEMO and power plant studies in the respective country areas. A general consensus is that the U.S. is moving toward a multi-faceted approach stressing advanced materials, low activation materials, and competitive costs. The EU is concentrating on more near-term materials (e.g. Manet) while satisfying safety concerns. The Japanese are also interested in near-term FS materials using either a pulsed tokamak or a helical steady-state reactor. China is very interested in a fusion hybrid reactor to provide adequate fissile fuel for an ambitious energy program.

3. The U.S. representatives outlined the results of the recent U.S. design studies, mainly PULSAR physics (advanced tokamak operating regimes), safety and licensing work, engineering, and systems studies. The physics, engineering, and systems analysis work on the U.S. stellerator design study was also discussed. The work in the advanced materials of vanadium and SiC were described.

4. Japan presented a DEMO concept based upon the present physics and engineering knowledge (i.e., a large inductively-driven tokamak). This machine is pulsed with burn lengths of 5 to 10 hours combined with pumped hydro storage. They are not concerned with BOP cycling, fatigue problems, or costs. A divertor heat load 63 MW/m2 is not viewed as a problem. This machine would use 316SS as the structural material (not a credible approach). As a design exercise, the Japanese are also working on a very large machine called "DREAM" which emphasized easy maintenance with increased cost and machine size. The Japanese also have a large helical experiment, LHD (Large Helical Device), under construction and are exploring DEMO and commercial applications (Force Free Helical Reactor). Japan's power network can accommodate a 3 GW electric power plant as opposed to a 1-1.5 GW plant in the U.S. and EU. They are also developing TiAl as another low activation, advanced structural material.

5. The Europeans emphasized their safety analyses, mainly the Safety and Environmental Assessment of Fusion Power (SEAFP). They have established two models: (a) reduced martensitic steel (LA12TaLC) with LiPb, and (b) vanadium with helium. Both models meet their safety goals. Economics are assumed to be implicit and not stressed as being important. They assumed 18 months to replace the blanket and 12 months for the divertor. Some of the Europeans felt the Demo should be based directly upon the ITER and not be concerned about advanced physics, advanced materials, or suitable economics. The Europeans are also working with the U.S. on low (or tight) aspect ratio devices. They feel this approach has capability for commercial applications.

6. The Chinese feel they have an impending energy crisis. Fossil fuels will pollute China and their neighbors; thus, they will depend on fission. But the supply of Uranium 238 is limited. Therefore, they see a fusion-fission hybrid as breeding adequate fissile fuel while generating power. They presented a design of a breeding blanket. They are also interested in a Volume Neutron Source (VNS).

7. The meeting was viewed as very successful in that many useful ideas and data were exchanged. The common agreement on the promotion of fusion will help advance the common cause. The next workshop is scheduled to be held in San Diego in 18 months.

Lester M. Waganer
McDonnell Douglas Aerospace
Phone: (314)233-8617
Fax: (314)234-4506

Agenda of the Japan-US Workshop on Fusion Power Reactors with Participation of China and EU

(March 13 - 16, 1995 at Kyoto University, Kyoto)

March 13 (Mon) AM: Overview (9:00-12:30)

Welcome Address K. Takahashi
Status of US Power Plant Studies Program F. Najmabadi
Fusion Reactor Studies in China X. Deng
The European SEAFP Project: Overview E. Salpietro
Fusion Reactor Studies in JAERI Y. Seki

March 13 (Mon) PM: Reactor Designs (13:30-17:30)

SEAFP: The Fusion Power Station Models I. Cook
Pulsar System Studies R. Miller
Physics of PULSER and advanced Tokamak regimes D. Ehst
DEMO Reactor based on Presently-established Scientific Knowledge N. Inoue
Physics Design of Inductively-operated Tokamak Fusion Reactor Y. Ogawa
Bootstrap Current Profile Control based on the Density Profile Control
by the Pellet Injection J. Wong
Drastically Easy Maintenance Reactor: DREAM-2 S. Nishio
Divertor Design of DREAM-2 I. Senda

Reception Party (18:00-21:00) at Kyodai Kaikan

March 14 (Tues) AM: Reactor Designs (9:00-12:30)

Tight Aspect Ratio Tokamak Reactor Studies P. J. Knight
The Effect of the H-mode Power Threshold on POPCON
in a Tokamak Reactor O. Mitarai
A Compact Tokamak Reactor Design for VNS's Application L. J. Qiu
Blanket Design (SWIP Version) of a Fusion Engineering Breeder, FEB J. Huang
Engineering Aspects of DREAM-2 T. Kuroda
Pulsar Engineering L. Waganer

March 14 (Tues) PM: Stellarators (13:30-18:00)

Stellarator Power Plant Physics J. Lyon
Stellarator Power Plant Engineering Dai-Kai Sze
Stellarator Power Plants System Studies R. Miller
Design Status of Force-free Helical Reactor (FFHR) O. Motojima
Design Study on Blanket and Coolant in FFHR A. Sagara
Conceptual Design for Divertor of FFHR S. Ohyabu
Structural Design for FFHR S. Imagawa

March 15 (Wed) AM: Environment & Safety (9:00-12:30)

SEAFP: The Safety and Environmental Assessment N. P. Taylor
Safety And Licensing Of Fusion Power Plants C. Wong
Improvement of Tritium Burn-up Rate A. Fukuyama
Fusion Safety Data Base I. Aoki
Fusion Safety Experiments in JAERI T. Kunugi
R&D on Advanced Structural Materials A. Kohyama

March 15 (Wed) PM: Tour of Fusion Facilities/Cultural Sites (13:30-18:00)

Sukiyaki Party (18:30-21:00)

March 16 (Thurs) AM: Materials, Strategy and Future Collaborations (9:00-12:30)

SiC/SiC Material Review S. Ueda
V-alloy Structural Material Dai-Kai Sze
Latest US Information on SiC Composites C. Wong
Comments on Methodology of Comparison between Various Types of Fusion Power Reactors K. Okano
Improvements for DT Tokamak Power Reactor Concept K. Yoshikawa
The Potential of Isotopic Tailoring for Minimizing Radioactivity of
Fusion Structural Materials T. Muroga

Discussions on Future Collaborations