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ARIES Documents -- Meetings Archive

ARIES Project Meeting, 28-29 January1999

Documented by A. R. Raffray

UC San Diego


List of Attendees

  1. ANL: D. K. Sze
  2. GA: V. Chan, R. Stambaugh, C. Wong
  3. INEL: D. Petti
  4. MIT: L. Bromberg
  5. PPPL: C. Kessel, S. Jardin, W. Reiersen
  6. RPI: D. Steiner
  7. ORNL: M. Peng
  8. TSI: E. Cheng
  9. UCSD: C. Baker, M. Hu, T. K. Mau, R. Miller, F. Najmabadi, R. Raffray, M. Tillack, X.Wang
  10. UW: L. El-Guebaly, I. Sviatoslavsky

Purpose of the Meeting

1. To wrap-up the ARIES-ST study

2. To discuss the advanced physics and technology tasks to be addressed during FY99

3. Briefing on NSTX, FPA meeting, Snowmass meeting and US/Japan workshop in Kyoto.


Farrokh Najmabadi started the meeeting by briefing the team on the latest news on the administrative side. He mentioned the on-going socio-economics studies being carried out at the University of Tennessee, PNL and the University of Wisconsin. Following a suggestion by Don Steiner, Farrokh mentioned that we should plan on inviting investigators from these studies to make presentations at a 'Town Meeting' in concert with the next project meeting.

Special FE&D Issue on ARIES-ST

Farrokh outlined the schedule for FE&D articles to wrap-up the ARIES-ST study:

- papers should be completed and internally reviewed for consistency by end of February.
- papers should then be sent to Farrokh (text in LaTeX form and figures as postscript files)
- papers will be sent to publisher in March/April for publication this summer

Authors should prepare a final presentation in each task area and send to Farrokh or Mark Tillack, together with an html version if possible.


Detailed information from the talks can be obtained from copies of the individual presentations. Here, some major points are summarized:

Assumption on beta and PF coil current:

There is an inconsistency between the assumed PF coil positioning and current and the resulting beta for ARIES-ST. The 60% beta assumption results in very high current in particular in the divertor area coils where space is limited. As an action item, Chuck Kessel will run a few cases to verify whether pulling the other PF coils inside the TF coil might alleviate this problem. Based on his results the logic behind the write-up in this area will be developed.

Advanced Physics Issues for FY99

The tasks in this area have been formulated and presented by Steve Jardin and Chuck Kessel in three general categories:

I. Gain input from the Advanced Tokamak Community regarding ARIES-RS parameters
II. Refine Advanced Tokamak analysis for ARIES-RS
III. Extend the ARIES analysis with new insights

Detailed of the different subtasks presented and adopted for further study can be found in copies of the presentation.

Advanced Engineering Issues to be Considered in FY99

The following possible tasks were discussed:

I. Use of HT SC
Leslie Bromberg presented some new and exciting possibilities in this area, including a specimen of freshly baked HT SC material and will proceed with this activity.

II. Ferromagnetism
Ferritic steels are considered as leading structural material candidates internationally but there is still some discussion regarding their compatibility with tokamak operation. Their effect can be grouped in three general categories: plasma interface; engineering interactions; and diagnostic interactions.

It is proposed to carry out a literature survey and to ascertain whether potential show stopper(s) exist. A strategy and R&D plan could then be evolved to address key issues.

It is proposed to initiate a mini study to evaluate the possibility of a SiC blanket operating at high temperature to maximize the Brayton cycle efficiency. Curently an ~45% efficiency can be obtained from the Brayton cycle as confirmed by D. K. Sze's presentation. The possibility of operating with He at ~900oC would significantly increase the efficiency and correspondingly decrease the COE.

IV. Reliability
The discussion revolved on how to push the field beyond 'weld-counting' and better quantify reliability for fusion reactors. Avenues to explore include looking at the experience in other fields in order to generate reliability curves both for a family of machines and for a single machine. The availability histories of the large Tokamak machines when needed to operate would also help in forging an overall picture.

An effort in this area would help project a more positive view of the potential reliability of fusion reactors. It will also be timely as a Snowmass session on reliability has been planned and will be chaired by Mark. There will be also an IEA meeting on reliability in March.

Other Fusion Applications

Neutron Source Study

Don Steiner presented an initial survey of recent literature in this area. He emphasized the high end side (~1019 n/s) rather than for the low end side (1011-1013 n/s). Competitors include proven technologies: fission reactors and accelerators. Possible advantages are the fusion spectrum and the fact that all fusion neutrons are available whereas only excess neutrons are available from fission. Don will lead an activity in this area, generating a plan of attack to address the two main issues: 1. How much of a market is there for neutrons? and 2. How cheaply can neutrons be produced from fusion a compared to other sources?

Laila El-Guebaly agreed to consider preparing a presentation for the next project meeting on 'low-end' neutron source applications, particularly medical therapy neutron and proton sources.

Actinide Transmutation

Ed Cheng presented the possibility of using fusion neutrons for transmutation of excess weapon-grade plutonium from the RF and the US though a driven device (typical parameters: Q>1, fusion power ~500 MW, wall loading <3 MW/m2 and availability >50%). However, the timing is tight (~10 years) and it is not clear whether such a device could be credibly proposed.

ARIES-RS Ground Rules

The bottom line in guiding the ARIES-RS activities can be summed up as (paraphasing R. Goldston's words at the FPA meeting, as reported by Ron Miller):

Is it cheap? (COE)
Is it clean? (low activation materials, safety)
Is it real? (credible technology and physics basis, reliability)

To help in obtaining consistent numbers, a question for the Snowmass meeting would be: Can the fusion community arrive at a common way of costing different reactors?

Conference Papers

ARIES-ST papers for ISFNT and SOFE:

- In general prior to submission to a conference, authors should send abstracts to Farrokh for coordination.

Future Meetings

E-Meeting: March 16 from 9 am to noon PST

US/Japan workshop: March 24-26, 1999 (list of participants from ARIES to be confirmed)

Project Meeting: May 3-4 in Chicago or Madison

ARIES Project Meeting

January 28-29, 1999

479 EBU-II

Thursday, January 28

8:30 AM
Welcome and agenda reviewTillack
Opening remarksNajmabadi, Dove
8:45 AM - Session 1. ARIES-ST wrap-up
8:45 Boundary shape studies Kessel
9:00 Materials issues Billone
9:20 Power conversion issues Sze
9:40 Final strawman and economic modeling Miller
10:00 AM -- coffee break
10:30 AM -- Session 2. Community Interactions
10:30 Latest progress in the construction of NSTXPeng
10:50 FPA meeting summary Miller
11:10 Snowmass plansNajmabadi
11:40 US/Japan Workshop in Kyoto Najmabadi
12:00 Noon -- Lunch
1:30 -- Session 3. Discussions on Planning for FY99
1:30 Advanced tokamak physics issues Jardin
2:15 Advanced power plant engineering issues Raffray
3:00 Use of HT SC in fusion Bromberg
3:20 IEA reliability activitiesPetti
3:40 Plans for ARIES neutron source studiesNajmabadi
4:00 Actinide transmutation using fusion neutronsCheng
4:20 Open discussion

Friday, January 29

8:30 -- Closing Session
Discussions on Planning for FY99, continued (if needed)
Administrative items
Meeting, conference call and e-meeting schedule
Town meetings
ARIES-ST Final Report, review session
1. Status Najmabadi
2. Break-out sessions for review
Adjourn at Noon

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