ARIES Documents -- Meetings ArchiveARIES Conference Call, 16 December 2008
Documented by L. Waganer
Les Waganer affirmed the dates for the next project meeting that will be held in San Diego on January 21-22, 2009, with January 21 (Wednesday) being a full day and January 22 (Thursday) only a morning session.
The FESAC meeting is still planned to be held in Washington, DC, on January 13-14, 2009 and may cover the TRL presentations. This is still tentative as the agenda has not been finalized or issued, but the TRL discussions are still planned for the meeting. Tom Weaver has been working with Dr. Whelan, Boeing, on his presentation. Mark Tillack will also be presenting TRL information. A conference call will be held as planned on January 6, Tuesday, (primarily to preview the FESAC TRL presentations being prepared by Tillack and Weaver).
Report of High Heat Flux Divertor Workshop
Rene Raffray reported that the High Heat Flux Components Workshop, December 10-12, 2008, was very successful with a large group of participants attending. The technical exchange was excellent and many points of view were presented. There were 33 attendees from the US, EU, and Japan. The agenda is available on the ARIES web page for the IHHFC workshop with links to the presentations.
Mark Tillack opened the workshop with a welcome from the UCSD Center of Energy Research. Rene Raffray outlined the background and goals established for this workshop. Session 1 addressed the Near Term HHFC Design and R&D. The near term divertor work dealt mostly with ITER related technologies. Session 2 presented Long-Term HHFC Concepts from the US and Japan, primarily aimed toward power plant applications. These components were designed to sustain higher heat and particle fluxes, longer lifetimes, and higher reliability and maintainability requirements. Session 3, Material Aspects for Near Term and Long Term Concepts, examined in more detail regular and ODS steels as well as tungsten. Session 3.1 concentrated on the material development, fabrication, and joining of the high heat flux materials. Section 3.2 examined the plasma-material interface and the testing of high heat flux materials and components. Section 4 presented the physics considerations for the near term and long-term HHFC concepts. In Session 5, Mark Tillack informed the workshop of an evaluation methodology to assess the current technology readiness level, vis-à-vis, the long term objective and how to get there.
The presentations and the summary conclusions and recommendations are being written and will be documented in the near future, probably on the ARIES web site.
Siegfried Malang noted that there were large differences of opinion at the workshop about the number and severity of the disruptions (VDEs and large ELMs) anticipated for a future power plant. Participants associated with present experimental facilities and ITER expressed their opinion that such transients cannot be avoided in a power plant, and that the FW and the divertor targets in such plants must be designed to deal with these severe disruptions.
This led to the suggestion from ITER side that the present design of the ITER divertor target plates could be used in power plants too. This was debated by material people pointing to the big differences between ITER and power plants in regard to neutron fluence and operating temperatures.
Participants more familiar with power plant studies stressed the point that large emphasis has to be given to the development of methods for better plasma control in order to avoid or at least mitigate potentially damaging transients. A power plant with frequent exchanges of damaged plasma facing components would not be acceptable to utilities that require high plant availability and an acceptable refurbishment cost.
Status of Helium-Cooled Divertor Engineering
Xueren Wang is working on the He-cooled divertor to handle high heat and particle fluxes. His design is a plate-type, T-tube and the two-heat-flux zone divertor configurations with both thermal-mechanical and thermal-fluid methods, for both transient and steady-state solutions. His next improvement is to analyze non-uniform heat fluxes over the surface of the divertor plate (probably Gaussian distribution). He is also planning more work on the transient conditions during start up and shutdown. He was trying to determine an appropriate start-up and shut-down time scales.
Attendance at the next US/Japan Reactor Design Workshop (Mar 09)
Mark Tillack said that there are only a few people interested in attending the US/Japan Reactor Workshop to be held in Tokyo, JA, in March 2009. Les Waganer will re-query the team as to their interest in attending.
Involvement of the ARIES Advisory Team
Ken Schultz said that he would like Dale Meade, Farrokh Najmabadi, and himself to have further discussions on the goals for the team and how to better utilize this team. Farrokh and Ken agreed to meet shortly with Dale to further discuss this subject.
Status of Improved ARIES Systems Code
Zoran Dragojlovic got caught up in traffic and was not able to attend the call, but emailed in his contribution toward the improved ARIES Systems Code.
As reported at the last conference call, Zoran is preparing a new Fusion Engineering and Design journal paper on the ARIES systems code. The paper will cover the systems code algorithms in detail and give several example results that best illustrate the code capabilities and summarize current results. Since that call, Zoran has expanded upon the conference paper written for TOFE conference. The outline describes all the components of the systems code and gives several illustrative results. Details are still being added to the outline and paper and Zoran is anticipating completion of the draft by the end of the year.
Regarding the systems data, Zoran is developing a large, high resolution database of systems code results that will include DCLL blanket in addition to the SiC blanket used for ARIES-AT. Both databases will be expanded by scanning the core radiation fraction and the maximum heat flux on divertor. So far, about 70% of the data points with DCLL blanket are completed and he expects to complete them some time next week. After the results are available, he will make the comparison slides.
Zoran acknowledged the contributions to the code and its database. Ron Miller explained the details of the previous code that is used for comparison to the new code. Laila El-Guebaly contributed the radial build and nuclear parameters. Chuck Kessel committed to writing the section on Plasma Physics. Rene Raffray will help write the section on Power cycle. Zoran will rely on the latest Les Waganer's report on costing accounts to form the corresponding section in the paper.