ARIES Documents -- Meetings ArchiveARIES Conference Call, 21 October 2012
Documented by L. Waganer
Les Waganer reminded the team that the next meeting is scheduled for a full day on 26 September and a half-day on 27 September 2012 at the Bethesda Doubletree Hotel. Al Opdenaker has published hotel arrangements for the meeting room and guest rooms. Les Waganer has published the agenda. Several team members have other commitments and cannot attend, but may call in their presentations.
Farrokh Najmabadi told the members that he would like to have the final TOFE papers and presentation viewgraphs for posting on the ARIES website, so please send him the final version or confirm that Farrokh already has the final version.
At the September meeting, Farrokh is planning to discuss the project goals of completing the ACT-1 technical definition by 1 December 2012 so the final report can be completed by 31 December. He wants to document in the September meeting all the issues that remain to be completed to achieve the ACT-1 goals. In addition, he also wants to identify all the remaining efforts to complete the ACT-2 DCLL option definition. Farrokh said he would distribute the definition of the four ACT options so the team would have a consistent naming convention.
ARIES Technical Efforts
Reliability Modeling - Tom Weaver noted that he has been conserving his budget, awaiting the engagement of Dan Driemeyer, who has been occupied on proposals. Dan is expected to be available soon to work on the reliability modeling efforts.
Cost Analysis of ACT-1 Results - Les Waganer reviewed the ACT-1 ASC cost results and noted all the cost accounts were roughly 9% too high. This could be attributed to a coding error in the application of the cost escalation methodology. If this is the case, the fix is a simple correction. Les intends to examine other cost algorithms and present his findings at the meeting.
Plasma Modeling - Alan Turnbull has been looking at the plasma equilibrium data. Since the plasma aspect ratio has changed, new EFIT runs are needed. He intends to have results for the September meeting. He will be calling in rather than attending.
Divertor Plate Modeling - Minami Yoda explained that GT continues to work on FLUENT simulations of the plate divertor thermal-hydraulics; however she does not anticipate any results for the September meeting. The helium test loop has been tested for leaks and for operation at a pressure of 10 MPa, and they are currently modifying their HEMJ test section for use in this loop. They anticipate that this test section will be tested at heat fluxes as great as 4-5 MW/m2.
Power Core Safety - Paul Humrickhouse said he would not be able to attend the September project meeting as he has commitments at the SOFT conference. He said he will distribute his TOFE slides to the ARIES team (which he did do).
He and Farrokh discussed the water-cooling option for the low temperature shield (outside of the vacuum vessel). During a LOFA accident, it is desirable not to have boiling water as it may create uneven heating in the structure, so an adequate supply of water is needed to preclude boiling. Paul thought the volume of water available in the structure was adequate with natural circulation because there is only a small amount of afterheat and a short duration of heating. Arthur Rowcliffe thought the structural material, FS, could work in this temperature range, depending on the extrinsic design factors (size, geometry, etc) and loading conditions.
VV and Shield Structural Materials - Arthur Rowcliffe mentioned ORNL has been developing some conventional 9Cr-low activation steels with good tensile properties at 600-650°C that is comparable to ODS steels. Creep strength is yet to be determined.
Plasma Modeling in the Divertor Region - Tom Rognlien and Marv Rensink been using new MHD equilibrium data provided by Chuck Kessel in August. They are trying to obtain desirable heat and particle solutions with appropriate divertor slot dimensions. They are looking for two types of solutions, namely, 1) fully detached plasmas with heat loads around 5 MW/m2 and 2) partially detached plasmas using a tilted plate as employed in ITER. They have not been successful yet in finding suitable solutions because it is a time-consuming process to generate a sequence of UEDGE runs that start from an existing non-optimal state and incrementally adjust input parameters to achieve the desired solutions.
Power Core Geometry Solutions - Xueren Wang has been working on the CAD definition of the larger ACT-1, a 6.25 m major radius geometry baseline. He has developed most of the CAD definition of the geometry as well as the maintenance features for this case. He is also defining the divertor configurations in concert with Mark Tillack, Marv Rensink and Tom Rognlien as the configuration and dimensions evolve
As there is no baseline geometry for the DCLL blanket power core, Xueren has been doing an initial layout to help visualize the basic design envelope. He will provide some initial layouts at the September meeting.
Nuclear Heating Analysis - Laila El-Guebaly recalled that she provided nuclear heating data for both the SiC and the DCLL blanket designs in her presentations at the January 2012 ARIES project meeting, see meeting agenda for the presentation. Some updating will be necessary due to geometry changes in both designs as well as more noticeable changes in the divertor regions. She intends to provide updated heating data for the SiC design at the September meeting.
Divertor Surface Analysis - Jake Blanchard has been using the provided ELM heating loads to estimate the divertor surface response. He thinks there will be some melting with the current heating conditions. He will have more analysis results to report at the meeting.