The group affirmed the Madison meeting dates to be 17-18 June (full days on Tuesday and Wednesday). It has been suggested that Monday, 16 June be devoted to a town meeting, highlighting guidelines and rules for designing reactor components with brittle materials. Tillack, Sze, and El-Guebaly will coordinate the town meeting agenda and presenters (e.g., Zinkle, Klueh, Billone (or alternate), Majumdar, et al. Coordinate with Wiffen?). There is no separate physics group meeting planned, but TK Mau (and Bob Miller of GA?) wanted to meet with Prof. Ray Fonck to discuss the Pegasus design and systems - others are welcome to join them during Monday afternoon.
Highlights of the recent ISFNT-4 at Tokyo were noted by L. Waganer in the CC agenda. M. Tillack volunteered to install all ARIES-related ISFNT-4 technical pre-print papers on the ARIES Web site and to print the collection as a UCSD report, as with previous collections. Please send him your most current version.
M. Tillack also mentioned he is trying to alter the TBWG meeting date or location to enable ARIES members to attend the October IEEE/SOFE symposium.
Ron Stambaugh said that Bob Miller of GA will be handling the GA plasma modeling. He will specifically look at the finite edge pressure gradient (p') and radiating mantle. Ron Stambaugh noted a general trend of the physics models to prefer the higher aspect ratios (A), up to 1.6 and higher. He noted that this trend may impose engineering limits involving the tritium breeding ratio (TBR) and the power loss associated with the center column (when will it be necessary to add a functional blanket to the center column?) The code should be able to generate the blanket surface area for any aspect ratio. F. Najmabadi noted that the relationship of the TBR to the aspect ratio is not monotonic, but rather depends on the blanket concept. (The inherently higher TBR of a liquid lithium blanket is more forgiving regarding blanket coverage.) Also, we should be careful to note that CHI is not necessarily required. The group also noted there is no consensus for the required level of TBR for a commercial plant - many factors remain to be quantified and verified including the relationship between the 1-D and 3-D modeling. L. El-Guebaly, with support from Ron Miller, will try to do an aspect ratio trade study for the overall TBR and energy multiplication for the outboard and inboard regions.
Steve Jardin said that most of the ARIES physics group are working toward the documentation of the FED paper. They are also working on the figure of merit paper, being led by TK Mau. There is new data from the START experiment which will be added to the paper. On the new tasks, the ST plasma data is to be examined with plasmas having elongations of 3 to 3.5 and aspect ratios of 1.4 to 1.6. These will be examined with various divertor geometries and scrape off thicknesses. Steve noted that in the last TFTR runs krypton impurities were used with higher radiated power in the mantle without affecting the energy confinement time.
It was reported by Dai-Kai Sze that Martin Peng said that no (vertical) stability shell is needed in a LAR or ST plasma. Steve Jardin said that this was true below certain beta values; but, in plasmas of interest, the shells would be needed. Steve will confer with Martin to resolve this issue. M. Tillack subsequently noted that the Engineering Group is waiting for the Physics Group to define the engineering requirements for stability (location and conductance of the LAR/ST active and passive stability systems) for incorporation into the blanket design and overall configuration.
IBC Centerpost - Wayne Reiersen said that most of the IBC information was contained in the prior discussion. It was noted that the larger IBC power supplies would be a significant cost item that would warrant some scrutiny in the cost accounting.
Nuclear Aspects - Laila El-Guebaly said that the 3-D modeling is currently based on the 2-year-old ST design. She needs a new definition of the blanket design from D-K Sze (breeding material and coolant). She noted that there is a new ORNL-developed ferritic steel (ORNL 9Cr-2WVTa) that is more radiation resistant than the Japanese F82H ferritic steel, per R. Klueh. The ORNL steel will be used for the ST design as the main structural material.
First Wall/Blanket and Thermal Conversion - Dai-Kai Sze noted that the
LAR has a severe FW limitation, which eliminates most "conventional" first wall
and blanket designs. He and S. Malang have been working to define two
blanket options that may offer a solution.
Safety Analyses - H. Khater reported he is updating their code to use FENDL-2 in place of the older FENDL-1. They still need the INEL volatility data to determine the release data from the CP LOCA analyses; Tillack volunteered to intercede, if needed.
High Heat Flux Components - UCSD is looking at a liquid metal HHF system to determine if various configurations would be applicable in the ST application.
Configuration and Maintenance - Mark Tillack mentioned that they are comparing several configuration options, especially trying to make a relative comparison between horizontal and vertical maintenance. One interesting option is to rotate the machine axis to a horizontal plane so that the (previous) vertical maintenance could be done cheaper and more efficiently in a horizontal plane.