Meeting 3 Action Items
The following action items were agreed upon during the workshop:
(1) The next APEX meeting will be held in Albuquerque , New Mexico, July 27-28, 1998. Plasma interface issues and plasma confinement concepts will be held July 29, 1998 followed by the ALPS meeting, scheduled July 30-31, 1998, in the same place.
(2) The reference values for the (peak) neutron wall load (NWL) and the surface heat (SHF) have changed for any proposed to be 10 MW/m2 and 2 MW/m2, respectively. Additional measure of very high potential of NWL = 20 MW/m2 and SHF = 4 MW/m2 is encouraged, if feasible.
(3) Some of the proposed HPD concepts where either abandoned from last meeting (e.g. Heat pipe, Mist flow) or put on hold during this meeting (Porous Wall). In the latter case, recent analysis has indicated that the stress and temperature limits of SiC, for example, could be exceeded based on the current data under high NWL. The consensus of the attendees was to hold the filtrated porous wall concept for the time being. Other concepts that will be pursued are, the thin Convective thin wall concept, the thick liquid wall (free fall and magnetically restrained) concept, the free fall Li2O Particulates with no structural FW concept, and the helium-cooled solid refractory FW concept. The vaporization concept presented by Malang (FZK) was encouraged to be evaluated in-depth. people who indicated their interest to work on this concept are: Mattas (ANL). Tillack (UCSD), Nelson, Berry (ORNL), Morley, Youssef (UCLA), and Malang (FZK).
(4) Steady state operation in Tokamaks is the reference point. Advanced Tokamak , ARIES-RS, general parameters will be adopted in the study. Open systems such FRC/Spheromak will also be considered as an alternative confinement system. Ralph Moir (LLNL) will (or find a physicist to) get configuration and boundary conditions of such systems. (Suggested person is A. Hoffman, U. Washington). It was a greed to devote time during the next APEX meeting to discuss configuration and parameters of Stellerators (1hr) and FRC (1hr). Meade will look into this arrangement.
(5) Malang (FZK) outlined the minimum required information for each concept. These requirements were officially distributed by Abdou along with the milestones for the APEX study. (see Sections VI, V, and VI). Abdou requested that the lead person of each concept to submit to APEX management by June 15 the crucial issues pertaining to the concept to be addressed during the coming 8 months, the new models, codes or experiments that are required to investigate these crucial issues, and the needed resources (analysis and experiments) over specified length of time to investigate these feasibility issues.
(6) A Steering Committee to be formed from people (5-6) who can best judge, evaluate, and possibly prioritize the proposed concepts based on their expertise and who attend, when possible, all APEX meetings.
Other items are:
(7) Specific calculations and design data on Helium-cooled refractory structural FW concept was promised (Wong) for the next meeting in ABQ.
(8) The configuration of penetrations for heating and diagnostics is not known, so a generic 1 m^2 opening should be developed for each concept.
(9) The Mechanical group (Nelson) proposed a meeting at UCLA for the week of June 15 or June 22 to further develop the liquid FW concept.
(10) From the Materials Session, the values used for costs of several of the materials presented by Ghoniem appeared to be inaccurate and much too high (several). He will check these data. Other data to be checked are: Nb-1Zr in range of 700-1000°C (Ghoniem), Al2O3 coating on Ta (suggested by Wong), using 304SS with flibe (suggested by Moir). Sze suggested raising the operating temperature limit of interest for from 650°C max. to 1000° C. This action was accepted.