ARIES Documents -- Meetings ArchiveARIES Conference Call, 18 June 2013
Documented by L. Waganer
Lester Waganer reminded the Team that the next ARIES project meeting is planned for late September 2013 and he has set up a Doodle date query for preferred date entries.
Les and Mark will set up the next conference call in about a month.
ARIES Technical Efforts
ACT Power Core Design - Xueren Wang was not available for the call, but Mark Tillack reported Xueren's progress as noted by Xueren below.
Systems and Physics Progress - Chuck Kessel mentioned that he has been working on completion of the ACT-1 Physics document that incorporates sections from Alan Turnbull and another from Marv Rensink and Tom Rognlien.
He has also been working to refine and select the baseline ARIES-ACT-2 operating point so the ARIES team can begin to assess the specific parameters. He has been attempting to find major radii machines with less than 9.5 meters and a divertor heat load of ≤ 10 MW/m2. He feels any such machines with a COE within 5% of the minimum COE would be acceptable. He also had been trying to obtain beta values around 3.25, however he may have to increase the maximum toroidal field strength to around 14.5 T to obtain a suitable design point. Mark Tillack noted that Demo presentations at SOFE had adopted high values of H98, in the range of 1.4-1.5. We may want to consider higher values of H98 for ACT-2 as it opens up the design space.
Chuck said that there are so many key variables that it is hard to pick one or two variables to optimize on. Les Waganer suggested that Chuck and Mark should note the ranges of the key variables and then pick one that provides a reasonable set of key parameters and establish this as our baseline to evaluate (soon).
Materials Characterization, Selection, and Documentation - Arthur Rowcliffe discussed with ORNL colleagues his materials contribution to Jake Blanchard's paper on the ARIES divertor, but he remains uncertain how to write the remaining materials subsections. Mark Tillack said he would send Arthur a draft of his paper with some guidance on the scope of the relevant materials subsections.
Arthur commented that it is possible that the tungsten creep equations currently being used to calculate the dimensional changes for the plate divertor may be over-predicting the creep magnitude as these equations were developed in the 1950's to describe the behavior of very thin tungsten wires. A more recent equation developed by A. Purohit, et al., to describe the behavior of tungsten cladding for a space power reactor may be more correct, assuming it covers the appropriate range of temperature and stress regimes. Arthur should send the references to Jake to determine if this equation is applicable.
Divertor Transition Material - Mark Tillack described the recent work of Norajitra (KIT), presented at SOFE, which explored Ta-111 as an alternative thimble material for their finger divertor. This is analogous to the ARIES transition joint, although our joint occurs outside the high heat flux region. We also chose Ta-2.5W instead of T-111 due to concerns over radioactivity of Hf in T-111.
Divertor Experimental Test Results - Minami Yoda said that her documentation of the Georgia Tech experimental results and correlations for the thermal performance of divertors is nearly complete. She plans to include results that show how a higher coolant inlet temperature of 700°C (which would be closer to the operating window for WL10) in the manuscript that she intends to send by the end of June. Georgia Tech continues to work on experiments with their new helium loop with a HEMJ-like test section at higher incident heat flux values.
Power Core Safety Analysis Results - Paul Humrickhouse reported that he has completed many MELCOR model improvements as a result of comments and questions reported in the May ARIES meeting, such as increased surface emissivity. Now the SS structural temperatures appear to be reasonable. He continues to analyze the combined LiPb/He LOFA and water LOCA. Les Waganer suggested Paul double check the draft May meeting minutes regarding the LOCA and LOFA discussions.