ARIES Documents -- Meetings ArchiveARIES Conference Call, 23 April 2012
Documented by L. Waganer
Farrokh Najmabadi scheduled the next ARIES meeting be held in the Washington, DC area on Thursday, May 31st and half a day on Friday, June 1, as these dates were deemed best for the team. This date is also suitable to Al Opdenaker as he will be making the meeting room and hotel arrangements, probably at the Gaithersburg Hilton.
The next phone call should be held in third week of May before the 28-29 May project meeting. Les Waganer will set up a Doodle query on available dates.
New Charge for FESAC - Dale Meade mentioned that W. F. Brinkman, Director of Office of Science, asked FEASC to quickly assess research priorities (non-ITER) among and within the MFE Science Program for the next decade, FESAC Charge. This will be challenging as the ITER budget is a significant fraction of the proposed and anticipated OFES budgets for the remainder of the decade.
ARIES Technical Efforts
Radial Build Progress - Laila El-Guebaly said the radial build is progressing and the inboard region for the DCLL model is quite similar to the ARIES-AT version with a difference of only 6 cm. The IB VV is about 5-cm thick and has been moved inboard (toward the plasma) in front of the lower temperature water-cooled shield with WC filler. She thought the inboard TF magnet should be moved inward the accommodate the slightly thicker radial build and the magnetic field might have to increase, but the Systems Code would determine the required field strength.
Laila noted the TBR for the SiC concept seems to be adequate. This concept has a vertically-straight (not curved) inboard first wall. She will be completing the neutronic analysis on this concept before the meeting. She is conferring with Xueren Wang and Mark Tillack on the design and geometry of the upper and lower divertor regions to improve the model fidelity.
Divertor Experimental Results - Minami Yoda said that the experimental results for the thermal performance of the modular finger-type divertor with and without fins have been correlated with numerical assessments for air, helium and argon. She has been conferring with Mark Tillack on these correlations, and plans to present these results at the next ARIES meeting.
Safety Analysis Progress - Paul Humrickhouse is combining the previous safety models of the LiPb and the He/water blanket concepts for analysis of the upcoming ACT design concepts. Hopefully, he can provide more information at the upcoming meeting.
Materials Developments - Arthur Rowcliffe confided he is having difficulty gathering valid and complete materials databases for the fusion materials of interest. Specifically, he is trying to obtain relevant data on the new 3Cr-3WV reduced activation steel. The difficulty is that the petro-chemical industry is modifying this material by adding about 0.7 wt% of molybdenum, which would be unattractive for the fusion application. However, Arthur believes the addition of Mo would not significantly change the physical properties of the material. Laila said the 0.7 wt% Mo will make the 3Cr-3WV steel more radioactive and may not qualify for low-level waste.
Arthur requested Laila to send him the neutron spectrum and dpa level expected at the LT-shield application.
Divertor Design and Analysis - Mark Tillack and Xueren Wang are refining the upper and lower divertor regions to integrate the proper surface shape, shielding, breeding and manifolding within a confined region. The lower, inner divertor is the most restrictive area with the larger coolant and manifold piping sizes. They may use the steel ring structure to obtain the proper shielding in local areas. If the TBR is adequate, the breeding requirement in the divertor region may be relaxed. Mark intends to have preliminary designs by the next meeting.
Preliminary Power Core Design - Xueren Wang has been working with Laila, Chuck, Siegfried and Mark to define and design the preliminary power core designs for the two concepts. He is using the most recent inboard radial build issued by Laila along with the divertor definition to prepare two preliminary designs. He mentioned that these designs will evolve as the analyses and the Systems Code results become available. However, these preliminary designs are useful to understand the functionality and integration of the power core components.
Thermal Creep Analysis of the Divertor - Jake Blanchard described his continuing analysis of the tungsten elements on the divertor plates. He is finding the analysis more complicated and more of a design challenge than originally thought. He is finding a noteworthy amount of creep in the notch area and also on the inside of the coolant chamber. He will run the full analysis to determine how the divertor fails due to thermal creep. He has not completed the analysis, but will have results for his meeting presentation.
He is also beginning the modeling and analysis of the VV with ribs to determine fracture conditions.
Reliability Modeling of the Divertor Components - Tom Weaver stated that Boeing is now under contract. They are in the process of adding the physical parameters into the existing performance code to get the divertor lifespan and failure mode. He has been in contact with Tom Rognlien and Mark Tillack on the parameter sets relating to surface heating and ELMs with excitation frequencies from 1-5 Hz.
Tom expects Dan Driemeyer, of Boeing, to begin evaluation of power core structural elements. Dan was the US ITER Divertor Design and Development Team Leader in the late 1990s.