ARIES Documents -- Meetings ArchiveARIES Conference Call, 9 February 2000
Documented by L. Waganer
(UCSD) Baker, Mau, Miller, Najmabadi, Raffray, Tillack, Wang
(PPPL) T. Brown, Heitzenroeder, Dahlgren
(GA) Chan, Lau
(UW) El-Guebaly, Mogahed
The next ARIES conference call is scheduled for March 1 from 9:05-12 PST.
Farrokh Najmabadi elaborated on the plans for the US/JA Reactor Design Workshop to be held in San Diego on March 16-18 (Thursday-Saturday). It will be held at the Institute of the Americas. Ron Miller has created a Web site, <http://aries.ucsd.edu/~miller/MTG03/>, with the agenda and more meeting details. The IEA Socio-Economic Task results might be reported at this same meeting.
The ARIES meeting will start on Monday, March 20, and continue through the end of the day March 22.
The Presidential budget is out and our design study budget is similar to that of last year. There will be an effort on IFE work, with some minor budget remaining for MFE work. Details on the study effort have not been defined at this point.
Rene Raffray reported on the SiC Workshop held at ORNL in January. Participants were from Japan, EU, and the US. The ARIES Web site has a link to two presentations from the workshop. Japan presented a summary table showing properties proposed for usage in advanced design studies; they were similar to those used in our study. Japan and EU seem to have larger SiC programs than the US. Japan is concentrating on high quality fibers to yield better properties. They are planning to irradiate some samples shortly.
The cost of SiC composite is now very high, but the general opinion was that higher production rates would bring the fabricated cost down to the range of $400/kg and the bulk cost to $100/kg.
The joining technique is generally thought to be brazing. EU has been doing a lot of brazing work. The composition of the braze is proprietary.
Mark Tillack noted that the methodology of stress allowables and lifetime are completely different than that for metallics.
Neutron Source Study
Bill Stacey and Don Steiner addressed FESAC early in February on the subject of "burning" nuclear waste in accelerator, fission, and fusion systems. Bills talk was based on his recent paper on this subject. Charlie Baker thought Dons talk was very good and addressed the broad aspects of transmutation with fusion neutron sources. Charlie thought there would be not immediate action on this subject.
Don said he is trying to complete the neutron source study. If you have any comments to the summary he sent out, he will incorporate them. He will try to have the final report in two months.
Ron said he was overdue publishing the new strawman. He has input three baseline physics cases, with betaN of 5.6, 6.0, and 6.8, along with three current drive cases scaling with Zeff and Te. The code is running cases with finite edge densities of 8% to 11%. He as posted the three cases on the web. However, he is continuing to debug the physics routines. There is no data on the divertor yet. Farrokh mentioned the use of a liquid metal divertor surface in conjunction with the ALPS study.
Ron said that until he checks out the systems code, he is using the NbSn superconducting magnets. After he is sure it is working correctly, he will incorporate the high temperature superconducting magnets.
So the three cases are only representative at present. The geometry is not correct or final.
Vincent Chan is working on three tasks: optimized high kappa cases, assessing non-ideal modes, and neo-classical modes. (Vincent, I was not able to take good enough notes to follow your discussion. Would you please expand on this?)
Steve Jardin noted that all requested information has been provided to Ron and his code. Ron noted there is still some conflict with the JSolver and PF coil locations. Ron asked Steve if PPPL could generate a set of approximate PF coil locations for initial code starting points.
TK Mau said that he did provide Ron with the CD scaling algorithms for three cases. Parameters are Te and Zeff from 1.6 to 2.0. He is considering FW on axis CD and LH for off axis. He has achieved good matching and alignment. The normal bootstrap fraction is around 94-98%. If LH is used at high edge density, it results in poor system efficiency. May also need NB for off-axis CD.
Configuration and Maintenance
Mark said they are working on the configuration, especially the routing of the coolant into the blanket and divertor. They are trying to not make any connections inside the vacuum vessel. Les Waganer said to look at his sketch of the vacuum vessel and door. It illustrates a plumbing connection inside the vacuum vessel that can be verified before the door is closed. Mark has since examined the drawing and thinks this approach might be used.
Mark summarized that the coolant routing on the Malang blanket approach may be more difficult than previously thought. The difficulty is meeting all the requirements imposed on the coolant system and still keep it simple.
Neutronics and Shielding
Laila noted that the new FENDL2 library is now being used in the neutronic analyses. No major changes or impacts were found. She has completed the analysis of the Malang blanket and the results are similar to previous results. Since it does have more SiC content, it is more expensive. She does have preliminary divertor data and is working on the divertor shield. She is working with Ron on the requirements for the high temperature S/C shielding.
Ron said that he does have the poloidal distribution of the neutron wall loading for Lailas analysis. It is lower than ARIES RS due to the increased thermal conversion efficiency.
Heating and Current Drive
TK reiterated that he is planning to use FW on axis and LH and NB off axis. Surface areas, locations, and materials to be used should be given to Laila for her analyses.
PF and TF Magnets
The location of the PF and TF (and shape of TF) should be similar to those of ARIES-RS for the first iteration. The need for an inboard divertor is still to be determined.
Les Waganer had created a simplified vacuum vessel that combined the vacuum vessel with the low temperature, inboard shield. This should help reduce the cost of this large component. The figure is accessible from the ARIES web site. Laila noted that the joints that are to be rewelded must have increased shielding to meet rewelding criteria.
Rene Raffray presented his current SiC baseline blanket at the SiC workshop. He is working with Mark to help integrate the design into the power core. He is now working on the thermal analysis and hopes to have that completed by the March meeting.
A crucial analysis is the modeling of the MHT and inertial effect of the high velocity coolant stream in the front face channel. It was hoped that Dr. Molotov of ANL could help, but D.K. Sze indicated that he would not be available to help on this assessment.
Fuel Cycle System and Main Heat Transfer and Transport System
Dai Kai has been talking with Steve Zinkle about determining the enrichment cost of Li.
Dai Kai is working on the tritium recovery system definition and assessment. A gas purge system is the favored one at present.
Vertical Stabilizing Shell
Laila and others discussed the current status. At present, it is likely to be a thin copper shell, cooled with helium to less than 700°C. If the operating or accident temperature may exceed 1100°C, then the copper will be clad in tungsten? (I was not sure I heard a recommended clad material.)
Laila has not yet included the stabilizing shell in the activation analysis (awaiting a firm decision on size and materials.) Now she has completed both the inboard and outboard regions in the analysis. She is generating data on clearance indices. All components are greater than one. Could meet a clearance of one with added shielding. It was noted that we should trade off the cost of getting components cleared or not cleared. Laila is planning to send data to Dave Petti within a week.
Safety and Waste Management
Dave Petti reiterated the desirability to conduct a trade study on the clearing of the magnets. We also need to more thoroughly examine our optimization criteria for these reactor designs.
Also the silver in the high temperature magnets is a problem for the waste disposal rating/clearance.