Starlite Engineering Group Conference Call

15 November 1995


C. Bathke, L. Bromberg, L. El-Guebaly, S. Herring, S. Jardin, V. D. Lee, R. Miller, F. Najmabadi, D. Steiner, I. Sviatoslavsky, D-K Sze, M. Tillack, L. Waganer

Attachment: Updated Action List


A conference call was held on Wednesday Nov. 15 at 10:30 PST (1:30 EST, 12:30 CST, 11:30 MST). The call-in number is: 314-232-7776.

The Starlite full project conference call is scheduled for 29 November, at the same time and number. F. Najmabadi noted that the letter summarizing the Starlite contributions has been written, B. Dove has preconditioned its arrival, and it has been sent to DOE. F. Najmabadi STRONGLY emphasized that all authors for the status documents must meet their commitments for submission of drafts on time or the project cannot meet its publication deadline. Write-Write-Write!

Mark Tillack reviewed the planned agenda for the CC:

Debriefing by Steve Jardin of his presentation at the Low Aspect Ratio Device Meeting
Review of LAR analysis and documentation
Status of Ferritic Steel Assessment report
Status of Vanadium Assessment report
Review of RS Li/V Design
-- Choice of Aspect Ratio
-- When a new Strawman?
-- Other
Status of Action Items

Debriefing by Steve Jardin On Low Aspect Ratio Meeting

Steve Jardin joined in the call to inform the Engineering Group on his LAR presentation and his interaction with the Low Aspect Ratio (LAR) proponents. Steve commended Bathke, El-Guebaly, and Tillack on the material provided for his presentation. It was a well organized talk with a depth of physics detail, although it was perceived (by the attending group) as not being generally supportive of the LAR concept. Immediately preceding Steve's talk was one given by Ron Stambaugh of GA who presented more optimistic spreadsheet results of a LAR reactor. His physics results indicated higher beta and higher bootstrap current with no edge current required. Hence this resulted in a much lower level of recirculating power and a much smaller reactor (one half the size of our designs). Given the physical size differences, the ohmic losses seemed consistent. S. Jardin offered to work with GA on reconciling the physics differences. It was suggested that our team also offer to continue to work on specific engineering differences. Significant engineering differences noted were the inclusion/exclusion of a shielded center post, acceptable level of and criteria for waste disposal, and method of supporting the center post conductor for stress reduction.

Review of LAR Analyses and Documentation

M. Tillack reviewed the table of contents for the LAR Assessment report. He asked that all task leaders review the TOC for content and make sure they submit draft sections by 1 December. The document approach is to address each major requirement area for a successful power plant. Also include section(s) on describing unique critical issues and their impact. Mike Billone has agreed to write a section on copper properties.

Authors should not do new work - only that which supports writing and documenting the report. We should also maximize the referencing of other supporting material which creates the basis upon which our strawman design is founded, i.e., Culham's and Peng's work.

There was a lot of discussion on whether we need to generate a new strawman. The direction was that we currently have data reflecting two bounding strawman designs, one with an unshielded center post and one with a 30 cm center post shield. This would suffice to analyze the engineering and economic advantages/disadvantages over a range of center post shielding. There are two remaining open questions regarding equilibria with low current drive and revised equilibrium conditions from GA. If either of these prove to be valid, a new strawman may be needed.

The choice of the blanket was discussed. It was decided that the lithium/V blanket should be retained as the baseline although it may not be compatible, at this point, with the overall design approach. These are the reasons:

* This blanket represented a high performance blanket option which would yield optimistic systems code results quickly.

* A compatible, high performance blanket could be designed, given time and effort.

* Complete modeling for lithium/V blanket is available.

* Comparative analysis with advantages/disadvantages of the alternative blanket options will be prepared and included in the report.

Dai-Kai Sze requested that C. Bathke run a parametric analysis as a function of recirculating power. This will be provided to Sze if time permits, and added to the report as additional support to the cost analysis.

Igor Sviatoslavsky reviewed his findings on using a cyrogenically-cooled center post to lower the resistivity and the recirculating power. Magnetoresitivity in copper may limit its application. Aluminum may be possible if properly shielded. Cryogenic heat loads would have to be in the range of 2 MW for the leverage of the cryocooling to be effective. The cost of the cryogenic plant is a factor that may cause this approach to be abandoned. This analysis will be documented for the report. L. Bromberg reported that MIT has considered such an approach but did not know present status or applicable references.

Status of Ferritic Steel Assessment Report

Mark Tillack noted that this report is essentially complete and ready for publication. A draft copy is posted on the Starlite WWW Home Page. M. Billone is planning to complete a material appendix to be included.

Status of Vanadium Assessment Report

Mark Tillack noted that this report is also in draft form and is posted on the Starlite WWW Home Page. After the other reports are finished, this will be reviewed for completeness and editorial changes will be recommended.

Review of RS Li/V Design

In addition to the above documentation efforts, the design for the reverse shear (RS) commercial power plant is advancing. C. Bathke has reviewed his previous strawmen and determined that there is little difference in engineering parameters between the aspect ratios of 3.5 and 4.0 which represent the range of minimal COE. An aspect ratio of 4.5 was somewhat higher in cost. The Engineering Group felt that within the range of 3.5-4.0, selection of the higher aspect ratio would offer a less-restrictive design envelope. Thus it was recommended that the project proceed with a RS aspect ratio of 4.0.

C. Bathke needed definition of the bucking cylinder and the TF cap support structure (to develop the clearance envelopes for the PF coils) to begin the RS strawman. L. Bromberg said to use 24 cm for the thickness of the bucking cylinder and assume the same thickness for the TF cap structure. This would enable the generation of the plasma and TF/PF coil definition. F. Najmabadi recommended using a 5 cm-thick scrape off layer (SOL) be adopted for this generation strawman. [This was ClementÕs comment prior to the call Š FarrokhÕs suggestion for a 5 cm thick SOL is appropriate. Clement will need to contact the Physics Group for the mode of physics at the RS edge, L-mode, H-mode or enhanced H-mode etc., before he can estimate the e-folding distance of the SOL for our design.] The geometry for the A = 4.0 plasma and first wall will be provided to D. Lee on 20 November (Monday). Given this geometry, Dennis Lee can begin definition of clearance envelopes for the piping and manifolds, maintenance provisions, and vacuum ducts. R. Miller will travel to LANL to work with C. Bathke to upgrade the cost algorithms and data in preparation for the next complete strawman.

Status of Action Items

L. Waganer reviewed the completed and outstanding action items. Only the noteworthy comments are highlighted here - see the remainder in the attached updated Action List.

The dates for several action items were delayed. As mentioned earlier, C. Bathke verified his strawman results. A draft Engineering Parameter List has been issued. M. Tillack will check the Starfire and Aries lists for consistency. D. Lee reported that 3-D wireframe IGES files have been successfully transmitted and translated both ways between UCLA's ProEngineer and MDA's Unigraphics CAD systems. He further noted that a parallel test between Sandia and MDA of a transfer/translation of solid models using STEP files is underway. L Bromberg has analyzed the cap structure further but a final answer needs more refinement. For now, 24 cm should be used for the bucking cylinder and a uniform thickness cap. This will allow Bathke to position coils for the generation of the geometry data. L. Waganer forwarded data that C. Kessel provided on the kink and stability shells/coils required. D- K Sze will follow-up with Kessel for more details on how to satisfy the requirements. I. Sviatoslavsky discussed the design difficulties of conducting or structural joints between modules. D-K Sze deferred to C. Wong for the vacuum duct sizes. The transfer of data for stress calculations between ProEngineer and ANSYS codes revealed an incompatible data structure so this will not be pursued.

ACTION ITEM LIST, Ordered by Date.

Responsibility      Action Item                                           Due Date
Bathke              Verify that A=3.5 is optimal and increasing the       31 Oct 95      
                    radial build may be implemented at a modest cost      [Completed]    
Waganer             Realign the Mission Statement                         22 Nov 95   
Najmabadi           Define the schedule and the near-term milestones      22 Nov 95   
                    for the restructured Starlite program.                        
Sze                 Review the Prometheus final report to determine if    22 Nov 95   
                    any figures can be modified                                   
Waganer, Tillack    Establish an engineering parameter list to define     22 Nov 95  
                    the technical baseline. [Draft issued, Tillack to             
                    compare w/Starfire and ARIES lists.]                                 
Wang, Lee           Confirm ability to transfer CAD files between         22 Nov 95  
                    ProEngineer and Unigraphics [Done.  Solid modeling            
                    transfer in process with Sandia.]                                    
Wong                Estimate pressure requirement in the divertor slots   15 Dec 95  
El-Guebaly          Provide FWBS heat loads for thermal-hydraulic         15 Dec 95   
Sze                 Define the header and manifold sizes and locations    22 Nov 95   
                    for the FWBS and divertor regions and forward to D.           
Sze                 Recommend OB coolant flow direction to accommodate    22 Nov 95  
                    drainage and passive convective flow                          
Bromberg            Revise cap structure and re-analyze stresses and      22 Nov 95  
                    send to Lee.  Provide guidance to Bathke regarding            
                    the necessary clearance between the TF and the PF                    
                    coils for the cap structure                                          
Kessel              Define the physical properties of the conducting      22 Nov 95  
                    shell (material, thickness, area coverage,                    
                    conductivity, and continuity in poloidal and                         
                    toroidal directions.[Defined Kink and Stability                      
                    Requirement.  Sze to contact Kessel for further                      
Sviatoslavsky       Develop an attachment scheme to provide a             15 Dec 95  
                    structural conducting shell nominally at the                  
                    reflector location.[11/15 presented design                           
                    difficulties, still working on solution.]                            
Blanchard           Finish assessment of the EM load modeling. [Have      15 Jan 95  
                    one commercial code, awaiting a European code.]               
D. Lee              Modify penetrations to eliminate direct line of       15 Dec 95  
                    sight and include right angle turns. [Incorporate             
                    as part of final design.]                                            
Bathke              Relocate and/or reshape PF coils. The innermost PF    22 Nov 95      
                    coils may also be reshaped to reduce the overall                     
                    major radius. [Interim input data assumed.]                          
Ehst                Conduct a thermal erosion calculation on the          15 Dec 95  
                    divertor due to "giant Elms". [Coordinate with                
                    Hassanein item below.]                                               
Wang                Transfer ProEngineer output to ANSYS                  xx Nov 95      
                    code.[ProEngineer outputs incompatible with stress    [Closed]       
                    model - close AI.]                                                   
Najmabadi,          Oversee the format, editing, and publication of the   1 Dec 95       
Tillack, and        Annual Report.  Critical schedule milestones should                  
Miller              be identified for authors if required [Need inputs                   
                    from authors to meet goal.]                                          
Wong                Define the SOL e-folding distance and evaluate the    1 Dec 95 ?     
                    impact to the divertor design.  Forward  data to                     
                    Bathke to define a new first wall flux line to be 4                  
                    e-folding distances from the separatrix. [Interim                    
                    assumption of 5 cm should be used, pending                           
Wong                Recommend the vacuum duct sizes to be employed in     1 Dec 95       
                    the divertor region                                                  
D. Lee              Revise the configuration to include FWBS, divertor,   1 Dec 95       
                    vacuum vessel, coils, and plumbing.  Penetrations                    
                    and segmentation of the FWBS and divertor are to be                  
D. Lee              Provide IB and OB surface areas and divertor volume   1 Dec 95       
                    on the new configuration                                             
B.J. Lee            Revise Te-stagnant calculation and make sure that     1 Dec 95       
                    energy and particles are conserved in the SOL.                       
                    Include detailed momentum equations for impurities                   
                    to benchmark DIII-Ds experimental results with                       
                    injection of deuterium.  Use particle and heat                       
                    fluxes in place of point inputs of temperature and                   
El-Guebaly          Determine effect of conducting shell on breeding      15 Dec 95      
                    and shielding                                                        
Hassanein           Evaluate erosion of a bare vanadium wall and add to   15 Dec 95  
                    existing set of data for Be and V.  [Coordinate               
                    with Ehst task above.]