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 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 analysis Sze Define the header and manifold sizes and locations 22 Nov 95 for the FWBS and divertor regions and forward to D. Lee 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 definition.] 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 analysis.] 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 included. 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 density. 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.]