Progress of ARIES Systems Code Development

1. Progress of ARIES Systems Code Development Zoran Dragojlovic A. René Raffray Farrokh Najmabadi ARIES-“TNS” Project Meeting June 14 and 15, 2007 General Atomics, La Jolla CA

2. Progress Overview • Previous Work • Realistic 3-D geometry of ARIES-AT Tokamak generated, while using plasma parameters and inboard radial builds as input data. • Power flow incorporated, with the input based on an external physics code provided by Chuck Kessel. • Tested geometry and power flow scheme by comparison with ARIES-AT data. As a test run, generated geometries and power flows for 120 physics operating points, which had passed the engineering filters. • New Accomplishments • Adopted a new object-oriented algorithm and replaced the previously written Fortran code with C++. The new algorithm allows modular programming, where generic building blocks can be re-used many times and in different combinations. • Costing algorithms included. • Achieved a reasonable agreement with previously published ARIES-AT data. • Included Les Waganer’s updates for accounts 20 and 21. • Cost of Electricity obtained. • Agrees within 2-3% with the published ARIES-AT value. • Generated contour maps of COE for 1,452 data points provided by Chuck Kessel. The contour maps are generated in several different 2-D planes in order to demonstrate potential control knobs for the cost of electricity. • Engineering Algorithms are in Progress • Include the engineering limits in order to calculate radial and axial builds. Currently inboard radial builds are taken as an input and remaining builds and outboard/axial builds are scaled to match ARIES-AT. • Incorporate the magnet algorithms in collaboration with Leslie Bromberg.

3. ARIES Systems Code Class DesignPoint {data; functions that operate on data;}; • Foundation for the algorithm is a general-purpose systems analysis toolbox. • Consists of ready-to-use generic objects (classes) that serve as building blocks for different systems algorithms with different objectives. • Class DesignPoint holds design-specific data that describe the entire machine, such as plasma parameters, builds, power flow, building volumes, etc. These data are accessed, operated on and displayed by special functions that belong to the same class. • Class Part holds part-specific data such as contours, areas, volumes, etc. • Class CostingAccount holds the costing account structure for the selected machine design. • Simple declaration statement such as “Part Blanket_II;” declares all the arrays and single-valued variables needed to define this particular object. • Systems Code is generated by connecting the elements of the toolbox together. Class Part {data; functions;}; Class CostingAccount {data; Functions; };

4. Systems Analysis Algorithm Part First_Wall_Inboard; Costing Algorithms Part PFCoil[29]; Geometry COE 2 3 Part Blanket_II; DesignPoint Aries_AT; Aries_AT.get_physics(); Aries_AT.get_builds(); • An example configuration that calculates the cost of electricity for ARIES-AT is simple and straightforward. • Once the objects are well defined, they can be used to build many different codes. Display Output Aries_AT.show(); Input Data physics parameters radial builds 1 4

5. Geometry Different Arbitrary Configurations are Easy to Assemble Configuration 1 Configuration 2 Blanket A Blanket B Geom. Blanket C ARIES AT Costing Costing Algorithms ARIES SPPS Geom. Costing Input Data Starfire Geom. • Configuration 1: different design points can be run together, at the same time, in case they need to share/exchange any information during the run. • Configuration 2: different parts or costing accounts can be plugged in and out as the code runs. Costing Output ARIES-TNS Prometheus -L Geom. Costing

6. Costing Algorithm • At recommendation from Ronald Miller, forwarded by Laila El-Guebaly, costing algorithms were based on an unpublished Chapter 2: System Study of the ARIES II-IV report. A copy is available upon request. • After the algorithms were implemented, the new code was validated by comparing the results to the data published in the ARIES-AT design book. The cost base for these data is from 1992 and the case with LSA=4 was selected. • New values of Total Direct Cost (TDC) and Total Capital Cost (TCC) differ from published data by 10.7% each .Cost of Electricity (COE) estimated by the new code differs from the previous data by 1.64%.

7. Side-By-Side Comparison of Costing Accounts for ARIES-AT Questions: • Account 22.1.5 Primary Structure and Support uses Vstr volume which I am not sure where to get from. • Account 22.1.7 Power Supply uses a formula in terms of $/kVA. Where does the “kVA” come from?

8. Side-By-Side Comparison of Costing Accounts for ARIES-AT • Account 22.2.0 Main Heat Transfer System uses straightforward formulas which are dependent on thermal power PTH. No idea where the discrepancy comes from.

9. Side-By-Side Comparison of Costing Accounts for ARIES-AT • Accounts 90 through 99 are proportional to the sum of the costs defined by the accounts 20 – 26, therefore they propagate the same cumulative error of 10.69%. • With the few exceptions, the new code provided a reasonable match with the existing ARIES-AT data.

10. Comparison Between ARIES-AT and ARIES-TNS for Cost Base of 2007 • Accounts 20 and 21 for ARIES-TNS were updated by Les Waganer, who will provide a more detailed information in his talk.

11. Comparison Between ARIES-AT and ARIES-TNS for Cost Base of 2007 New accounts 20 and 21 did not significantly impact the cost of electricity.

12. Contour Maps of Cost of Electricity Versus Several Selected Parameters • The data for this test was provided by Charles Kessel, PPPL. • Generated a large number of physics operating points close to ARIES-AT specs. • All the viable points were filtered through engineering limits, which are: • First wall heat flux. • Divertor peak heat flux. • TF and PF coils • peak field limit and superconducting current density limit. • Bucking cylinder criteria. • This resulted in an inboard radial build with assumed thicknesses for the First Wall, Blanket, Shield, and Vacuum Vessel from ARIES-AT neutronics analysis. • Final outcome: 1,452 surviving data points were provided as an input to the new ARIES Systems Code. • The new systems code estimated the cost of electricity for all the data points in 2 hours of CPU time. The data was used to generate several contour maps. • COE was plotted against several pairs of parameters, at Chuck’s suggestion: • Toroidal field BT and plasma major radius R. • Bootstrap fraction and bn. • Power density and plasma major radius R.

13. 65 70 75 80 85 [mill/kWeh] Cost of Electricity Versus Toroidal Field and Plasma Major Radius Lower Limit of COE Upper Limit of COE (5.5, 6.0) (5.5, 6.0) • For each pair of coordinates (BT, R), there was a small variation (< 8 mill/kWeh) of COE within the same “geometrical” point. The lower limit of that variation was shown on the left, while the upper limit was shown on the right. • COE increases with toroidal field and plasma major radius, as expected. • The dependence of COE on BT is higher for larger radius R.

14. 65 70 75 80 85 [mill/kWeh] Cost of Electricity Versus Bootstrap Fraction and bn Lower Limit of COE Upper Limit of COE • Data implies that the cost of electricity depends only on the bootstrap fraction.

15. 65 70 75 80 85 [mill/kWeh] Cost of Electricity Versus Power Density Pdiv,cond/R and Plasma Major Radius Lower Limit of COE Upper Limit of COE • Power density is based on the power conducted in the divertor divided by the plasma major radius. • In the space of these two parameters, the COE behaves as expected.

16. 65 70 75 80 85 [mill/kWeh] Cost of Electricity Versus Power Density Pdiv,cond/R2 and Plasma Major Radius Lower Limit of COE Upper Limit of COE • Power density is based on the power conducted in the divertor divided by the plasma major radius squared. • P/R2 tends to over-emphasize the effect of radius, compared to P/R shown in the previous slide.

17. 8 7 6 5 4 3 2 1 0 Local Variation of COE Across the Planes of Different Parameters [mill/kWeh] • Local variation of COE is obtained by subtracting the lower from the upper limit at each “geometrical” point. • In the plane defined by power density Pdiv,cond/R and plasma major radius R, variation of COE at each point is almost negligible, which indicates that these two parameters might be the strongest knobs of impact on the COE.

18. Action Items

19. Discussion and Conclusions • ARIES Systems Code development is on the schedule. • Costing algorithms are fully implemented by June 2007, as promised at the last meeting. • Cost of electricity is now within few percents from the existing ARIES-AT data. More tests are possible and can be accomplished within a month, if needed. • Engineering algorithms will be implemented in order to make the code ready for the ARIES-TNS study by August 30, possibly earlier. • Object-oriented programming style was adopted since the last meeting, in order to make the code modular and more flexible with respect to different objectives of the system study. • Data visualization is undergoing development, in order to provide an insight into trends of the cost of electricity and help to optimize the power plant. • COE contour maps were plotted against several different parameters, such as major plasma radius, power density, bootstrap fraction, toroidal field and bn. • Data included in this analysis imply that there could be a pair of strong knobs that control the COE, such as plasma major radius and power density, for example. A better resolution and more accurate calculations will be done to test this finding.

20. Acknowledgement to Co-Workers – Thanks!