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50 cm 25 cm The Dynomak Reactor System D.A. Sutherland, T.R. Jarboe, and the HIT-SI Team University of Washington, Seattle, WA, USA 55 th Annual American Physical Society — Division of Plasma Physics Conference, Denver, CO, USA Dynomak reactor system is economically competitive with conventional power sources • The cost of this reactor system was determined via scalings from the HIT-SI device, ITER developed and priced components, and estimates for secondary cycles from fission reactor studies. • The total overnight capital cost was determined to be ~$2.7 billion. • The overnight capital cost of this reactor system undercuts fission and is on par with coal fire power plants. • The first-wall is made of relatively cheap materials, and coupled with a liquid blanket system, provides reasonable maintenance costs that will be assessed more rigorously in future work. Subsystem Cost ($M) Land and land rights 17.7 Structures and site facilities 424.3 Reactor structural supports 45.0 First wall and blanket 60.0 ZrH 2 neutron shielding 267.3 IDCD and feedback systems 38.0 Copper flux exclusion coils 38.5 Pumping and fueling systems 91.7 Tritium processing plant 154.0 Biological containment 50.0 YBCO superconducting coil set 216.0 Supercritical CO 2 cycle 293.0 Unit direct cost 1696 Construction services and equipment 288 Home office engineering and services 132 Field office engineering and services 132 Owner’s cost 465 Unit overnight capital cost 2713 Dynomak Reactor Design Point Parameter Value Major radius [m] 3.75 Aspect ratio 1.5 Toroidal I p [MA] 41.7 Number density [10 20 m -3 ] 1.5 Wall-averaged β [%] 16.6 Peak T e [keV] 20.0 Neutron wall loading [MW m -2 ] 4.2 Current drive power [MW] 58.5 Blanket flow rate [m 3 s -1 ] 5.2 Thermal power [MW] 2486 Electrical power [MW] 1000 Thermal efficiency [%] > 45 Global efficiency [%] > 40 Gas injection system ITER developed cryopumps Helicity injectors and copper exclusion coils Dual-chambered FLiBe blanket system YBCO SC coils ZrH 2 neutron shielding Imposed-dynamo current drive and superconducting magnets enable an energy efficient spheromak reactor system • Imposed-Dynamo Current Drive (IDCD) perturbs and sustains a stable spheromak equilibrium, avoiding severe confinement quality limitations apparent in previous dynamo-driven experiments. • Local pressure driven interchange enables current penetration while allowing thermal power and helium ash to be exhausted. Global confinement quality is preserved. • Six inductive helicity injectors on the outboard midplane provide the necessary edge currents and magnetic fluctuations (δB/B ~ 10 -4 ) for current drive. • An enhanced Grad-Shafranov equilibrium code imposed marginal Mercier stability on each flux surface with λa = 2.4 with an aspect ratio of 1.5. • A highly-dimpled flux conserver enables high wall-averaged β of 16.6%. • YBCO SC was used for the equilibrium coil set with sub-cooled liquid nitrogen. • Twelve, ITER-developed cryopumps connected to pumping manifold were used to limit the helium concentration to 3%. • An insulating break on the geometric axis classifies this device as a spheromak. Coil Set MA-turns A -16.3 B -5.2 C 0.4 D -11.0 E 16.8 F 2.6 β wall [%] Major Radius [m] Z [m] Dynomak reactor system highlights • Imposed-dynamo current drive (IDCD) and a superconducting coil set enables an energy efficient reactor system. • An immersive molten-salt blanket system allows for sufficient tritium breeding ratio (TBR) and unified, single working fluid design. • A supercritical carbon dioxide secondary cycle allows for high thermal efficiency with small physical footprint. • The dynomak reactor system overnight capital cost is competitive with conventional power sources. Dynomak reactor system is most attractive of all recently designed Pilot/DEMO concepts • Use of superconductors in a compact design enables a low recirculating power fraction when compared to an ST, which is attractive for power plant considerations. • IDCD enables energy efficient current drive when compared to conventional current drive methods, further reducing the recirculating power fraction. • Highest neutron wall loading and FLiBe blanket offers most attractive blanket power density, which is also an economic metric for power plant considerations. Parameters Compact Stellarator 1 Tokamak 1 Spherical Tokamak 1 Dynomak Reactor R [m] 7.1 6.0 3.2 3.75 A = R/a 4.5 4.0 1.7 1.5 I p [MA] 3.3 11.6 26.2 41.7 P fusion [MW] 1794 2077 2290 1953 P aux [MW] 18 100 60 58.5 Q p - Plasma 100 20.8 38.2 33 Q e - Engineering 6.5 3.4 2.8 9.5 <W n > [MW m -2 ] 2.8 3.0 3.4 4.2 P electric [MW] 1000 1000 1000 1000 1 J.E. Menard et al. Prospects for pilot plants based on the tokamak, spherical tokamak and stellarator. Nucl. Fusion 51(2011). • FLiBe was chosen as the liquid blanket material due to its favorable moderation capabilities and sufficient tritium breeding characteristics. • A dual-chambered, pressurized FLiBe blanket system enables a single working fluid design with reasonable tritium breeding ratio (TBR) of 1.125. • Minor radial cooling pipes connect the pressurized outer blanket to first wall cooling system. • The minor radial cooling pipes deliver cool FLiBe to toroidally running pipes to remove the first wall heat load, and then exhausts to the inner, hot blanket. • The FLiBe blanket system couples to a supercritical carbon dioxide Brayton cycle with a thermal efficiency of greater than 45%. • The primary cycle global temperature change is 100 o C. Immersive FLiBe blanket system allows for simple design and sufficient TBR of 1.125 Summary • A high-beta spheromak reactor system has been designed that achieves a sufficient TBR with an immersive, molten-salt blanket system. • Superconducting coil set and IDCD enable low recirculating power fraction. • Conventional nuclear materials and ITER developed technologies were implemented on the basis of technological feasibility. • Overnight capital cost of the dynomak reactor system is competitive with conventional power sources. • Future work includes: • Confirming plasma rotation and ensuring profile robustness in HIT-SI3. • Developing validated computer codes. • Demonstrating the compatibility between IDCD and confinement in a Proof of Principle (PoP) experiment. Dynomak reactor development path includes multiple upgrades and ITER data • The development path begins with a pulsed, Proof of Principle (PoP) experiment to demonstrate good confinement with IDCD. —> See Prof. Jarboe’s poster • Cost of fusion development is distributed among identically sized devices with various upgrades and additional components. • Total equipment cost for the development path is less than $1 billion. Plasma All HIT devices are R = 1.5 m, a = 1.0 m Add HTSC magnets, Steady-state operation, water cooling Add DT, FLiBe coolant, confirm TBR HIT-FNSF HIT-PX DT Plasma HIT-PoP Confinement development, copper coils, 10 second pulse Add SC-CO 2 secondary cycle, 20 MW electric HIT-PILOT/DEMO ITER β wall [%] Major Radius [m] Z [m]
