Economics of large superconducting toroidal magnets for fusion reactors

Technical Report · Tue Aug 01 04:00:00 EDT 1972

DOI:https://doi.org/10.2172/7355876· OSTI ID:7355876

Lubell, M. S.; Long, H. M.; Luton, J. N.; Stoddart, W. C.

The encouraging results over the last few years in plasma research have generated renewed optimism that fusion feasibility will be demonstrated in the coming decade. Assuming that such is the case, the next logical step is the construction of a prototype power reactor. If this reactor employs plasma containment by intense magnetic fields, it is highly likely that superconducting magnets will be required for economic reasons. We have previously performed a study on the engineering design of a large superconducting magnet system in a toroidal geometry. In this study, we considered a toroidal field B₀ = 37 kG, a maximum field at the windings B_max = 80 kG, a major radius of R = 10.5 m, and a minor coil radius r = 5.6 m, in a design using cryostatic stabilization of NbTi with copper. The design resulted in a magnet system with stored energy of 4 x 10¹⁰ J requiring 4.75 x 10⁸ ft of composite NbTi conductor. The total weight of the system including conductor, stainless steel interleaving, bobbin, bobbin reinforcement, and central compression ring was about 9,025 tons and the total cost was $70,500,000. The cost breakdown of the major components is: compound conductor, 37%; structural reinforcements, 32%; winding, 13%; bobbins, and refrigeration, 4%. A schematic view of a 5000 MW(th) tokamak fusion power reactor incorporating such a magnet system is shown. In this paper, work is extended and general formulas are developed for arbitrary B₀, R, and r, for each of the cost items considered in the study, and the total costs determined for a variety of fields and sizes. Although not as accurate as a detailed study, the general formula developed will be useful for quickly estimating the cost of any similar toroidal system subject to the constraint B_max ≤ 85 kG. The cost for any system is found to be proportional to the 4/5 power of the stored magnetic energy.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: US Atomic Energy Commission (AEC)
• DOE Contract Number: W-7405-ENG-26
• NSA Number: NSA-26-049613
• OSTI ID: 7355876
• Report Number(s): ORNL-TM--3927; CONF-720513--13; NSA-26-049613
• Country of Publication: United States
• Language: English

Related Subjects

420201 -- Engineering-- Cryogenic Equipment & Devices
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700202* -- Fusion Power Plant Technology-- Magnet Coils & Fields
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COST
ECONOMICS
ELECTRIC COILS
ELECTRICAL EQUIPMENT
ELECTROMAGNETS
EQUATIONS
EQUIPMENT
MAGNET COILS
MAGNETS
SUPERCONDUCTING DEVICES
SUPERCONDUCTING MAGNETS
THERMONUCLEAR REACTORS
TORI