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Smarter waste strategies: Helping deliver on the promise of advanced nuclear
At COP28, held in Dubai in 2023, a clear consensus emerged: Nuclear energy must be a cornerstone of the global clean energy transition. With electricity demand projected to soar as we decarbonize not just power but also industry, transport, and heat, the case for new nuclear is compelling. More than 20 countries committed to tripling global nuclear capacity by 2050. In the United States alone, the Department of Energy forecasts that the country’s current nuclear capacity could more than triple, adding 200 GW of new nuclear to the existing 95 GW by mid-century.
Yuichi Ogawa, Nobuyuki Inoue, Zensho Yoshida, Kunihiko Okano
Fusion Science and Technology | Volume 24 | Number 2 | September 1993 | Pages 188-199
Technical Paper | Plasma Engineering | doi.org/10.13182/FST93-A30225
Articles are hosted by Taylor and Francis Online.
The plasma and machine parameters of a pulsed tokamak reactor with a day-long operation period have been studied, where engineering constraints such as maximum toroidal field strength are preserved at International Thermonuclear Experimental Reactor (ITER) levels so as to realize a fusion reactor with only a short-range extension of currently available technology. To provide the magnetic flux necessary to sustain a plasma current inductively for 1 day or longer, plasmas with a major radius of R > 9.5 m are necessary, and a plasma with an aspect ratio as high as A > 5 should be employed. Typical parameters are as follows: major radius R = 10 m, minor radius a = 1.85 m, plasma elongation κ = 1.8, plasma current Ip = 12.2MA, toroidal field on axis Bt >= 7.56 T, and safety factor at the plasma surface qψ = 3. A plasma volume V ∼ 1200 m3 is comparable with that of ITER, even though the major radius of a day-long operation reactor is relatively large. A very small amount of heating power (∼ 15 MW) with a heating time of only a few tens of seconds is sufficient to achieve the ignition condition. This is well within the capacity of auxiliary heating systems currently used in large tokamak devices. A confinement improvement factor (from L mode) of fL > 1.7 is required to design a reactor with a reasonable machine size and a day-long pulse duration. The operation temperature is chosen to be 〈T〉 = 20 keV with a toroidal beta βt = 2.6% (Troyon factor g = 3), which gives a fusion power Pfus = 2.5 GW even for an alpha-particle dilution nα/ne of 10%. The bootstrap current fraction is 50% or more of the total current, and current profile needed for the beta limit could be achieved with a combination ofohmic current in the plasma center region and bootstrap current in the outer region. If the maximum toroidal field is set much higher, as in proposed recent reactor designs for the Steady-State Tokamak Reactor (SSTR) and ARIES, a more attractive plasma with a larger safety factor can be designed, and the pulse length can be extended remarkably.
