This paper summarizes a series of conceptual design studies conducted with the purpose of determining if tokamak fusion neutron sources based on ITER physics and technology could meet the neutron source requirements for sub-critical fast-spectrum nuclear reactors that would help to close the nuclear fuel cycle by transmuting the transuranics in spent nuclear fuel. The studies were constrained to nuclear reactor and materials technologies under consideration in the US nuclear programme. Fuel cycle studies indicate that fusion neutron sources in the range ∼200–500 MW would meet the needs of transmutation reactors, depending on other constraints such as materials damage to the nuclear fuel. A tokamak with R = 3.75 m, a = 1.1 m, B = 5.7–5.9 T, q95 = 3.00–4.0, I = 8.3–10 MA, βN = 2.0–2.85, HIPB98 = 1.0–1.06, γcd = 0.6 A Wm−2 would meet these requirements.
Feasibility study of tokamak, helical and laser reactors as affordable fusion volumetric neutron sources