Prospects for Disruption Handling in a Tokamak-Based Fusion Reactor

Abstract

Disruptions present a great challenge to achieving an economically viable commercial tokamak fusion reactor. Disruption handling, including prevention, mitigation, and resilient design, must be incorporated into future reactor designs at the same priority as core performance and steady-state heat flux removal. Prevention requires avoiding unstable regimes; actively stabilizing instabilities if they do appear; or, if those steps should fail, terminating the plasma-controlled rampdown. Mitigation is a last resort that utilizes massive impurity injection to reduce a damaging concentration of thermal and mechanical loads. Extremely robust disruption prevention will be of paramount importance to ensure high duty factor and capital return on the reactor investment, but the reactor environment poses significant technical challenges exceeding those in ITER. The long-term mission of a commercial reactor motivates investment in passive resilient design to survive disruptions in the absence of active intervention.