Study on reactivity control strategies for the thermoelectric integrated space nuclear reactor

摘要

The Autonomous Circulation Miniature Integrated nuclear Reactor (ACMIR) has features of compact structure, high power density and high efficiency. The reactivity control strategy is an important aspect in the design of ACMIR, which is essential for reactor safe operation. In this paper, two ex-core reactivity control options, namely, the rotating control drums and sliding reflector segments, were investigated. Furthermore, an optimization design was conducted on both strategies, including alternative absorber materials, thickness of absorber, absorber angle and the thickness of reflector. Finally, we analyzed and compared the neutronic characteristics with different control schemes, including the reactivity insertion behavior, reactivity temperature coefficient, submersion criticality and spatial power distribution. This work helps to improve the safety characteristics of ACMIR in reactivity control and operation. (C) 2020 Elsevier Ltd. All rights reserved.