Patent ID: 8369474

Claim:
A nuclear fission reactor, comprising: a heat-generating nuclear fission fuel assembly configured to have at least a portion of a traveling burn wave; and a flow control assembly coupled to said nuclear fission fuel assembly and capable of modulating flow of a fluid stream in response to the traveling burn wave, the flow control assembly including: an outer sleeve defining therein a plurality of outer sleeve holes and having an outer sleeve engagement surface; an inner sleeve slidably insertable into the outer sleeve, the inner sleeve defining therein a plurality of inner sleeve holes that are progressively axially alignable with the plurality of outer sleeve holes; a carriage subassembly having a carriage subassembly engagement surface arranged to rotatably engage the outer sleeve engagement surface; and an anti-rotation mechanism that engages the outer sleeve and the inner sleeve, the anti-rotation mechanism restricting relative rotation of the outer sleeve with respect to the inner sleeve and permitting axial translation of the outer sleeve with respect to the inner sleeve.