I work on an electron ranch herding electrons in circles, and periodically driving them through a magnetic chicane to induce them to spawn x-ray photons for use in scientific experiments.
.........
Wouldn’t you also be herding electrons if you herded the electrons from nuclear reactor electron scatter into a current?...
(I don’t understand the processes well enough to offer anything more than analogies.)
The problem is the “scatter” part; all those electrons are going in different directions, and the energy required to steer them all into a single unidirectional stream would not be offset by the energy of that stream.
The entire exercise would be a net consumer of power, not a net producer.
Keep thinking outside the box, though; genius can spring up just about anywhere.