Why modern nuclear knowledge would still need industrial support

Could a Victorian engineer build a steampunk nuclear reactor with modern knowledge?

Suitable control systems would be difficult to supply, and the imagined period improvisation is treated as unsafe.

Knowledge of uranium would leave a Victorian inventor short of the instrumentation and control capability needed to operate a stable reactor. A period improvisation is imagined as possible, but with serious reservations about working near it. The surrounding industrial and control systems remain part of the technological problem.