  The shadow limit is a versatile tool used to study the reduction of
reaction-diffusion systems into simpler PDE-ODE models by letting one of the
diffusion coefficients tend to infinity. This reduction has been used to
understand different qualitative properties and their interplay between the
original model and its reduced version. The aim of this work is to extend
previous results about the controllability of linear reaction-diffusion
equations and how this property is inherited by the corresponding shadow model.
Defining a suitable class of nonlinearities and improving some uniform Carleman
estimates, we extend the results to the semilinear case and prove that the
original model is null-controllable and that the shadow limit preserves this
important feature.
