To facilitate correctness and safety of mission-critical automation systems, formal methods should be applied in addition to simulation and testing. One of such formal methods is model checking, which is capable of verifying complex requirements for the system's model. If both the controller and the controlled plant are formally modeled, then the variant of this technique called closed-loop model checking can be applied. Recently, a technique of automatic plant model generation has been proposed which is applicable in this scenario. This paper continues the work in this direction by presenting two plant model construction approaches which are much more scalable with respect to the previous one, and puts this work into a more practical context. The approaches are evaluated on a case study from the nuclear automation domain