Recent construction milestones include setting the final of the "big six" structural modules for Unit 3 (CA-02 and CA-03, which form the walls of a storage tank that is part of the reactor's passive cooling system). The "big six" modules also include the previously installed CA-01, CA-04, and CA-05 in-containment structural modules, as well as the previously installed CA-20 structural module which forms part of the internal structure of the auxiliary building, containing many of the reactor's support systems. CA-02 and CA-03 were placed within the containment vessel in May 2016. The setting of these modules is a fairly significant milestone and allows other construction activities to commence. In June 2016, the final reactor coolant pump for Unit 3 was received on site. In November 2016, the reactor vessel for Unit 3 was set within the nuclear island. 2017 progress includes the installation of the reactor coolant loop piping and both steam generators at Unit 3. Progress has also been made in the turbine, auxiliary, and annex building. Unit 4 has also seen progress with the installation of the final two "big six" structural modules. Construction of both cooling towers is complete, with each nearly tall.