This is a source sought notice for design and construction services at the Nevada National Security Sites (NNSS), requiring travel to the location. The work involves comprehensive flush and test services for new cooling water systems and the end-to-end design, procurement, and fabrication of specific cooling system components. The selected subcontractor must also provide skilled support for installation and manage a qualified sub-tier vendor for the specialized flush and test services. The notice emphasizes the need for a subcontractor with a proven, system-wide understanding to manage this complex, integrated effort for a critical facility. No budget or specific performance timelines are detailed in this preliminary notice.