In this document it is proposed to describe the plant site and to outline the nature of the pile in order to show the specific design and layout requirements for the production of plutonium by nuclear synthesis. The selection of the plant site involved a number of special considerations. An essential requirement was a large dependable supply of relatively pure water that remains at a fairly low temperature throughout the year. A large source of power was required to circulate the tremendous quantities of water. The potential dangers connected with the high energies of the nuclear reaction and the formation of a large quantity of radioactive by- products required large distances between each operating section of the plant, and between the plant and main rail and highway routes. The plant site layout and reactor areas are discussed in the first part of the chapter, followed by a functional description of the more essential pile components. The chapter concludes with a discussion of reactor instrumentation. 24 figs., 2 tabs.