After World War II, electric power consumption in the United States increased at a rate of approximately 7% per year. To meet this demand, the Tennessee Valley Authority (TVA) launched an ambitious program of constructing 17 large nuclear power stations, beginning with the Browns Ferry Nuclear Plant in 1966. The portion of the nuclear plants outside of the nuclear steam supply, referred to herein as the "balance of plant" (BOP) was designed by the TVA Division of Engineering Design (DED) in Knoxville, Tennessee.Rampant inflation approaching 15% annuall during the Carter administration, forced the cost of electric power to soar, and the demand for electric power dropped precipitously. At the same time, the disastrous accident at the Three Mile Island Nuclear Generating Station in 1979 turned public opinion against nuclear power. TVA decided not to complete most of the nuclear plants that were under construction. However somewhat belatedly, a consensus may now be forming that nuclear power may be the only hope for society to achieve success against global warming, since it does not produce carbon dioxide. Realizing that at some point in the future nuclear power might becomes a feasible option again, TVA authorized the highly competent engineers in the DED to produce design guides documenting best engineering practices in designing the BOP of both boiling water and pressurized water reactor nuclear power plants for the benefit of future generations. These design guides reflect the practices employed in the design of the later plants that corrected the many flaws that experience revealed in the earlier designs. These design guides, largely unused for over 40 years, contain a vast amount of useful information. The author was privileged to work alongside the engineers who prepared these design guides for the mechanical discipline and herewith publishes them for the use of posterity. The design guides contained in this book are exact copies of those prepared, reviewed, and approved by TVA over 40 years ago. Quite obviously, some references to equipment manufacturers and codes and/or industry standards may be out of date. The information is made available to the general public at a nominal cost, and neither the publisher nor TVA assume any responsibility for the accuracy of the information contained herein.