This textbook covers the core subjects of nuclear engineering. Developed to meet the needs of today's students and nuclear power plant operators, the text establishes a framework for the various areas of knowledge that comprise the field and explains rather than just defines the relevant physical phenomena. For today's engineer the principal analytical design tool is the personal computer. The text takes advantage of this recent development. PC programs are provided which either expand the computational range accessible to the student, or serve to illustrate the relevant physical phenomena. Some of the included programs are simplified versions of computational procedures used in the field and can be used as training tool for design calculations. The text devotes special attention to subjects which have an impact on the safe operation of nuclear power reactors. This includes the design of safety optimized core configurations, the physical mechanisms underlying the various reactivity coefficients, and the calibration procedures for control rods. A final chapter is devoted to the licensing and safety evaluation of power reactors.