Nuclear heat energy

Abstract

This chapter discusses the principal modes by which fission energy is transferred to a cooling agent and transported to devices that convert mechanical energy into electrical energy. Most of the energy released in fission appears as kinetic energy of high-speed particles. As these particles pass through matter, they are slowed down by multiple collisions and thus impart thermal energy to the medium. The radial temperature distribution in a fuel pellet is approximately parabolic. The rate of heat transfer from fuel surface to coolant by convection is directly proportional to the temperature difference. The coolant flows along channels and extracts the thermal energy for delivering it to an external circuit consisting of a heat exchanger (PWR), a steam turbine that drives an electrical generator, a steam condenser, and various pumps. Large amounts of waste heat are discharged by electrical power plants because of inherent limits on efficiency. Typically, a billion gallons of water per day must flow through the steam condenser to limit the temperature rise of the environment.