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Nuclear power plants in the United States are increasingly challenged to compete in wholesale electricity markets due to the low electricity costs and increasingly dynamic grid conditions from competing generation sources. An alternative market for nuclear power is industrial facilities that can use the thermal and/or electrical power generated by a nuclear power plant to offset the economic losses incurred by electricity market challenges. A generic pressurized water reactor (PWR) simulator was used to show the results of a basic design for a generic thermal power extraction system and tests were run using a set of procedures to show what happens when a nuclear power plant transitions from full electrical power dispatch to 15% and 50% thermal power dispatch. This type of operation leads to losses in turbine performance efficiency due to the deviation from the design operating point, but because the thermal power is also used by the industry load without conversion losses, the combined thermal efficiency of the PWR increases. For the 15% case, the thermal efficiency increased from 32% to 41.9%, while for the 50% case, the efficiency increased up to 60.1%. In addition, for 50% thermal power dispatch, the power dissipated by the condenser decreased from approximately 2000 to approximately 1300 MW (thermal), indicating a substantially diminished impact on the environment in terms of releasing heat into the cooling water reservoir. [ABSTRACT FROM AUTHOR]

Nuclear energy technology has to evolve continuously toward two goals: reduction of the cost of power plants and increasing their safety margins. One approach that can enhance both the economics and safety performance is the adoption of new fuel geometries that increase the fuel surface-to-volume ratio in the core. This will facilitate heat transfer to coolant at lower fuel temperatures. This paper reviews the methodology applied to develop an appropriate design of an innovative internally and externally cooled annular fuel for high-powerdensity pressurized water reactors (PWRs). It provides an overview of key results obtained during a U.S. Department of Energy-sponsored project that addressed thermal hydraulics, reactor physics, fuel manufacturing, and fuel performance characterization. Using this fuel, it is shown that power density uprates up to 150% can be achieved in PWRs while maintaining or improving the safety margins. If this is applied to future reactors, significant economic advantages can be realized. Even when the power level is maintained close to what it is in existing power reactors, the annular fuel will greatly enhance safety and facilitate higher burnup of the fuel. [ABSTRACT FROM AUTHOR]