Simulation of 15% and 50% Thermal Power Dispatch to an Industrial Facility Using a Flexible Generic Full-Scope Pressurized Water Reactor Plant Simulator

Stephen Hancock,Tyler Westover

doi:10.3390/en15031151

Abstract

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.

Highlights

Nuclear power plants (NPPs) in the United States are increasingly challenged to compete with natural gas combined cycle plants in wholesale electricity markets [1]
The flows in the systems in that procedure are small and pose much lower risk to the plant in terms of causing any type of disruption or safety event, and so they are not discussed here. The results of this process are presented in a series of transient plots for several important parameters of NPP operation
These are intended to show that the reactor power was maintained at or slightly below 100% thermal power during the entire transient and that all important systems were maintained at their full power levels. This simulation started by establishing steady state at hot standby, continued with the transition from full electrical power generation to steady-state, mixed-mode operation, and it ended with the transition back to steady-state full electrical power generation

Summary

Introduction

Nuclear power plants (NPPs) in the United States are increasingly challenged to compete with natural gas combined cycle plants in wholesale electricity markets [1]. When intermittent renewable generation, such as wind and solar, are added to the equation, the minute-by-minute marginal cost of electricity can drop below zero because large-scale producers cannot decrease generation These extreme prices force NPPs to operate at a loss during portions of the year. There are at least two key benefits for this type of coupling with nuclear reactors It allows a portion of the thermal power from the reactor to be used as heat without the losses inherent in the turbine generator system and, second, the thermal and electric power can be dynamically shared between multiple users to keep the total thermal power generated by the reactor effectively constant for maximum efficiency and minimum cost per unit of dispatched energy [2]. Each application requires a unique design and operating system because the amount of thermal and/or electrical power demand for the process plant varies for each process

Methods

Results

Conclusion