Explain how operators use in-core instrumentation to maintain reactor performance.

Operators use in-core instrumentation to maintain reactor performance by providing real-time data on the neutron flux distribution within the reactor core. This information allows them to monitor and adjust the reactor's operating parameters to achieve optimal power distribution, fuel efficiency, and safety margins. In-core instrumentation typically consists of neutron detectors strategically located throughout the core. These detectors measure the neutron flux at various locations, providing a three-dimensional map of the power distribution. Operators use this information to verify that the power distribution is within acceptable limits and to identify any areas of excessive power peaking. If the power distribution is not optimal, operators can adjust control rod positions or boron concentration in the coolant to redistribute the power and improve fuel utilization. In-core instrumentation also allows operators to monitor the fuel burnup distribution. As fuel burns up, its reactivity decreases, and the power distribution shifts. By monitoring the neutron flux distribution, operators can track the fuel burnup and make adjustments to maintain a uniform power distribution and maximize fuel life. In addition to power distribution and fuel burnup monitoring, in-core instrumentation can also be used to detect anomalies, such as fuel failures or control rod malfunctions. Any unusual changes in the neutron flux distribution can be an indication of a problem, allowing operators to take corrective actions before the problem escalates. The data from in-core instruments is processed by sophisticated computer systems that provide operators with clear and concise displays of the core's condition. These displays allow operators to quickly assess the reactor's performance and make informed decisions about how to maintain optimal operation.