This branch of nuclear engineering is very specific and dependent on a reactor type. This article focuses on the most common types of reactors – Pressurized Water Reactors. PWRs have much in common with Boiling Water Reactors, but the operation of the reactors is not the same. On the other hand, for example, fast neutron reactors have completely different physics than PWRs and BWRs.
Reactor operation physics is very important for each nuclear power plant since it determines how a reactor responds during all modes of operation. Basic reactor operation physics includes these topics:
- Reactor Startup (“criticality approach”)
- Control of the Reactor and Power Maneuvering.
- Axial Offset Control
- Xenon Oscillations
- Fuel Burnup
- Reactor Shutdown
- Emergency Shutdown – SCRAM
Special measures must be taken during the startup of a reactor to ensure that expected responses are occurring. During the criticality approach, the subcritical multiplication determines the response of a reactor, while during power operation, the reactor dynamics are completely different. Power operation is primarily about fuel burnup and control of the flux shape, which is necessary to ensure operation within limits and maximum core performance. Even when a reactor is shut down, the fact that the fission products created by the fission process continue to generate heat results in need to monitor support systems to ensure adequate core cooling.
This chapter is also concerned with medium- and long-term kinetics, where:
- Medium-term kinetics describes phenomena that occur for several hours to a few days. This comprises especially effects of neutron poisons on the reactivity (i.e., Xenon poisoning or spatial oscillations).
- Long-term kinetics describes phenomena that occur over months or even years. This comprises all long-term changes in fuel composition due to fuel burnup.