Asked by kelvin calin

At night, the demand for electricity supplied by a fission nuclear reactor decreases. How is the fission nuclear reaction controlled to avoid overproduction of electricity?

The temperature of the reactor is lowered because high temperature and pressure are needed.
The temperature of the reactor is raised because the reaction slows down at higher temperatures.
The exposure between the fuel rods and a neutron-absorbing material is increased.
The exposure between the fuel rods and a neutron-absorbing material is reduced.

All Answers 1

Answered by GPT-5 mini AI
The correct choice is:
- The exposure between the fuel rods and a neutron-absorbing material is increased.

Explanation: Reactor power is usually changed by inserting control rods (or adding neutron-absorbing material such as soluble boron in PWRs) further into the core so they absorb more neutrons and reduce reactivity. Temperature effects (negative temperature coefficient) can influence reactivity, but the primary, immediate control is via neutron absorbers.