Nuclear Energy by Zymal

What does Nuclear Fusion look like?

Hint: They bond together

Answer explanation

Here's the fusion reaction on the sun...

Temperatures and pressure bond the nuclei together.

What type of nuclear explosion was the Chornobyl Nuclear Plant Accident?

• Nuclear fission
• Nuclear meltdown
• Nuclear fusion
• Nuclear detonation

Where was the coolant water pumped from during the Fukushima Daiichi Nuclear Accident?

• The nearby ocean
• A nearby river
• A lake

• The emergency water reserve

Answer explanation

As the reactors 1, 2 and 3 were in a meltdown state, the coolant water was pumped from the nearby ocean.

Nuclear energy is generated through the process of _________, where the nucleus of an atom is split, releasing a large amount of energy.

What is the primary function of control rods in a nuclear reactor?

• To initiate nuclear fusion reactions

• To regulate the flow of coolant

• To absorb excess neutrons and control the rate of fission reactions

• To convert nuclear energy into electrical energy

Answer explanation

Control rods are an essential safety feature in nuclear reactors. They are typically made of materials like boron or cadmium that absorb neutrons. Neutrons are responsible for initiating and sustaining the nuclear fission chain reaction in the reactor core. By inserting or withdrawing control rods into the reactor core, operators can control the number of neutrons available to sustain the chain reaction. If the reactor becomes too hot or the chain reaction needs to be slowed down, control rods are inserted further into the core to absorb more neutrons, reducing the rate of fission reactions. Conversely, if more power is needed, control rods can be partially or fully withdrawn to allow more neutrons to initiate fission reactions, increasing the reactor's power output. This precise control over the neutron population helps maintain the reactor at a stable power level and ensures safe operation.

In a pressurized water reactor (PWR), what is mixed with water to serve as a neutron absorber and reactor coolant?

• Deuterium oxide (heavy water)

• Graphite

• Sodium

• Boric acid

Answer explanation

• Neutron Absorption: Boric acid acts as a neutron absorber, helping to control the rate of nuclear fission reactions in the reactor core. By absorbing neutrons, it helps regulate the nuclear chain reaction, preventing it from becoming too rapid and maintaining a stable reactor operation.

• Reactor Coolant: Water is the primary coolant in PWRs, circulating through the reactor core to remove heat generated by nuclear fission. Boric acid is dissolved in this coolant water to serve its dual purpose of neutron absorption and cooling. As the water circulates, it absorbs heat from the reactor core and transfers it to a secondary cooling system, which then produces steam to drive turbines and generate electricity.

Which of the following materials is commonly used as a moderator in nuclear reactors?

• Graphite
• Boron

• Lead

• Aluminum

Answer explanation

Graphite is used as a moderator in nuclear reactors to slow down fast neutrons, facilitating sustained fission reactions for energy production.

Which of the following is a characteristic of a boiling water reactor (BWR)?

• The reactor core is submerged in water

• Water acts as both a coolant and a moderator

• Steam is directly produced in the reactor core

• Control rods are used to regulate the flow of coolant

Answer explanation

In a boiling water reactor (BWR), steam is directly generated in the reactor core by boiling water, which is then used to drive turbines for electricity production.

Which of the following is a primary advantage of nuclear fusion over nuclear fission?

• Lower radioactive waste production

• Higher energy conversion efficiency

• Abundance of fuel supply

• Simpler reactor design

Answer explanation

Nuclear fusion's primary advantage over fission is its abundant fuel supply, mainly from isotopes of hydrogen, offering potential sustainability.

In a nuclear reactor, the term "criticality" refers to:

• The state where the reactor is completely shut down
• The state where the rate of nuclear reactions is constant and self-sustaining.
• The state where the rate of nuclear reactions is increasing exponentially
• The state where the reactor is producing electricity efficiently

Answer explanation

Criticality in a nuclear reactor means sustaining a stable nuclear chain reaction, vital for efficient energy production.