Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 21: Problem 40

Explain the functions of a moderator and a control rod in a nuclear reactor.

Short Answer

Expert verified
In a nuclear reactor, a moderator slows down the fast neutrons produced by nuclear fission, making it possible for more nuclear fissions to occur. Control rods, on the other hand, absorb neutrons to control the rate of nuclear fission, thereby regulating the amount of energy produced.

Step by step solution

01

Function of a Moderator

The moderator is responsible for slowing down the fast neutrons produced by nuclear fission. Doing this increases the possibility of more nuclear fissions occurring since slow neutrons are more likely to cause fission. Common moderators include light water, heavy water, or graphite.
02

Function of Control Rods

Control rods are used to control the fission rate of uranium and plutonium. They perform this function by absorbing the neutrons that are released during nuclear fission. By adjusting the height of the control rods inside the nuclear reactor, we can control the number of neutrons that participate in the chain reaction; therefore, the amount of energy produced can be regulated. Control rods are usually made of materials like boron, silver, indium and cadmium that are good neutron absorbers.
03

Balancing the Role of Moderator and Control Rods

Together, the moderator and control rods regulate the nuclear fission process inside a nuclear reactor. The moderator slows down the neutrons to make them suitable for causing additional fissions, while the control rods can absorb neutrons to decrease the fission rate when required. The balance between these two functions helps maintaining the chain reaction at a steady level, thus ensuring the controlled production of heat.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Define nuclear binding energy, mass defect, and nucleon.

The radius of a uranium- 235 nucleus is about \(7.0 \times\) \(10^{-3} \mathrm{pm} .\) Calculate the density of the nucleus in \(\mathrm{g} / \mathrm{cm}^{3}\). (Assume the atomic mass is 235 amu.)

What are the advantages of a fusion reactor over a fission reactor? What are the practical difficulties in operating a large-scale fusion reactor?

Discuss the differences between a light water and a heavy water nuclear fission reactor. What are the advantages of a breeder reactor over a conventional nuclear fission reactor?

As a result of being exposed to the radiation released during the Chernobyl nuclear accident, the dose of iodine- 131 in a person's body is \(7.4 \mathrm{mC}(1 \mathrm{mC}=1 \times\) \(10^{-3} \mathrm{Ci}\) ). Use the relationship rate \(=\lambda N\) to calculate the number of atoms of iodine- 131 to which this radioactivity corresponds. (The half-life of \({ }^{131} \mathrm{I}\) is 8.1 days.)
See all solutions

Recommended explanations on Chemistry Textbooks

Nuclear Chemistry

Read Explanation

Organic Chemistry

Read Explanation

Physical Chemistry

Read Explanation

Chemical Analysis

Read Explanation

Inorganic Chemistry

Read Explanation

Making Measurements

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free