Overview

This training module is written as an introduction to reactor physics for reactor operators. It assumes the reader has a basic, fundamental knowledge of physics, materials and mathematics. The objective is to provide enough reactor theory knowledge to safely operate a typical research reactor. At this level, it does not necessarily provide enough information to evaluate the safety aspects of experiment or non-standard operation reviews.

The material provides a survey of basic reactor physics and kinetics of TRIGA type reactors. Subjects such as the multiplication factor, reactivity, temperature coefficients, poisoning, delayed neutrons and criticality are discussed in such a manner that even someone not familiar with reactor physics and kinetics can easily follow. A minimum of equations are used and several tables and graphs illustrate the text.

Individuals who desire a more detailed treatment of these topics are encouraged to obtain any of the available introductory textbooks or reactor theory and reactor physics.

Learning Objectives

  1. You should understand the neutron lifecycle, the infinite and effective multiplication factor and the concept of reactivity.
  2. You should understand the purpose of a neutron moderator and neutron reflector.
  3. You should be able to understand and explain the shape of the neutron flux within the reactor, how this is related to reactor power and how the movement of control rods and experiments will affect the flux shape and local reactor power.
  4. You should be able to understand and explain the affect of reactor “poisons” and how the concentration and affect of poisons produced from fission change with time.
  5. You should understand and be able to explain the concept of reactor period and how this concept is related to reactor reactivity using the in-hour formula.
  6. You should be able to define and explain subcritical multiplication, shutdown margin and core excess.
  7. You should be able to explain how a 1/M plot is used to determine criticality.