Nuclear Reactor Physics - Nuclear Physics Basics

The aim of nuclear reactor physics is to quantify, using physico-mathematical methods and calculation software (or calculation codes) – neutron codes and radiation protection codes in particular – relevant macroscopic quantities enabling respectively :

• characterize the neutron state of a nuclear reactor core;

• assess the effect of radiation on organic and inert matter (materials) and take appropriate measures to protect against it.

In the field of nuclear reactors, neutrons and gamma rays are the two main types of radiation to be considered from different angles: propagation in matter, induced radioactive phenomena and particles emitted by interaction with matter. The energy range concerned typically extends from 0 to 20 MeV.

We begin by placing nuclear physics in the context of nuclear reactor physics. We then present the main definitions of the atomic nucleus and its fundamental properties. The final part of the article is devoted to the phenomena of radioactivity, describing some of its most important properties.

This document will be supplemented by articles [BN 3 011] and [BN 3 012] dealing respectively with nuclear reactions and the processing of nuclear data used by calculation codes dedicated to nuclear reactor physics.