Purpose of experiment

A negative fuel temperature reactivity feedback effect is of key importance in inherently safe reactor design. The purpose of the experiment is to measure the fuel temperature reactivity coefficient of the TRIGA reactor, i.e. the reactivity change due to a change in the fuel temperature.

Outcome / What you will learn
Students will:

  1. discuss the physical principles governing fuel temperature reactivity feedback
  2. observe the response of the reactivity, fuel temperature and reactor power, in a sequence of swift changes in reactivity, caused by the movement of a control rod
  3. understand the feedback effect of the fuel temperature on the reactivity and the power of a reactor – this being a prerequisite for understanding the temperature and power reactivity defects.

After discussion on the physical principles governing the fuel temperature reactivity effects, students determine the fuel temperature coefficient of reactivity as a function of the fuel temperature, and the power coefficient of reactivity as a function of power.

Exercise No. 3: Fuel temperature coefficient of reactivity