Module 2. Presentation
Back-end of the nuclear fuel cycle
The nuclear fuel cycle is the set of processes to condition fertile and fissile materials to produce energy in a nuclear reactor and subsequently reprocess and recycle, or store them,
safely safeguarding the resulting radioactive waste.
The fuel cycle begins with the extraction of uranium ore, going through its milling, concentration, conversion, enrichment, fuel irradiation in the reactor, and the steps associated with the selected spent fuel disposal strategy.
The nuclear fuel cycle can be divided into two categories, the open cycle, and the closed cycle; the main difference being that the irradiated fuel is not reprocessed and recycled in the open cycle. As can be seen in Figure 1, in the open cycle, the fuel once it leaves the nuclear reactor is temporarily stored, either in spent fuel pools and/or in containers or in concrete vaults; these last two known as dry storage methods. Subsequently, the spent fuel is properly conditioned and definitively disposed of in a permanent repository, such as a Deep Geological Storage.
In the case of the closed cycle, the fuel is reprocessed and recycled, recovering part of the uranium still available in the fuel, as well as the plutonium that was produced in the reactor.
As can be seen in the figure, the spent fuel, after temporary storage, goes through a reprocessing process to separate the uranium and plutonium, and reuse them to produce new fuels.
The steps that take place after the fuel has produced energy in the reactor are known as the back-end of the nuclear fuel cycle which is the subject of this module.
Figure 1. Nuclear fuel cycle.
Fuente: World Nuclear Association Image Library (https://www.world-nuclear.org/gallery/the-world-nuclear-fuel-report-expanded-summary/the-nuclear-fuel-cycle.aspx)
Objectives
At the end of this module, the student will be able to:
- List the different stages of the back-end.
- Describe the basic characteristics of each stage of the back-end.
- Identify the facilities associated with each stage of the back-end worldwide.
- Estimate the composition, heat of decay and radiotoxicity of spent fuel.
Module evaluation form
The student will solve a questionnaire by topic and apply a case study.
