Summary

The purpose of this exercise is to study how transuranium nuclear waste is generated in a nuclear reactor. For this purpose a computer program will be written that simulates the nuclear reactions and disintegrations inside a nuclear-reactor core loaded with a specific fuel mixture. To keep the project manageable and relatively small we will introduce simplifications that make it possible to write the program and perform the simulations within a limited amount of time (about one day). Nevertheless the simulation will provide important understanding and insight into the dynamics of a running nuclear reactor. The main simplification used is that only thermal neutrons are present in our simulated reactor.

Follow this link for a general description of the concept of Computing in Science Education (CSE) exercises.

Learning Outcome

Performing this exercise should teach the student:

• A good understanding of the dynamics inside a reactor core (how the decay and in-growth of all the different nuclei is interlinked and depend on each other).
• A fundamental understanding of how the neutron flux will change the waste composition.
• A good understanding of how the waste composition changes as a function of time (both during irradiation and after).
• A good understanding of how the fuel composition will dictate the waste composition.
• Develop a more intimate feel for the basic workings of nuclear reactor.
• In addition, the student will learn how complex technology can be investigated by computer simulations.

Limitations

Many aspects of constructing and operating a nuclear reactor is not considered in this exercise. In particular, the importance of considering the effect neutron energy has on fission and n-capture cross-section is ignored. Furthermore, the effect of in-growth of neutron-absorbing nuclei ("poisons") is ignored. This exercise is not intended for - and will not convincingly model - the neutron inventory of a nuclear reactor. These limitations should be made clear for the students. This said, the simulation is quite useful in explaining and illustrating all the problems associated with nuclear waste.

Provided Material

Below you will find teaching material intended to be handed out to the students and guides for teachers on how to set up and execute the exercise. The student material can either be used as is or incorporated into your own learning material (e.g. a book of exercises or an student management platform). Feel free to use this material as you would like, provided it is for none-commercial purposes. If you develop the material further, we would much appreciate it if you could share the additional material here on NucWik. Likewise would we be very interested in your experience from using this exercise and material - please share!

Guides and Material for Students

• General introduction and student guide for this exercise. This is the hand-out for your students they should read as preparation for the exercise. In addition, you might want to point out relevant parts of your course book which they should read or already know before performing this exercise. It's written as a NucWik page and can be printed out directly or copied into your own delivery format.
• Extra help for the students: Depending on how much time you plan your students to spend on this exercise, you can provide some further help by providing them with a readymade input file (containing relevant nuclear data) and examples of how the data can be organized in the software. The best learning outcome is probably achieved if they figure out the data structure and assemble the data themselves, but it will probably take them many hours to do so. These tips were assembled by student Johannes Ø. Matsdal at UiO when he made a pilot for this exercise.
  • Here is an example of how the relevant parameters for the nuclei in the actinide region could be assembled: [ Excel file | Text file ]
  • Some programming tips, based on using the LabView language from National Instruments: [ Tips for using the input file | Tips for how to organize the data in LabView ]

Guides and Material for Teachers

• Teachers guide for this exercise
• General description of Computing in Science Education (CSE) exercises and how to use them in teaching (also linked at the top of this page).
• Ready to go programs and source code for performing this exercise:
  • LabView program written by Johannes Ø. Matsdal at UiO: [ Software Code ] [ Executable ] [ Explanations ]. Notice that you either need the LabView plug-in (2014 SP1 version) or LabView system installed to run the program, it is explained in the "Explanations" link.
• Examples of Obtained Results, from Johannes Ø. Matsdal (who wrote the pilot program to test out the concept)
• Compilation of experiences and advice from teachers and students. Here we assemble feed-back from teachers and students that have performed the exercise. Please help us to make this a long and useful list!

Development History and Contact Person

This exercise was conceived by Jon Petter Omtvedt (UiO) as part of the CINCH project. The initial development was made by Hans V. Lerum (UiO) and Omtvedt in 2014/2015. Pilot programs were written by Johannes Ø. Matsdal and Håkon Becstrøm during the summer of 2015, they also added many refinements and added ideas.

If you have comments, suggestions, examples of programs (in any language) or anything else relevant, please write in the comment page (use the NucWik page commenting tool, but you must be a registered user) or send your feed-back to NucWik-post@kjemi.uio.no. The teaching material for this particular CSE exercise is managed and updated by: Jon Petter Omtvedt. Feel free to contact me directly if you want to discuss this exercise or need help implementing it.