Abstract
To ensure a safe and reliable handling and storage of Spent Nuclear Fuel (SNF), properties such as decay heat, neutron emission, gamma emission and reactivity are important.
Determining these properties by absolute measurements is too complex. Therefore, they are derived from theoretical model calculations of the isotopic composition using fuel depletion codes.
In this thesis, the impact of different modelling and operational parameters on the isotopic composition of the SNF is analysed using the Monte Carlo fuel depletion codes ALEPH version 2.9.0 and Serpent version 2.1.32. Using data available in offcial reports, the SFCOMPO-2.0 database and the Rod Extremities and Gadolinia AnaLysis (REGAL) project offcial documentation, an accurate model is constructed for diffrent cases and the predicted isotopic compositions are compared to experimental results.
First, an existing model of Gosgen-1 sample GU1 has been improved. Next, the Takahama-3 SF96 sample 1 has been modelled and a comparison between a 2D and 3D model has been made. In the 2D model, the sensitivity to the moderator density and the number of burnable poison rods has been investigated. A good agreement between the experimental and calculated results for the 2D simulations using ALEPH2 in these two cases is found.
Lastly, sensitivity analyses of the Tihange-1 sample D05 are carried out using Serpent 2. The four most important parameters calculated are the pellet diameter, the fuel density, fuel enrichment and the moderator temperature.
Determining these properties by absolute measurements is too complex. Therefore, they are derived from theoretical model calculations of the isotopic composition using fuel depletion codes.
In this thesis, the impact of different modelling and operational parameters on the isotopic composition of the SNF is analysed using the Monte Carlo fuel depletion codes ALEPH version 2.9.0 and Serpent version 2.1.32. Using data available in offcial reports, the SFCOMPO-2.0 database and the Rod Extremities and Gadolinia AnaLysis (REGAL) project offcial documentation, an accurate model is constructed for diffrent cases and the predicted isotopic compositions are compared to experimental results.
First, an existing model of Gosgen-1 sample GU1 has been improved. Next, the Takahama-3 SF96 sample 1 has been modelled and a comparison between a 2D and 3D model has been made. In the 2D model, the sensitivity to the moderator density and the number of burnable poison rods has been investigated. A good agreement between the experimental and calculated results for the 2D simulations using ALEPH2 in these two cases is found.
Lastly, sensitivity analyses of the Tihange-1 sample D05 are carried out using Serpent 2. The four most important parameters calculated are the pellet diameter, the fuel density, fuel enrichment and the moderator temperature.
Original language | English |
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Qualification | Master of Science |
Awarding Institution |
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Supervisors/Advisors |
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Date of Award | 6 Jun 2022 |
State | Published - Jun 2022 |