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Modelling spent fuel and HLW behaviour in repository conditions

Abstract

The aim of this report is to give the reader an overall insight of the different models, which are used to predict the long-term behaviour of the spent fuels and HLW disposed in a repository. The models must be established on basic data and robust kinetics describing the mechanisms controlling spent fuel alteration/dissolution in a repository. The UO2 matrix, or source term, contains embedded in it the , majority of radionuclides of the spent fuel (some are in the gap cladding). For this reason the SF radionuclides release models play a significant role in the performance assessment of radioactive waste disposal. The differences existing between models published in the literature are due to the conceptual understanding of the processes and the degree of the conservatism used with the parameter values, and the boundary conditions. They mainly differ in their level of simplification and their final objective. Sometimes are focused the show compliance with regulatory requirements, other to support decision making, to increase the level of confidence of public and scientific community, could be empirical, semi-empirical or analytical. The models take into account the experimental results from radionuclides releases and their extrapolation to the very long term. Its necessary a great  More>>
Publication Date:
Jul 01, 2003
Product Type:
Miscellaneous
Resource Relation:
Other Information: PBD: 2003; Related Information: In: Workshop on Modelling the Behaviour of Spent Fuel under repository conditions. june 5th to 7th, 2002. Palacio de los Velada, Avila, Spain, 175 pages.
Subject:
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS; SPENT FUELS; HIGH-LEVEL RADIOACTIVE WASTES; RADIOACTIVE WASTE STORAGE; KINETICS; RADIONUCLIDE MIGRATION; SOURCE TERMS
OSTI ID:
20360183
Country of Origin:
Spain
Language:
English
Other Identifying Numbers:
Other: ISBN 84-7834-440-3; TRN: ES03B0212
Submitting Site:
SPN
Size:
page(s) 13
Announcement Date:

Citation Formats

Esparza, A M, and Esteban, J A. Modelling spent fuel and HLW behaviour in repository conditions. Spain: N. p., 2003. Web.
Esparza, A M, & Esteban, J A. Modelling spent fuel and HLW behaviour in repository conditions. Spain.
Esparza, A M, and Esteban, J A. 2003. "Modelling spent fuel and HLW behaviour in repository conditions." Spain.
@misc{etde_20360183,
title = {Modelling spent fuel and HLW behaviour in repository conditions}
author = {Esparza, A M, and Esteban, J A}
abstractNote = {The aim of this report is to give the reader an overall insight of the different models, which are used to predict the long-term behaviour of the spent fuels and HLW disposed in a repository. The models must be established on basic data and robust kinetics describing the mechanisms controlling spent fuel alteration/dissolution in a repository. The UO2 matrix, or source term, contains embedded in it the , majority of radionuclides of the spent fuel (some are in the gap cladding). For this reason the SF radionuclides release models play a significant role in the performance assessment of radioactive waste disposal. The differences existing between models published in the literature are due to the conceptual understanding of the processes and the degree of the conservatism used with the parameter values, and the boundary conditions. They mainly differ in their level of simplification and their final objective. Sometimes are focused the show compliance with regulatory requirements, other to support decision making, to increase the level of confidence of public and scientific community, could be empirical, semi-empirical or analytical. The models take into account the experimental results from radionuclides releases and their extrapolation to the very long term. Its necessary a great statistics for have a representative dissolution rate, due at the number of experimental results is not very high and many of them show a great scatter, independently of theirs different compositions by axial and radial variations, due to linear power or local burnup. On the other hand, it is difficult to predict the spent fuel behaviour over the long term, based in short term experiments. In this report is given a little description of the radionuclides distribution in the spent fuel and also in the cladding/pellet gap, grain boundary, cracks and rim zones (the matrix rim zone can be considered with an especial characteristics very different to the rest of the spent fuel), and structural components such as Zircaloy, Inconel and stainless steel, to further on describing the radionuclides release from these zones. (Author)}
place = {Spain}
year = {2003}
month = {Jul}
}