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Title:
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Analysis of a thorium fuelled PWR
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Author(s):
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Published by:
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Publication date:
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ECN
NUCLEAIR
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1997
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ECN report number:
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Document type:
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ECN-R--97-013
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Other
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Number of pages:
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Full text:
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55
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Download PDF
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Abstract:
Burnup calculations have been performed on a PWR fuel lattice with threedifferent fuel types: ordinary UO2 fuel (LEU), 20W% enriched UO2 mixed in
ThO2 (MEU) and 93W% enriched UO2 mixed in ThO2 (HEU). Two burnup values of 60
and 100 GWd/tHM have been considered. Besides the nuclide densities and
radiotoxicity curves of the spent fuel, also the reactivity coefficients have
been calculated to assess the safety aspects of each fuel type. All fuel
types considered have acceptable values for the reactivity coefficients,
although the moderator temperature coefficient of the HEU fuel may become
positive due to the thermal spectrum and the corresponding high boron worth.
An accurate assessment of the critical boron concentration is needed in this
case. From the radiotoxicity point of view, the use of HEU fuel has
preference. Up to 20,000 years of storage, the radiotoxicity per unit
electricity generated is lower by a factor of five to ten compared to
ordinary LEU fuel. For the MEU fuel, this factor equals two. After this
period, the radiotoxicity curves of the MEU and HEU fuels increase due to
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