Comparison of uranium- and thorium-based plutonium-recycling in a pressurized water reactor
Comparison of uranium- and thorium-based plutonium-recycling in a pressurized water reactor
The accumulation of civil Plutonium from nuclear energy production continuously attains attention as a world wide safety concern. A reliable elimination of the civil Plutonium as well as that from dismantling of nuclear war heads rnay be achieved only by its fission ; intermediate storage or deep un...
Saved in:
Personal Name(s): | Neuhaus, I. |
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Phlippen, P.-W. | |
Contributing Institute: |
Publikationen vor 2000; PRE-2000; Retrocat |
Imprint: |
Jülich
Forschungszentrum Jülich, Zentralbibliothek, Verlag
1999
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Physical Description: |
XII, 57 p. |
Document Type: |
Report Book |
Research Program: |
Addenda |
Series Title: |
Berichte des Forschungszentrums Jülich
3690 |
Link: |
OpenAccess OpenAccess |
Publikationsportal JuSER |
The accumulation of civil Plutonium from nuclear energy production continuously attains attention as a world wide safety concern. A reliable elimination of the civil Plutonium as well as that from dismantling of nuclear war heads rnay be achieved only by its fission ; intermediate storage or deep underground disposal whatever technical line is followed - allows only a temporary limited "elimination" of that weapons grade material. Plutonium can be fissioned either in today's nuclear reactors or with future reactors or accelerator driven systems being constructed especially for this tack. The application of Thorium based nuclear fuels, containing Plutonium as a fissile material, allows a very efficient consumption of Plutonium as the breeding chain of Thorium produces no Plutonium. $^{233}$U is breed instead, which in some ways is classified less dangerous than Plutonium. This paper reports the results of a comparison of Thorium based fuels in pressurised water reactors with Uranium based mixed oxide fuels up to burn-ups of100 GWd/t$_{HM}$. First, consumption ratios for Plutonium and Transuranium elements are compared. lt turned out that the application of Thorium based fuel doubles the consumption ratio of Plutonium in comparison to Uranium mixed oxide fuel. This also becomes evident evaluating the mass balances with respect to the generated nuclear energy. Also in this rase the Thorium based fuel demonstrates its superior performance; it generates rnore than 90 % of the energy due to Plutonium fissioning, thus performing approximately 40 % better than Uranium based mixed oxide fuel. But the large amounts of Transuranium elements remaining in both types of fuel are disadvantageous; thus these fuels may not be seen as a solution of the Plutonium problem for the purposes of avoiding large Plutonium amounts to be disposed off. Besides the valuation of consumption ratios the Feed back due to the change of fuel raust be evaluated with respect to the safety behaviour of the reactor. Basing on the reactivity feedback coefficients of the fuel temperature, the moderator temperature, the boron concentration and the voided core, it can be shown, that Thorium based mixed oxide fuel performs better than Uranium based mixed oxide fuel. But both types of fuel run into trouble, if very high burn-ups are desired. Due to high initial Plutonium concentrations the void coefficient tends to become positive. A final judgement of this result needs a more detailed core layout analysis. With respect to final disposal both the reprocessing residuals from the UO$_{2}$-fuel and the spent mixed oxide fuels do not perform significantly different. On the one hand rnore than 40 % of the initial Plutonium remains in the spent mixed oxide fuel, on the other hand no Minor Actinides are separated from UO$_{2}$ fuel, which contribute to 10 % to the mass of Transuranium elements. That's why the toxicity potential may not change significantly with respect to spent UO$_{2}$ fuel. As the long [...] |