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Transmutation of All German Transuranium under Nuclear Phase Out Conditions - Is This Feasible from Neutronic Point of View?

Merk B, Litskevich D - PLoS ONE (2015)

Bottom Line: A basic insight for the optimization of the time duration of the deep burn phase is given.Further on, a detailed balance of different isotopic inventories is given to allow a deeper understanding of the processes during transmutation in the molten salt fast reactor.The effect of modeling and simulation is investigated based on three different modeling strategies and two different code versions.

View Article: PubMed Central - PubMed

Affiliation: Institute of Resource Ecology, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany.

ABSTRACT
The German government has decided for the nuclear phase out, but a decision on a strategy for the management of the highly radioactive waste is not defined yet. Partitioning and Transmutation (P&T) could be considered as a technological option for the management of highly radioactive waste, therefore a wide study has been conducted. In the study group objectives for P&T and the boundary conditions of the phase out have been discussed. The fulfillment of the given objectives is analyzed from neutronics point of view using simulations of a molten salt reactor with fast neutron spectrum. It is shown that the efficient transmutation of all existing transuranium isotopes would be possible from neutronic point of view in a time frame of about 60 years. For this task three reactors of a mostly new technology would have to be developed and a twofold life cycle consisting of a transmuter operation and a deep burn phase would be required. A basic insight for the optimization of the time duration of the deep burn phase is given. Further on, a detailed balance of different isotopic inventories is given to allow a deeper understanding of the processes during transmutation in the molten salt fast reactor. The effect of modeling and simulation is investigated based on three different modeling strategies and two different code versions.

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(Right): Simplified scheme of the MSFR system including the core, blanket and heat exchangers (IHX)–(Left): Benchmark definition [30].
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pone.0145652.g002: (Right): Simplified scheme of the MSFR system including the core, blanket and heat exchangers (IHX)–(Left): Benchmark definition [30].

Mentions: The calculations are based on the core dimensions and the boundary conditions given in the EVOL benchmark definition (see Fig 2). The reference is a MSFR with 3000 MWth and a fast neutron spectrum. In a first approach, which has been refined during the project, the core is a single cylinder. The nuclear reactions occur within the flowing fuel salt inside the cylinder [29]. The dimensions are shown in Fig 2. The core is composed of four volumes: the active core, the upper extraction area, the lower injection area, and the out of core area with the heat exchanger and the pumps. The used TRU isotopic vector (see Table 1) follows the definition of the EVOL benchmark. It is given by the configuration to be expected after a single use of UOX in a PWR to a final burnup of 60 GWd/tHM after five years of storage [29]. The TRU isotopic vector is one generic configuration. In the case of a real transmutation, the TRU isotopic vector would vary since the TRUs will not be pooled after reprocessing due to criticality reasons. Additionally, the TRU vector undergoes some changes due to the decay of some TRU isotopes, mostly Pu-241 and Cm-244. Generally, the TRU isotopic vector depends:


Transmutation of All German Transuranium under Nuclear Phase Out Conditions - Is This Feasible from Neutronic Point of View?

Merk B, Litskevich D - PLoS ONE (2015)

(Right): Simplified scheme of the MSFR system including the core, blanket and heat exchangers (IHX)–(Left): Benchmark definition [30].
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4696651&req=5

pone.0145652.g002: (Right): Simplified scheme of the MSFR system including the core, blanket and heat exchangers (IHX)–(Left): Benchmark definition [30].
Mentions: The calculations are based on the core dimensions and the boundary conditions given in the EVOL benchmark definition (see Fig 2). The reference is a MSFR with 3000 MWth and a fast neutron spectrum. In a first approach, which has been refined during the project, the core is a single cylinder. The nuclear reactions occur within the flowing fuel salt inside the cylinder [29]. The dimensions are shown in Fig 2. The core is composed of four volumes: the active core, the upper extraction area, the lower injection area, and the out of core area with the heat exchanger and the pumps. The used TRU isotopic vector (see Table 1) follows the definition of the EVOL benchmark. It is given by the configuration to be expected after a single use of UOX in a PWR to a final burnup of 60 GWd/tHM after five years of storage [29]. The TRU isotopic vector is one generic configuration. In the case of a real transmutation, the TRU isotopic vector would vary since the TRUs will not be pooled after reprocessing due to criticality reasons. Additionally, the TRU vector undergoes some changes due to the decay of some TRU isotopes, mostly Pu-241 and Cm-244. Generally, the TRU isotopic vector depends:

Bottom Line: A basic insight for the optimization of the time duration of the deep burn phase is given.Further on, a detailed balance of different isotopic inventories is given to allow a deeper understanding of the processes during transmutation in the molten salt fast reactor.The effect of modeling and simulation is investigated based on three different modeling strategies and two different code versions.

View Article: PubMed Central - PubMed

Affiliation: Institute of Resource Ecology, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany.

ABSTRACT
The German government has decided for the nuclear phase out, but a decision on a strategy for the management of the highly radioactive waste is not defined yet. Partitioning and Transmutation (P&T) could be considered as a technological option for the management of highly radioactive waste, therefore a wide study has been conducted. In the study group objectives for P&T and the boundary conditions of the phase out have been discussed. The fulfillment of the given objectives is analyzed from neutronics point of view using simulations of a molten salt reactor with fast neutron spectrum. It is shown that the efficient transmutation of all existing transuranium isotopes would be possible from neutronic point of view in a time frame of about 60 years. For this task three reactors of a mostly new technology would have to be developed and a twofold life cycle consisting of a transmuter operation and a deep burn phase would be required. A basic insight for the optimization of the time duration of the deep burn phase is given. Further on, a detailed balance of different isotopic inventories is given to allow a deeper understanding of the processes during transmutation in the molten salt fast reactor. The effect of modeling and simulation is investigated based on three different modeling strategies and two different code versions.

Show MeSH
Related in: MedlinePlus