Isotope separation methods for self-consistent nuclear energy system

Ezoubtchenko, A N; Akatsuka, Hiroshi; Suzuki, Masao

doi:10.1016/s0149-1970(97)00086-3

Cited by 9 publications

(5 citation statements)

References 6 publications

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“…In this context, fast neutron spectrum reactor is the most attractive solution in the existing system with respect to the neutron balance, because of their high neutron flux and excess of neutrons 29 , 37 – 39 . Since most LLFPs have large neutron capture cross sections in the 1 to 10 3 eV region, the neutron spectrum must be softened to use the fast reactor system for transmuting LLFPs via resonance absorption.…”

Section: Introductionmentioning

confidence: 99%

Method to Reduce Long-lived Fission Products by Nuclear Transmutations with Fast Spectrum Reactors

Chiba

Wakabayashi

Tachi

et al. 2017

Sci Rep

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Transmutation of long-lived fission products (LLFPs: 79Se, 93Zr, 99Tc, 107Pd, 129I, and 135Cs) into short-lived or non-radioactive nuclides by fast neutron spectrum reactors without isotope separation has been proposed as a solution to the problem of radioactive wastes disposal. Despite investigation of many methods, such transmutation remains technologically difficult. To establish an effective and efficient transmutation system, we propose a novel neutron moderator material, yttrium deuteride (YD2), to soften the neutron spectrum leaking from the reactor core. Neutron energy spectra and effective half-lives of LLFPs, transmutation rates, and support ratios were evaluated with the continuous-energy Monte Carlo code MVP-II/MVP-BURN and the JENDL–4.0 cross section library. With the YD2 moderator in the radial blanket and shield regions, effective half-lives drastically decreased from 106 to 102 years and the support ratios reached 1.0 for all six LLFPs. This successful development and implementation of a transmutation system for LLFPs without isotope separation contributes to a the ability of fast spectrum reactors to reduce radioactive waste by consuming their own LLFPs.

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Section: Introductionmentioning

confidence: 99%

Method to Reduce Long-lived Fission Products by Nuclear Transmutations with Fast Spectrum Reactors

Chiba

Wakabayashi

Tachi

et al. 2017

Sci Rep

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“…It was known that its separation is not a formidable task even within the well-developed gas centrifuge method. 23,24) The isotope separation cost or political restrictions on the separation technology may be rather important to realize the transmutation. A transmutation of elemental Sn in the spallation target can be discussed as an alternative.…”

Section: Discussionmentioning

confidence: 99%

Transmutation of¹²⁶Sn in Spallation Targets of Accelerator-Driven Systems

Han

Saito

Sagara

2009

Journal of Nuclear Science and Technology

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The practical feasibility of 126 Sn transmutation in spallation targets of accelerator-driven systems was evaluated from the viewpoints of accumulation of radioactive spallation products and neutron production as well as transmutation amount of 126 Sn. A cylindrical liquid 126 Sn target whose length depends on proton beam energy was described, based on a Pb-Bi target design of accelerator-driven system being developed in JAEA. A proton beam of 1.5 GeV-20 mA was estimated to give the transmutation rate of 126 Sn 6.4 kg/ yr, which corresponds to the amount of 126 Sn annually discharged in 27 LWRs of 1 GWt and 33 GWd/ THM. The equilibrium radioactivity of spallation products would reach 9% of that of 126 Sn transmuted in the spallation target, and the equilibrium toxicity would be just 3%. Some parametric analyses showed that the effective half-life of 126 Sn could be reduced through a proper reduction of the target size. The 126 Sn target was calculated to produce 40 neutrons per proton of 1.5 GeV and give a neutron spectrum very similar to that of the reference Pb-Bi target. As a result, the transmutation of 126 Sn in the spallation target has a high feasibility in terms of better transmutation performance and comparable target performance.

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“…In consequence, cryogenic distillation, which is a well-established technique that has been used for many decades for isotope separation, also in ITER (together with the combined electrolysis and catalytic exchange process [24]), and could likely be adapted to DEMO did only reach a score here of 64% (it will be revisited for exhaust detritiation functions in the outer loop). Furthermore, some more exotic, potentially promising high-purity separation technologies were found (such as plasma separation [25], laser isotope separation [26] or cryogenic quantum sieving [27]), but they were considered to be a too high risk option since there does not appear to be sufficient literature to demonstrate that they work on hydrogen isotopes and in technical scale.…”

Section: Technology Review and Gap Analysismentioning

confidence: 99%

Consequences of the technology survey and gap analysis on the EU DEMO R&D programme in tritium, matter injection and vacuum

Day

Butler

Giegerich

et al. 2016

Fusion Engineering and Design

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In the framework of the EUROfusion Programme, EU is preparing the conceptual design of the inner fuel cycle of a pulsed tokamak DEMO. This paper illustrates a quantified process to shape a R&D programme that exploits as much as possible previous R&D. In an initial step, the high-level requirements are collected and a novel DEMO inner fuel cycle architecture with its three subsystems vacuum pumping, matter injection (fuelling and injection of plasma enhancement gases) and tritium systems (tritium plant and breeder coolant purification) is delineated, driven by the DEMO key challenge to reduce tritium inventory. Then, a technology survey is carried out to review potential existing solutions for the required process functions and to assess their maturity and risks. Finally, a decision-making scheme is applied to select the most promising candidates. ITER technology is exploited where possible. As a primary result, a fuel cycle architecture is suggested with an advanced tritium plant that avoids full isotope separation in the main loop and with a Direct Internal Recycling path in the vacuum systems to shorten cycle times. For core fuelling, classical inboard pellet injection technology is selected, in principle similar to that proposed for ITER but aiming for higher launch speeds to achieve deep fuelling of the DEMO plasma. Based on these findings, a tailored R&D programme is shaped that tackles the key questions until 2020.

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Isotope separation methods for self-consistent nuclear energy system

Cited by 9 publications

References 6 publications

Method to Reduce Long-lived Fission Products by Nuclear Transmutations with Fast Spectrum Reactors

Method to Reduce Long-lived Fission Products by Nuclear Transmutations with Fast Spectrum Reactors

Transmutation of¹²⁶Sn in Spallation Targets of Accelerator-Driven Systems

Consequences of the technology survey and gap analysis on the EU DEMO R&D programme in tritium, matter injection and vacuum

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Isotope separation methods for self-consistent nuclear energy system

Cited by 9 publications

References 6 publications

Method to Reduce Long-lived Fission Products by Nuclear Transmutations with Fast Spectrum Reactors

Method to Reduce Long-lived Fission Products by Nuclear Transmutations with Fast Spectrum Reactors

Transmutation of126Sn in Spallation Targets of Accelerator-Driven Systems

Consequences of the technology survey and gap analysis on the EU DEMO R&D programme in tritium, matter injection and vacuum

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Transmutation of¹²⁶Sn in Spallation Targets of Accelerator-Driven Systems