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Natural Gas Reforming to Industrial Gas and Chemicals Using Chemical Looping
Published in Subhas K Sikdar, Frank Princiotta, Advances in Carbon Management Technologies, 2020
Dawei Wang, Yitao Zhang, Fanhe Kong, L-S Fan, Andrew Tong
Process simulation on a CLR process with CO2 co-fed with natural gas, steam and recycled fuel gas from downstream processes to produce syngas for liquid fuels production, whose schematic diagram was shown in Figure 20, was conducted (Kathe et al., 2017). The CLR process used the moving bed CLR process with ITCMO particles, as described above. Like the beginning of section 2.2, the moving bed reducer of the CLR process was simulated using single stage RGibbs block from Aspen Plus®. The reducer was set to a temperature of 900 °C and a pressure of 1 atm. The equilibrium condition at the outlet of the reducer was simulated by the reducer model. The performance of the process was compared to the baseline case in section 2.1.3, which uses the conventional ATR for syngas production (Gollener et al., 2013).
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Published in Viorel Badescu, George Cristian Lazaroiu, Linda Barelli, POWER ENGINEERING Advances and Challenges, 2018
Recycle strategies are obviously more complex than once-through strategies, due to the undertaking of the additional steps of spent fuel reprocessing, fabrication of recycled fuel, and the need of irradiation facilities for transmutation of the recovered materials in recycled fuel. For example, the fabrication of recycled fuel containing one or more of the TRU elements is a complex task, requiring shielding and remote handling as determined by the activity of the TRU.4 Also, the irradiation of a fuel element containing a certain MA must be performed in such a way that its transmutation rate is greater than its production rate. As a general statement it can be said that effective reduction of fuel toxicity after irradiation can be accomplished with a closed fuel cycle with low enough reprocessing losses and high burn-up level (long fuel life). At present, the scientific feasibility of transmutation has been proven by the analysis of a few pins containing minor actinides, irradiated in various reactors (e.g., Phénix in France). But the capacity of a transmuting system to burn all the actinides it produces has not yet been proven, and it is one of the major goals of Gen IV R&D. Together with transmutation in a critical fast reactor, as envisaged in Fig. 2, the possibility to transmute in an accelerator-driven sub-critical fast system5 is presently studied, as well, due to several advantages of the latter, not least its higher safety in dealing with a core containing significant quantities of MAs.
Nuclear Fuel Recycling
Published in Kenneth D. Kok, Nuclear Engineering Handbook, 2016
Patricia Paviet, Michael F. Simpson
In the early era of nuclear power, many processes were investigated for the recovery of fissionable material from nuclear fuel. From 1956 to 1962, pyrochemical processes such as oxidative slagging, halide slagging, pyroredox, and electrorefining were investigated of recovery material from fast-breeder reactors (Moser and Navratil, 1983). Uranium was recovered from Experimental Breeder Reactor (EBR-II) fuel by melt refining (a type of pyroprocessing) from September 1954 to 1960. These operations processed approximately 5 MT (35,000 metal fuel pins) of spent fuel and included remote fuel fabrication with the recycled fuel being used in EBR-II reactor (Stevenson, 1987). The cessation of fuel processing and fabrication was not due to separations technology or equipment problems, but was simply a change in EBR-II mission to an irradiation facility for the national fast reactor development program.
Scoping Studies for a Lead-Lithium-Cooled, Minor-Actinide-Burning, Fission-Fusion Hybrid Reactor Design
Published in Nuclear Science and Engineering, 2023
Joshua Ruegsegger, Connor Moreno, Matthew Nyberg, Tim Bohm, Paul P. H. Wilson, Ben Lindley
There are many different fuel cycle schemes that can be used for the recycling of plutonium and MAs, either separately or together, with associated advantages and disadvantages.5 A subset of possible schemes partition uranium and plutonium (and possibly neptunium), from MAs and FPs, allowing separate recycling of plutonium and MAs. An advantage of this scheme is that U/Pu-based fuels are suitable for a wide range of reactor applications, including as mixed-oxide fuel in thermal reactors. A disadvantage is that MAs must then be handled separately in a specialist system, such as an externally driven system. This is mitigated by the relatively low proportion of recycled fuel that must be handled in this manner. The fission-fusion hybrid (FFH) is one such system. While FFHs have been investigated previously, their use with pure MA fuel (i.e., not containing other transuranics) is a relatively unexplored area.
A Preliminary Economic Assessment of Thorium-Based Fuels in a Pressure Tube Heavy Water Reactor
Published in Nuclear Technology, 2018
Alberto D. Mendoza España, Megan Moore, Ashlea V. Colton, Blair P. Bromley
Recently, the levelized fuel cycle cost for a once-through cycle in a PWR was estimated to be 5.94 ± 0.67 mills/kW·h and for a thermal reactor recycle [using reprocessing and fabrication of mixed oxide (MOX) fuel] was 6.13 ± 0.55 mills/kW·h (Ref. 38). Thus, the fuel cycle cost of the recycled fuel is approximately 3% larger, with a 9% uncertainty. The results38 suggest that two options (enriched uranium versus MOX) have comparable costs, with MOX being higher by 3% to 12%. The results may also imply that the cost estimates used in this study for reprocessing and recycling of Pu or 233U may be highly pessimistic or conservative. Thus, further investigation may be required to obtain more accurate and realistic estimates for the costs of reprocessing and recycling Pu and 233U. By comparison, the studies reported here give a value of $5.60/MW(electric)·h (or 5.6 mills/kW·h) for the front-end fuel cost for NU fuel, which is very comparable to that of the enriched fuel used in a PWR (Ref. 38).
Evaluation of Discharged Fuel in Preproposed Breed-and-Burn Reactors from Proliferation, Decay Heat, and Radiotoxicity Aspects
Published in Nuclear Science and Engineering, 2020
Kazuki Kuwagaki, Jun Nishiyama, Toru Obara
For a reference FBR core, the discharged fuel composition reported by Ahn17 was used. This reactor was composed of MOX recycled fuel (depleted uranium, minor actinide, and plutonium) and blanket fuels (depleted uranium). The total fuel mass was 29.1 tonne HM, and the core power was 3570 MW(thermal) throughout 510 days of operation. So the discharged burnup was 62.6 GWd/tonne HM. The sum of the two spent fuel compositions (MOX recycled fuel and blanket) was used as the reference FBR, which is shown with 19 actinides and 115 FPs in this reference. Although it is different from the chains of the SWR cores or of the PWR, this FBR’s discharged fuel was calculated just for the reference for the FBR, not for comparison.