scholarly journals Evaluating Reactivity Control Options for a Chloride Salt-Based Molten Salt Zero-Power Reactor

2021 ◽  
Vol 11 (16) ◽  
pp. 7447
Author(s):  
Bruno Merk ◽  
Anna Detkina ◽  
Seddon Atkinson ◽  
Dzianis Litskevich ◽  
Gregory Cartland-Glover
Keyword(s):  
Molten Salt ◽  
Fuel Cycle ◽  
Power Reactor ◽  
Singular System ◽  
System Level ◽  
Chloride Salt ◽  
Solid Core ◽  
Closed Fuel Cycle ◽  
The Core ◽  
Reactor Experiment

Molten salt reactors have gained substantial interest in recent years due to their flexibility and their potential for simplified closed fuel cycle operation for massive net-zero energy production. However, a zero-power reactor experiment will be an essential first step in the process of delivering this technology. The topic of the control and shutdown for a zero-power reactor is, for the first time, introduced through a literature review and a reduction in the control approaches to a limited number of basic functions with different variations. In the following, the requirements for the control and shutdown systems for a reactor experiment are formulated, and based on these assessments, an approach for the shutdown, i.e., splitting the lower part of the core with a reflector, and an approach for the control, i.e., a vertically movable radial reflector, are proposed. Both systems will be usable for a zero-power system with a liquid as well as a solid core, and even more importantly, both systems somehow work at the integral system level without disturbing the central part of the core which will be the essential area for the experimental measurements. Both approaches were investigated as a singular system, in addition to their interactions with one another and the sensitivity of the control system. This study demonstrates that both proposed systems are able to deliver the required characteristics with a sufficient shutdown margin and a sufficiently wide control span. The interaction of the system is shown to be manageable, and the sensitivity is at a very good level. The multi-group Monte Carlo approach was cross-evaluated by a continuous energy test, leading to good results, but they also demonstrate that there is room for improvement.

scholarly journals Innovative Investigation of Reflector Options for the Control of a Chloride-Based Molten Salt Zero-Power Reactor

2021 ◽  
Vol 11 (15) ◽  
pp. 6795
Author(s):  
Bruno Merk ◽  
Anna Detkina ◽  
Seddon Atkinson ◽  
Dzianis Litskevich ◽  
Gregory Cartland-Glover
Keyword(s):  
Monte Carlo ◽  
Molten Salt ◽  
Power Distribution ◽  
Fuel Cycle ◽  
Power Reactor ◽  
Cost Savings ◽  
Monte Carlo Study ◽  
Beryllium Oxide ◽  
Negative Effects ◽  
Closed Fuel Cycle

Molten salt reactors have gained substantial interest in the last years due to their flexibility and their potential for simplified closed fuel cycle operations for massive net-zero energy production. However, a zero-power reactor experiment will be an essential first step into the process delivering this technology. The choice of the optimal reflector material is one of the key issues for such experiments since, on the one hand, it offers huge cost savings potential due to reduced fuel demand; on the other hand, an improper choice of the reflector material can have negative effects on the quality of the experiments. The choice of the reflector material is, for the first time, introduced through a literature review and a discussion of potential roles of the reflector. The 2D study of different potential reflector materials has delivered a first down-selection with SS304 as the representative for stainless steel, lead, copper, graphite, and beryllium oxide. A deeper look identified, in addition, iron-based material with a high Si content. The following evaluation of the power distribution has shown the strong influence of the moderating reflectors, creating a massively disturbed power distribution with a peak at the core boundary. This effect has been confirmed through a deeper analysis of the 2D multi-group flux distribution, which led to the exclusion of the BeO and the graphite reflector. The most promising materials identified were SS304, lead, and copper. The final 3D Monte Carlo study demonstrated that all three materials have the potential to reduce the required amount of fuel by up to 60% compared with NaCl, which has been used in previous studies and is now taken as the reference. An initial cost analysis has identified the SS304 reflector as the most attractive solution. The results of the 2D multi-group deterministic study and the 3D multi-group Monte Carlo study have been confirmed through a continuous energy Monte Carlo reference calculation, showing only minor differences.

scholarly journals On the Dimensions Required for a Molten Salt Zero Power Reactor Operating on Chloride Salts

2021 ◽  
Vol 11 (15) ◽  
pp. 6673
Author(s):  
Bruno Merk ◽  
Anna Detkina ◽  
Seddon Atkinson ◽  
Dzianis Litskevich ◽  
Gregory Cartland-Glover
Keyword(s):  
Heavy Metal ◽  
Molten Salt ◽  
Spent Nuclear Fuel ◽  
Fuel Cycle ◽  
Power Reactor ◽  
Modelling And Simulation ◽  
Advanced Technology ◽  
Electricity Production ◽  
Eutectic System ◽  
Low Carbon

Molten salt reactors have gained substantial interest in the last years due to their flexibility and their potential for simplified closed fuel cycle operation for massive expansion in low-carbon electricity production, which will be required for a future net-zero society. The importance of a zero-power reactor for the process of developing a new, innovative rector concept, such as that required for the molten salt fast reactor based on iMAGINE technology, which operates directly on spent nuclear fuel, is described here. It is based on historical developments as well as the current demand for experimental results and key factors that are relevant to the success of the next step in the development process of all innovative reactor types. In the systematic modelling and simulation of a zero-power molten salt reactor, the radius and the feedback effects are studied for a eutectic based system, while a heavy metal rich chloride-based system are studied depending on the uranium enrichment accompanied with the effects on neutron flux spectrum and spatial distribution. These results are used to support the relevant decision for the narrowing down of the configurations supported by considerations on cost and proliferation for the follow up 3-D analysis. The results provide for the first time a systematic modelling and simulation approach for a new reactor physics experiment for an advanced technology. The expected core volumes for these configurations have been studied using multi-group and continuous energy Monte-Carlo simulations identifying the 35% enriched systems as the most attractive. This finally leads to the choice of heavy metal rich compositions with 35% enrichment as the reference system for future studies of the next steps in the zero power reactor investigation. An alternative could be the eutectic system in the case the increased core diameter is manageable. The inter-comparison of the different applied codes and approaches available in the SCALE package has delivered a very good agreement between the results, creating trust into the developed and used models and methods.

TRU Recycling Options for Environmentally Friendly and Proliferation-Resistant Nuclear Fuel Cycle of FBR

2010 ◽  
Author(s):  
Sidik Permana ◽  
Mitsutoshi Suzuki
Keyword(s):  
High Performance ◽  
Fuel Cycle ◽  
Operation Time ◽  
Nuclear Nonproliferation ◽  
High Level Waste ◽  
Minor Actinide ◽  
Spent Fuel ◽  
Closed Fuel Cycle ◽  
The Core ◽  
High Level

The embodied challenges for introducing closed fuel cycle are utilizing advanced fuel reprocessing and fabrication facilities as well as nuclear nonproliferation aspect. Optimization target of advanced reactor design should be maintained properly to obtain high performance of safety, fuel breeding and reducing some long-lived and high level radioactivity of spent fuel by closed fuel cycle options. In this paper, the contribution of loading trans-uranium to the core performance, fuel production, and reduction of minor actinide in high level waste (HLW) have been investigated during reactor operation of large fast breeder reactor (FBR). Excess reactivity can be reduced by loading some minor actinide in the core which affect to the increase of fuel breeding capability, however, some small reduction values of breeding capability are obtained when minor actinides are loaded in the blanket regions. As a total composition, MA compositions are reduced by increasing operation time. Relatively smaller reduction value was obtained at end of operation by blanket regions (9%) than core regions (15%). In addition, adopting closed cycle of MA obtains better intrinsic aspect of nuclear nonproliferation based on the increase of even mass plutonium in the isotopic plutonium composition.

Prospects of subcritical molten salt reactor for minor actinides incineration in closed fuel cycle

Kerntechnik ◽  
2015 ◽  
Vol 80 (4) ◽  
pp. 389-393 ◽  
Author(s):  
P. N. Alekseev ◽  
A. L. Balanin ◽  
V. Yu. Blandinsky ◽  
A. A. Dudnikov ◽  
P. A. Fomichenko ◽  
...  
Keyword(s):  
Molten Salt ◽  
Fuel Cycle ◽  
Minor Actinides ◽  
Molten Salt Reactor ◽  
Closed Fuel Cycle

scholarly journals FUEL TAP: A SIMPLIFIED BREED AND BURN MSR

2021 ◽  
Vol 247 ◽  
pp. 01007
Author(s):  
Rodrigo G.G. de Oliveira ◽  
Boris A. Hombourger
Keyword(s):  
Preliminary Analysis ◽  
Fuel Cycle ◽  
Chloride Salt ◽  
Core Size ◽  
Fuel Utilization ◽  
The Core ◽  
Start Up ◽  
Breed And Burn ◽  
Fluid Design ◽  
Core Simulation

Breed-and-burn Molten Salt Reactors are an interesting option of reactor design that allow high fuel utilization while operating on an open fuel cycle. Such reactors usually require specialized codes in order to model its fuel cycle and the flowing fuel in an unmoderated core. In this work, we propose a design and perform a preliminary analysis of a homogeneous chloride salt single-fluid design. The fuel cycle is analyzed using the EQL0D tool in order to model reactor start-up and transition into an equilibrium state. Core simulation is performed using ATARI, an OpenFOAM-based multiphysics code developed at PSI. Results show that the core size for such a reactor is quite big and that it can be easily started with high-assay LEU. In addition, the core has been designed to promote a quasi-1D flow, opening the possibility of modeling the core with legacy codes in the future.

scholarly journals An optimization methodology for heterogeneous minor actinides transmutation

2018 ◽  
Vol 4 ◽  
pp. 4
Author(s):  
Timothée Kooyman ◽  
Laurent Buiron ◽  
Gérald Rimpault
Keyword(s):  
Fuel Cycle ◽  
Volume Fraction ◽  
Negative Impact ◽  
Positive Impact ◽  
Optimal Solution ◽  
Minor Actinides ◽  
Spent Fuel ◽  
Closed Fuel Cycle ◽  
Decay Heat ◽  
The Core

In the case of a closed fuel cycle, minor actinides transmutation can lead to a strong reduction in spent fuel radiotoxicity and decay heat. In the heterogeneous approach, minor actinides are loaded in dedicated targets located at the core periphery so that long-lived minor actinides undergo fission and are turned in shorter-lived fission products. However, such targets require a specific design process due to high helium production in the fuel, high flux gradient at the core periphery and low power production. Additionally, the targets are generally manufactured with a high content in minor actinides in order to compensate for the low flux level at the core periphery. This leads to negative impacts on the fuel cycle in terms of neutron source and decay heat of the irradiated targets, which penalize their handling and reprocessing. In this paper, a simplified methodology for the design of targets is coupled with a method for the optimization of transmutation which takes into account both transmutation performances and fuel cycle impacts. The uncertainties and performances of this methodology are evaluated and shown to be sufficient to carry out scoping studies. An illustration is then made by considering the use of moderating material in the targets, which has a positive impact on the minor actinides consumption but a negative impact both on fuel cycle constraints (higher decay heat and neutron) and on assembly design (higher helium production and lower fuel volume fraction). It is shown that the use of moderating material is an optimal solution of the transmutation problem with regards to consumption and fuel cycle impacts, even when taking geometrical design considerations into account.

scholarly journals Neutronic benchmark of the molten salt fast reactor in the frame of the EVOL and MARS collaborative projects

2019 ◽  
Vol 5 ◽  
pp. 2 ◽  
Author(s):  
Mariya Brovchenko ◽  
Jan-Leen Kloosterman ◽  
Lelio Luzzi ◽  
Elsa Merle ◽  
Daniel Heuer ◽  
...  
Keyword(s):  
Molten Salt ◽  
Fast Reactor ◽  
Fuel Cycle ◽  
Negative Temperature ◽  
Nuclear Data ◽  
Data Set ◽  
The Core ◽  
Waste Production ◽  
Reactivity Coefficients ◽  
Core Characteristics

This paper describes the neutronic benchmarks and the results obtained by the various participants of the FP7 project EVOL and the ROSATOM project MARS. The aim of the benchmarks was two-fold: first to verify and validate each of the code packages of the project partners, adapted for liquid-fueled reactors, and second to check the dependence of the core characteristics to nuclear data set for application on a molten salt fast reactor (MSFR). The MSFR operates with the thorium fuel cycle and can be started with 233U-enriched U and/or TRU elements as initial fissile load. All three compositions were covered by the present benchmark. The calculations have confirmed that the MSFR has very favorable characteristics not present in other Gen4 fast reactors, like strong negative temperature and void reactivity coefficients, a low-fissile inventory, a reduced long-lived waste production and its burning capacities of nuclear waste produced in currently operational reactors.

scholarly journals Preliminary proliferation study of the molten salt fast reactor

2020 ◽  
Vol 6 ◽  
pp. 5 ◽  
Author(s):  
Michel Allibert ◽  
Elsa Merle ◽  
Sylvie Delpech ◽  
Delphine Gerardin ◽  
Daniel Heuer ◽  
...  
Keyword(s):  
Molten Salt ◽  
Fast Reactor ◽  
Molten Salts ◽  
Fuel Cycle ◽  
Power Reactor ◽  
Nuclear Material ◽  
Reactor System ◽  
Molten Salt Reactor ◽  
International Forum ◽  
Large Power

The molten salt reactor designs, where fissile and fertile materials are dissolved in molten salts, under consideration in the framework of the Generation IV International Forum, present some unusual characteristics in terms of design, operation, safety and also proliferation resistance issues. This paper has the main objective of presenting some proliferation challenges for the reference version of the Molten Salt Fast Reactor (MSFR), a large power reactor based on the thorium fuel cycle. Preliminary studies of proliferation resistance are presented here, dedicated to the threat of nuclear material diversion in the MSFR, considering both the reactor system itself and the processing units located onsite.

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