Small Modular Nuclear Reactors

Reducing greenhouse gas emissions and improving energy production sustainability is a paramount of Chile's 2050 energy policy. This though, is difficult to achieve without some degree of nuclear power involvement, given that the geography of the country consists of many areas that are practically off-grid, whereas cannot be developed and financially exploited due to the lack of basic commodities such as water and electricity. Recently small modular reactors (SMRs) have gained lots of attention by both researchers and world policy makers for their promised capabilities of enhanced safety systems, affordable costs and competitive scalability. SMRs can be located in remote areas and at this time are being actively developed in South Africa. Chile's 2010 earthquake and Fukushima's 2011 nuclear disaster have increased significantly both the population's fear and opposition to Nuclear Power Energy for the possible consequences of radiation on the lives of people. This paper aims to study the seismic resistance of a typical nuclear structure, being at time proposed in Small Modular Reactors, by using earthquake conditions typically seen in Chile. Since many designs are under study, a NuScale reactor from USA is analyzed under these extreme loading conditions. The major advantages of the NuScale reactor are in the power scalability (it can go from 1 to 12 reactor cores producing from 60 to 720 MWe), limited nuclear fuel concentration, modules allocated below grade and high strength steel containments fully immersed in water. The cooling effect beyond Design Basis Accident is ensured indefinitely, which induces a significant safety factor in the case of an accident. For the purpose of this study a detailed 3D detailed structural model was developed, reproducing the NuScale reactor's reinforced concrete framing system, where nonlinear analyses was performed to assess the overall mechanical response of the structure. The framing system has been tested under high seismic excitations typically seen in Chile (Mw > 8.0), showing high resistance and capability to cope with the developed forces due to its design. Based on a Soil-Structure Interaction analysis, it was also found that the NuScale framing system manages to maintain a low-stress level at the interaction surface between the foundation and the soil, where the structural system was found to be able to withstand significant earthquake loads. Finally, further investigation is deemed necessary in order to study the potential damages of the structure in the case of other hazards such as tsunami events, blast loads, etc.

Nuclear energy currently accounts for a declining share of global electricity, but it is possible that rising concerns about global climate change and China's ambitious nuclear program could reverse this trend. This review attempts to assess the global future of nuclear power, showing how the optimistic forecasts in the early days of nuclear power have been replaced by far more modest forecasts. The review first discusses the controversies surrounding nuclear power. It then briefly examines the prospects for three proposed reactors of the future: Small Modular Reactors; Generation IV breeder reactors; fusion reactors. It finally discusses the social and political context for nuclear power, both today and in the future.

Nuclear power still plays an important role for reducing CO 2 emission. At the same time, small scale and small capacity reactors, such called " small modular reactor (SM R) " is the recent trend of developing as new generation. On the other hand, molten salt reactor (M SR) is remarked as safe, high economy way as nuclear power. There are numbers of new proposals of M SR both for large and small capacity reactor in these just a few years. The author's proposal named " UNOM I (Universally operable molten salt reactor integrated) " is also among such small capacity M SR. In this paper, these new designs of M SR are reviewed from a view of engineering feasibility.

11 Sodium-cooled fast reactor (SFR) is considered the most promising of the Generation IV 12 reactors for their near-term demonstration of power generation. Small modular SFRs (SM-13 SFRs) have less investment risk, can be deployed more quickly, are easier to operate and are 14 more flexible in comparison to large nuclear reactor. Currently, SFRs use the proven Rankine 15 steam cycle as the power conversion system. However, a key challenge is to prevent dangerous 16 sodium-water reaction that could happen in SFR coupled to steam cycle. Nitrogen gas is inert 17 and does not react with sodium. Hence, intercooled closed Brayton cycle (CBC) using nitrogen 18 as working fluid and with a single shaft configuration has been one common power conversion 19 system option for possible near-term demonstration of SFR. In this work, a new two shaft 20 nitrogen CBC with parallel turbines was proposed as a way to further simplify the design of 21 the turbomachinery and reduce turbomachinery size without compromising the cycle 22 efficiency (or even a possible improvement in efficiency). Furthermore, thermodynamic 23 performance analysis and preliminary design of components were carried out in comparison 24 with a reference single shaft nitrogen cycle. Mathematical models in Matlab were developed 25 for steady state thermodynamic analysis of the cycles and for preliminary design of the heat 26 exchangers, turbines and compressors. Studies were performed to investigate the impact of the 27 recuperator minimum terminal temperature difference (TTD) on the overall cycle efficiency 28 and recuperator size. The effect of turbomachinery efficiencies on the overall cycle efficiency 29 was examined. The results showed that the cycle efficiency of the proposed configuration was 30 comparable to the 39.44% efficiency of the reference cycle. In addition, the study indicated 31 that the new configuration has the potential to simplify the design of turbomachinery, reduce 32 the size of turbomachinery and provide opportunity for improving the efficiency of the 33 turbomachinery. The findings so far revealed that the proposed two-shaft CBC with nitrogen 34 as working fluid could be a promising power conversion system for SM-SFRs near-term 35 demonstration. 36 37 Keywords 38 Sodium-cooled fast reactor 39

As energy needs grow worldwide, huge technological advancements have been made in all the fields to meet the demand – from conventional energy sources of fossil fuels, hydel power or conventional nuclear to newer sources like renewables backed by advanced battery storage. On the nuclear power frontier, very small and small modular reactors (vSMRs and SMRs) are the latest technological marvels to join the energy generation bandwagon. The International Atomic Energy Agency (IAEA) defines 'small' as under 300 MWe and very small reactors – vSMRs as under about 15 MWe.  As of 2020, there are several vSMRs and SMRs, that are in various stages of evolution i.e. concept-formulation, design and development for civilian applications. Several hundred examples however exist for their naval use. These reactors are proposed for use in remote locations where electrical grid power is not available, e.g. in mining operations, oil and gas rigs, chemical plants, military installations, isolated/secluded communities, etc. Because of their modular design and small footprint, they are easily transportable. Modules can be installed & commissioned, successfully operated and de-commissioned, once their working cycle has ended. They have substantially longer fuel replenishment cycles, allowing for the fuel rods or the reactor itself to be replaced, once it reaches the end of its life cycle.  These can work in tandem with existing power facilities to provide these remote locations with power on a near perpetual basis. With years of relevant research and receiving that right impetus and support from international government authorities, micro-SMRs are one step closer than ever to becoming a reality.

Nuclear technology is one of the main base-load electricity-generating sources available in the world today. Nuclear energy generated 11.2% of the global power production in 2013. According to the International Atomic Energy Agency (IAEA), the use of nuclear energy for the generation of electricity is expected to grow around the world, particularly in some specific regions, as demand for electricity increases as foreseen.

This is a 2019-2024 strategic plan for a town with a population of 1,000 located near Wawa, Ontario, Canada, on . Challenges include quality of digital connections, retaining young people, attracting workers, and managing the potential influx of additional residents given the potential opening of a second gold mine. Eco-tourism and other types of year-round activities are part of the potential of the area.

Last year was undoubtedly the year of the small modular reactor (SMR)-the amount of hot air and hype spouted about the "most influential and innovative energy disruptors the world has ever seen" could power the world indefinitely. This double-issue of Nuclear Monitor focuses exclusively on SMRs. We hope it will be a useful resource and we will of course continue to follow the debates-please subscribe at https://wiseinternational.org/nuclear-monitor
Small modular reactors: an introduction and an obituary The forgotten history of small nuclear reactors
SMR economics: an overview
No-one wants to pay for SMRs: US and UK case studies
Are thousands of new nuclear generators in Canada's future?
Small modular reactors and nuclear weapons proliferation
A military bromance: SMRs to support and cross-subsidize the UK nuclear weapons program
SMRs to power military installations and forward bases in the United States
SMR safety issues
Generation IV nuclear waste claims debunked
mPower: an obituary
High-temperature, gas-cooled zombie SMRs
SMR fantasies: a pictorial essay

In the advancing world of today, the demand for clean and reliable electricity is constantly increasing. With restrains on carbon emissions and with the reduction of fossil fuel
reserves; the need of the hour is efficient nuclear power plants.  With this paper, it is demonstrated that with modular helium cooled reactors using spherical fuel elements; it is possible to increase the efficiency of the reactor cycle with a safer nuclear process control. In addition, it is also demonstrated that parallel to electricity production, conversion of methane to hydrogen will be carried out simultaneously, thus decreasing the operational cost of such a nuclear power plant

This research paper explores the history and the development of small modular nuclear reactors (SMRs), discusses their technological features and examines the potential future military utility of SMRs through a number of analytical lenses.

The work describes two proposals for hydrogen production using the HTR-PM reactor as an energy source. Both proposals take advantage of the high output temperatures of the 2 × 250 MWth HTR-PM project to increase the efficiency of hydrogen production processes. Two proposals are analysed, the hydrogen production through the Cu-Cl cycle and the high temperature electrolysis process. To evaluate the efficiency of the proposed conceptual designs, two computational models were developed in a chemical process simulator. A determination of the efficiency of the hydrogen production process coupled to the HTR-PM was carried out using the computational model developed. The high temperature electrolysis (HTE) process can produce 0.7821 kg/s of hydrogen with 27.37% of efficiency. The Cu-Cl process, although producing less hydrogen, 0.5637 kg/s, has higher overall efficiency (32.12%) than the HTE, mainly due to less global exergy destruction and higher exergetic efficiency.

Even after the huge impact of Fukushima Daiichi nuclear power plant accident, Japan has to establish its energy supply system satisfying requirements of both global warming and resistibility of natural disaster. Nuclear power has a potential to reduce carbon emission but large-scale and centralized nuclear power plant may lose large volume of electricity supply at once. Small-scale nuclear power plants will bring solution in Japan. Thorium molten-salt reactor (MSR) is selected to simulate implementation capacity of small reactors in Japan. In order to use thorium as nuclear fuel, fissionable isotope is indispensable since natural thorium does not include fissile material. Japan owns plutonium in spent nuclear fuel of uranium usage. Quantitative evaluation of implementing capacity of thorium MSR in Japan by using plutonium accumulated in Japan. Implementation capacity of thorium MSR will be about 38 GWe and 11.2 GWe in the maximum and minimum cases at 2050, respectively.

Undoubtedly, interest in SMRs continues to grow as a real option for future power generation and energy security, particularly in developing countries. However, the first
phase of advanced SMRs deployment will have to ultimately demonstrate high levels of
plant safety and reliability, and prove their economics in order for further commercialization to be feasible. It is important to highlight that this type of nuclear power reactor would have greater automation but will still rely on human interaction for supervision, system management, and operational decisions because operators are still regarded as the last line of defense if failures in automated protective measures occur.

CO2ZERO – Zero Emissions Reforming Operation
1. Circular economies as a pathway to sustainability
      A. What would a global industrial system without waste look like?
            i. Major Contributors
            ii. Electrification
            iii. Renewables
            iv. Nuclear
            v. Gasification
            vi. Economics
            vii. Scalability
            viii. Waste
      B. Associated risks and opportunities
            i. Carbon Capture
            ii. Forests
            iii. Biofuels
            iv. Modular Reactors
            v. Renewable Storage
            vi. Natural Resources
2. Integrated systems for enabling scalable circular economies
      A. Bulk material separation – an integrated system
            i. Carbochlorination – TRL 9
            ii. Gaseous Chloride Hydrolysis – TRL 9
            iii. Chloride Neutralization – TRL 9
            iv. Steam Methane Reaction – TRL 9
            v. Volatile Partitioning – TRL 9
            vi. Molten Partitioning – TRL 9
            vii. Chemical Vapor Transport – TRL 4
            viii. Molten Salt Electrolysis – TRL 9
            ix. Plasma Processing – TRL 9
            x. Thermal Management – TRL 9
      B. Anticipated positive externalities or synergies
            i. Capacity Utilization
            ii. Supply Chains
            iii. Scarcity Economics
            iv. New Strategies
            v. Waste Valorization
            vi. Feedback

Application of supercritical CO2 (SCO2) Brayton-cycle power conversion system has been investigated for small modular light water reactors. Due to sharp changes in density and thermal properties near the pseudo-critical region, controlling the SCO2 Brayton cycle presents unique challenges in nuclear power applications. A dynamic simulation code (SCPS) based on real-gas and momentum integral model developed at MIT was used to evaluate control strategies for a small modular pressurized light water reactor equipped with a compact SCO2 power conversion system (PCS) with power output ranging from 5MW to 20MW electrical. The NIST REFPROP subroutines and tables were seamlessly integrated with the code to evaluate supercritical CO2 properties. The single-shaft SCO2 PCS consists of a radial compressor and turbine power train and three HEATRIC™ Printed Circuit Heat Exchangers for the intermediate, recuperator, and precooler heat exchangers. The Reactor Coolant System of the small modular reactor (SMR) is modeled after a scaled-down commercial Westinghouse PWR. Using classical control mechanisms applied in light water reactors, control strategies were developed to maintain the compressor inlet conditions away from the pseudo-critical region to avoid compressor surge instabilities. Off-design characteristic curves for turbomachinery were used for real gas machines, since the actual design curves for the SCO2 turbomachinery were not available. The SCO2/PCS control systems were tuned and tested for a wide range of operational transients from 20% power changes up to 50% loss of load. Simulation test results showed that successful application of a compact SCO2 PCS for small modular pressurized light water reactors is possible.

This presentation will provide an overview of the U.S. military's initiatives to develop small terrestrial nuclear power systems since the 1950s, with a focus on recent and ongoing studies to assess the feasibility of reactors for either critical installations or forward and remote bases. Additionally, considerations related to military base energy demands, technology development, policy and diplomatic considerations that impact the attractiveness of developing small reactors for terrestrial military applications will be discussed.
PDF available at: http://www.dtic.mil/ndia/2015power/18004Strogen.pdf

The study presents an experimental investigation of a thermal energy storage vessel for load-shifting purposes. The new heat storage vessel is a plate-type heat exchanger unit with water as the working fluid and a phase change material (PCM) as the energy storage medium. The thermal characteristics of the heat exchanger such as heat transfer coefficient, effectiveness, efficiency, water exit temperature, heat storage rate, total energy storage capacity and storage time were experimentally evaluated as a function of various inlet conditions. The compact parallel plate design showed an enhanced the performance compared to conventional storage systems with an effectiveness up to 83.1% even when a PCM of low thermal conductivity is used. The proposed phase change energy storage system not only can deliver substantial benefits as a thermal energy storage medium, but also provides cost savings in infrastructure, equipment, and maintenance/operations compared to conventional systems.

Is smaller smarter for tomorrow's nuclear weapon and energy technology innovations? This Forbes article examines visions for future small modular reactors and B61-12 nuclear bombs. http://www.forbes.com/sites/energysource/2016/10/25/a-smaller-future-for-nuclear-weapons-and-power-plants-holds-promise-and-peril/#48cd0d7b4d86

Undoubtedly, interest in small modular reactors (SMRs) continues to grow as an option for future power generation and energy security. SMRs are small or medium size reactors (maximum 700 MWe of capacity) that adopt the modularization of its components, by which the structures, systems, and components are shop-fabricated then shipped and assembled on site, thus the construction time for SMRs can be substantially reduced. SMRs with pre-fabricated modules can expedite the construction of a single large nuclear power plant in the same site. SMRs can be installed underground, which improves containment and security, but may hinder emergency access.

: This presentation will provide an overview of the military's initiatives to develop small terrestrial reactors since the 1950s, with a focus on recent and ongoing studies to assess the feasibility of reactors for either critical installations or remote bases. Additionally, I will discuss examples of military base energy demand, technology development, and policy considerations that impact the attractiveness of developing small reactors for terrestrial military applications.