Small Modular Reactor (SMR)

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Effect Analysis of Volume Fraction of Nanofluid Al2O3 Water on Natural Convection Heat Transfer Coefficient in Small Modular Reactor

Effect Analysis of Volume Fraction of Nanofluid Al2O3 Water on Natural Convection Heat Transfer Coefficient in Small Modular Reactor

Development and use of nuclear energy is currently growing very rapidly, in order to achieve in- creasingly advanced technology, both in terms of design, economic factors and safety factors. Thermal-hydraulics aspects of nuclear reactors should be done with calculation and near-perfect condition. Including today began development of a nuclear reactor with low power below 300 MW, or commonly called the Small Modular Reactor (SMR). One is CAREM-25 developed by Argentina with a power of 25 MW, where in CAREM already using natural circulation system and the use of nanofluid as coolant fluid. In this research, analytic modeling of thermal-hydraulics nuclear reac- tor SMR CAREM-25, when the nanofluid Al 2 O 3 -Water used as cooling fluid in the cooling system of a

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Comparison of Small Modular Reactor and Large Nuclear Reactor Fuel Cost

Comparison of Small Modular Reactor and Large Nuclear Reactor Fuel Cost

In this paper, five SMRs based on LWRs were chosen. All SMR reactors in the study are still in pre-build or pre-licensing stages, so the design characteristics are nominal and subject to change by their designers. The five other PWR-derived designs for near term land deployment in this study are: NuScale, mPower, SMART, the Westinghouse SMR, and HI-SMUR. The NuScale power reactor is a 45 MWe reactor based on a PWR design to be installed underground with up to six units sharing a common housing [9]. The B&W mPower reactor was announced to be installed in modules of 125 MWe with a long operating cycle between refuelings [10]. The South Korean SMART (System-integrated Modular Advanced ReacTor) is being developed by KAERI with a thermal power of 330 MWt to be used for both electric generation and water desalination or other process heat applications [11]. The Westinghouse Small Modular Reactor (W-SMR) builds upon the design concepts of the much larger AP1000 reactor currently under construction in China and the United States. The Westinghouse SMR was announced to be a 200 MWe integral pressurized water reactor using a derivative of AP 1000 fuel [12]. Holtec Inherently Safe Modular Underground Reactor, (HI-SMUR) was announced to be a 140 MWe reactor design does not require coolant pumps as it relies on natural convection. It does not depend on off-site power for safe shutdown and thus qualifies as inherently safe. As its name implies, the HI-SMUR is to be built underground [13]. The HI-SMUR is not considered an integral PWR because its steam generators are not in- tegrated into the reactor vessel.

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Self-Consolidating Ultra-High Performance Concrete for Small Modular Reactor Construction

Self-Consolidating Ultra-High Performance Concrete for Small Modular Reactor Construction

Small modular reactors (SMR) allow for faster onsite construction, increase nuclear material security, and provide a flexible and cost-effective power source. SMR can be factory-built as modular components, and shipped to desired locations for fast assembly. This study developed a new type of ultra-high performance concrete (UHPC) which features a compressive strength higher than 150 MPa and self-consolidating characteristics desired for SMR modular construction. With a high strength and dense microstructure, it will facilitate rapid construction of steel plate-concrete (SC) beams and walls with thinner and lighter modules, and can withstand the harsh environments and mechanical loads anticipated during the service life of nuclear power plants. The self-consolidating characteristics are crucial for fast construction and assembly of SC modules with reduced labor costs and improved quality. This paper describes the development and characterization of self-consolidating UHPC, its large-scale processing techniques with conventional equipment, and the ongoing work on the structural mechanics of SC modules made of self- consolidating UHPC.

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Transportation of small modular reactor modules: What do the experts say?

Transportation of small modular reactor modules: What do the experts say?

2.1 Modularization: what it is and its implications Modularization is the process of converting the design and construction of a monolithic plant into a plant that facilitates factory fabrication of modules for shipment and installation in the field as complete assemblies (GIF/EMWG, 2007). Several papers deal with the costs and benefit of modularization (De La Torre, 1994; Azhar, et al., 2012; Bondi, et al., 2016; Upadhyay, et al., 2016). Most of these references are qualitative, like the recent review of modularization in the nuclear industry (Upadhyay, 2016). Factory fabrication is usually cheaper than site fabrication, but the costs associated with shipping of modules to the site must also be considered. Smaller plants can take better advantage of modularization since it is possible to have a greater percentage of factory- made components. Although there are a number of works in the literature describing the qualitative advantages of modularization, only a few of them are able to quantify the underlying advantages. (Mignacca, et al., 2018) provide a summary of the quantitative information about two key implications of modularization in infrastructure: schedule reduction and cost saving. Therefore, modularization implies factory production, which in turn implies transportation of large, complex and fragile modules from the factory to the site. According to (Vegel, et al., 2017), SMRs will be in the factory for the first two years (build time and testing), and in the last year will be transported and installed on site. However, the literature about SMR modules transportation is almost inexistent. Conversely, in other sectors (e.g. Oil & Gas), the experience on modules transportation is much greater.

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Stress Test Seismic Motions For Nuclear Installations

Stress Test Seismic Motions For Nuclear Installations

The complete 3C seismic motions from inclined plane body waves and surface waves with variation in incident angle, frequency and intensities are developed using wave potential formulation. The 3C seismic excitations are then applied to SSI system by domain reduction method (DRM). Dynamic response of SSI system is simulated through finite element analysis. High frequency stress test motions are obtained analytically using Thompson-Haskell propagator matrix technique. Frequency content is only limited by the mesh size of finite element model of SSI system. Proposed methodology is implemented in the Real ESSI Simulator and is illustrated through stress tests of a deeply embedded small modular reactor (SMR). Different stress test responses of SMR are compared. Suggestions for improved design of NIs are given. INTRODUCTION

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Ant colony based optimization algorithm for the
Mobile ad hoc Network Routing Problems
based on SMR Protocol (ACO-SMR)

Ant colony based optimization algorithm for the Mobile ad hoc Network Routing Problems based on SMR Protocol (ACO-SMR)

Mobile ad hoc networks (MANETs) consist of a collection of wireless mobile nodes which dynamically exchange data among themselves without the reliance on a fixed base station or a wired backbone network. All nodes are mobile and can be connected dynamically in an arbitrary manner. Multi hop, mobility, large network size combined with device heterogeneity, bandwidth and battery power constrain make the design of adequate routing protocols a major challenge. Because of these characteristics, path connecting source nodes with destination may be very unstable and go down at any time, making communication over ad hoc networks difficult. Earlier research has proposed several uni-path routing protocols specifically on MANET. In single routing, only a single route is used between a source and destination node. Single path routing protocols cause increases the call blocking probability and decreases overall network utilization. Additionally, single path protocol can increase end-to-end delay and packet loss rate. To alleviate these problems, new multipath routing algorithm for MANETs is proposed, which combines the idea of ant colony optimization with Split Multipath Routing (SMR) protocol. Ant colony optimization Split Multipath Routing (ACO-SMR) is based on swarm intelligence and especially on the ant colony based meta heuristic. The proposed algorithm will improved the performance of the network such as delay and packet delivery ratio than traditional routing algorithms.

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Hiroshima survivors exposed to very low doses of A-bomb primary radiation showed a high risk for cancers

Hiroshima survivors exposed to very low doses of A-bomb primary radiation showed a high risk for cancers

The results of our study would seem to confirm this: even people in the lowest dose category were shown to be subject to a significantly higher level of risk than those in the control group. The significant difference in risk between the two groups is thought to be due either to a difference in the evaluation of risks from initial radiation or (perhaps in addition to) to a difference in the evaluation of risks from residual radiation, and it can be explained as follows. If DS86 underestimated the level of radiation to which survivors were exposed in more remote areas, then those survivors included in the very low and low categories must have in fact received a higher initial dose of radiation than was formerly considered. This would explain the high SMR among the very low category within the LSS group. Assuming, on the other hand, that the assumptions relating to initial radiation doses in DS86 were correct, this would indicate that the initial radiation in the very low dose cat- egory in fact carried an increased risk, over and above that which could be assumed based on the high radiation area data. Additionally, the evaluations in DS86 do not take into account residual radiation, which could be the basic reason for the disparity. It cannot be denied that even survivors in the very low category may have been subject to additional radioactive fallout and may have breathed in or swallowed induced radioactive substances in the vicinity of the hypocenter [15–18].

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Challenges Associated with Hydrogen Generation Modeling in Small Modular Reactors

Challenges Associated with Hydrogen Generation Modeling in Small Modular Reactors

Computer codes to evaluate hydrogen generation include GOTHIC, MAAP5 and MELCOR which allow the analyst to optimize the design of hydrogen control equipment for design basis and severe accidents. In this paper, a scoping or exploratory EXCEL model is developed as a tool to quickly estimate the relative duration and magnitude of hydrogen release and containment pressurization for a typical SMR. Use of hydrogen mitigation systems in a SMR using realistic releases can potentially eliminate the plant operational and safety issues associated with an inerted containment, and also provide measures to address the challenges of severe accident loads.

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Secretion Modification Region-Derived Peptide Disrupts HIV-1 Nef's Interaction with Mortalin and Blocks Virus and Nef Exosome Release

Secretion Modification Region-Derived Peptide Disrupts HIV-1 Nef's Interaction with Mortalin and Blocks Virus and Nef Exosome Release

DNA constructs. The following clones were constructed as described previously (2) using the HIV-1 NL4-3 nef construct in expression vector pQBI-Nef-GFP (wtNef-GFP; Quantum Biotechnologies, Montreal, Can- ada) as a template: (i) SMR mutant Nef-GFP containing a single alanine replacement of the first amino acid of the SMR motif sufficient for abol- ishing Nef secretion (AGFPV/1A); (ii) SMR mutant Nef-GFP containing alanine replacements of all five amino acids of the SMR motif (SMR/5A); (iii) GFP alone; (iv) wild-type Nef with GFP replaced by mCherry (wtNef- RFP) from the pmCherry prokaryotic expression vector (Clontech Labo- ratories, Inc., Mountain View, CA). The fusion proteins were expressed in Jurkat cells under the control of the cytomegalovirus promoter in pQBI. The Myc-DDK-tagged open reading frame clone of mortalin in the ex- pression vector pCMV6 Entry (mortalin-FLAG) was obtained from Ori- Gene Technologies, Inc. (Rockville, MD). The BLOCK-iT Pol II miR RNAi expression vector kit (Invitrogen Corporation, Carlsbad, CA) and the HSPA9 (mortalin) primers Hmi 408224 to Hmi 408227 (Invitrogen) were used to generate an expression vector (miR-mortalin) that expresses mortalin microRNA (miRNA; miR). The kit also contained a correspond- ing pcDNA6.2-GW/miR-neg control plasmid (miR-neg) predicted not to target any known vertebrate gene, which was used as a negative control. The wild-type HIV-1 proviral R7 clone (1) expresses a full-length, replication-competent, infectious virus whose Nef differs from that of NL4-3’s by one amino acid (from 15 A in NL4-3 to 15 T in R7). R7 was a

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Load following with Small Modular Reactors (SMR): A real options analysis

Load following with Small Modular Reactors (SMR): A real options analysis

NPP are base-load plants but present and future scenarios with significant share of renewable power in the generation portfolios require them to operate in a load following mode. NPP are capital -intensive plants with an operation cost almost independent from the amount of electricity generated. To maximise profitability and safety NPP need to maximize their load factor. Performing the load following by reducing the power rate in the primary side has two drawbacks: it introduces thermo-mechanical stresses and postpones the investment pay- back time. Therefore, the goal of this work is to assess the option of using the excess thermal power for cogeneration purposes, thus improving the investment economics and the capability to adapt the electricity production to the market demand. In particular the research focuses on multiple SMR because they offer the possibility to split the total power of the power station: some units may be fully dedicated to the electricity production (during off-peak hours) and some others to the cogeneration of alternative products (i.e. desalinated water). This enables the electricity load following at site level, while keeping all the plants at maximum efficiency. The load following with large units is less attractive since off-design operation at reduced power rates decrease the overall conversion efficiency.

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A Method for Visualizing Independent Spatio-Temporal Patterns of Brain Activity

A Method for Visualizing Independent Spatio-Temporal Patterns of Brain Activity

distinguishes the actual independent spatio-temporal mor- phologies indicative of the di ff erent mental states without prior knowledge of the SMR characteristics. As with any application of ICA where exact number of sources is not known, it is difficult to speculate about the significance of the resulting ISTPs. Nevertheless, it is interesting that the ISTPs having the highest correlation with the target position often exhibit the classical arch-shaped μ-rhythm pattern [20], suggesting that there is a preferred amplitude/phase synchronization between the fundamental SMR frequency and the harmonics.

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Small modular reactors: A comprehensive overview of their economics and strategic aspects

Small modular reactors: A comprehensive overview of their economics and strategic aspects

commonly termed ‘‘Small and Medium-sized Reactors’’ or “Small Modular Reactors” (SMR) representing those with an electrical output less than 700 MWe. For the purposes here, it will be assumed that a “Large Reactor” (LR) counterpart has a power output >700 MWe. The term SMR includes the nuclear options along with the remainder of the plant support infrastructure and equipment, namely the steam generator, turbine and fuel storage facilities, if necessary, and can be deployed as multiple units on the same site to increase total power output. Several SMR designs (detailed in [9]) are currently at different stages of development around the globe. Ingersoll [10] provides a good summary of the innovative feature of these; “reactor designs that are deliberately small, i.e. designs that do not scale to large sizes but rather capitalize on their smallness to achieve specific performance characteristics.”.

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Social differences in avoidable mortality between small areas of 15 European cities: an ecological study

Social differences in avoidable mortality between small areas of 15 European cities: an ecological study

The results from our international comparison across Europe cannot be directly compared to previous findings because our study is the first to provide such results. However, the lack of a strong pattern of different magni- tudes of health inequalities between different regions of Europe is surprising and requires some tentative expla- nations because at the individual level the magnitude of health inequality differs across countries and European regions. One previous study compared the effect of small area unemployment on all-cause mortality between cities from six different countries [28]. The authors concluded that this effect is not substantially modified by the coun- try, although one could have expected such international differences based on differences in absolute levels (and ranges) of deprivation or based on different national policies to address health inequalities. We tend to agree to their interpretation that there seems to be a general

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Tunable Sign Change of Spin Hall Magnetoresistance in Pt/NiO/YIG Structures

Tunable Sign Change of Spin Hall Magnetoresistance in Pt/NiO/YIG Structures

when an antiferromagnetic (AFM) insulator, in this case NiO, is inserted between Pt and YIG [20]. The negative SMR was also found to revert to the conventional positive sign at higher temperatures. Signal contamination from other magnetoresistances such as AMR was excluded by a systematic field angle dependence measurement. This re- sult challenges the present understanding of SMR. Since the SMR does not change its sign in the Pt/YIG bilayer structure, the NiO layer must be the cause. However, it is not clear why NiO should give a negative SMR since antiferromagnets are thought only to affect the efficiency of the spin communication between Pt and YIG [21–26]. In this letter, we report the temperature dependence of SMR in Pt/NiO/YIG structures with different thick- nesses of NiO. The temperature at which the SMR be- comes negative is found to depend on the NiO thickness. The anomalous negative SMR at low temperatures is ex- plained from a ‘spin-flop’ configuration whereby the N´eel order of the NiO is perpendicularly coupled to the mag- netization of YIG [27]. As the spin conductivity of NiO increases with increasing temperature [24–26], the mo- ments of the YIG beneath have an increasing influence on the total SMR signal. The positive SMR contribution from YIG competes the negative SMR from NiO. At the sign change, the competition leads to a vanishing SMR. Above, in the high temperature regime, the positive SMR of the YIG dominates. We introduce a phenomenological model to describe the competition between the positive and negative SMR contributions, which reproduces the NiO thickness dependent SMR sign change behaviors in Pt/NiO/YIG.

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Mitochondrial acclimation potential to ocean acidification and warming of Polar cod (Boreogadus saida) and Atlantic cod (Gadus morhua)

Mitochondrial acclimation potential to ocean acidification and warming of Polar cod (Boreogadus saida) and Atlantic cod (Gadus morhua)

Polar cod is a cold adapted species and the constraint on cardiac mitochondrial metabolism at 8 °C, concomi- tant with increased mortality indicates that the animal’s thermal window matches its current habitat temperature range. In contrast, adult NEAC show the ability to broaden their thermal window beyond the present sub- Arctic habitat temperatures (see above). Because of the habitat temperature range of the two species is similarly wide but shifted to lower temperatures in Polar cod, combined with the high metabolic baseline cost (SMR) of Polar cod the two species may be classified as cold- adapted (Polar cod) or cold-acclimated (NEAC) eurytherms. NEAC appear to be much more plastic than Polar cod, thus, Polar cod may be more vulnerable to future ocean conditions than NEAC.

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Coupling and Design of a Thermal Energy Storage System for Small Modular Reactors.

Coupling and Design of a Thermal Energy Storage System for Small Modular Reactors.

The reactor system was assumed to have sufficient capacity to meet 100% load on the most extreme summer day. The run shown above is representative of a typical summer day [1]. As a result, there will always be some bypass demand. Bypass demand goes as nominal reactor output-turbine demand. For the run shown we have bypass ranging from ~45% bypass down to ~7-8% bypass. Figure 4.13 shows that we are able to meet bypass demand as the valves never fully open or shut. Figure 4.14 shows the operating pressure at 45% bypass at the 750 psi design pressure, and over the course of the run reaches a minimum of ~700psi. As the pressure does not fall below 680psi, the shell side saturation temperature remains above the tube side set point temperature of 500F. Should the pressure in the IHX fall below this value the set point temperature on the tube side could not be reached. Further, the pressure in the IHX never reaches the setpoint of 780psi at which point the Pressure Relief Valves would open. Since the Pressure Relief Valves do not open this means zero energy is bypassing the TES system through the PRV’s.

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Analysis Of Power Characteristics Of Model Thermoelectric Generator (TEG) Small Modular

Analysis Of Power Characteristics Of Model Thermoelectric Generator (TEG) Small Modular

Based on test results conducted thermoelectric characterization can be drawn the conclusion that the results of characterization studies thermoelectric generator with two thermoelectric modules are installed in series in generating power output of thermoelectric plants is approximately 3.01 volt thermoelectric structure has a role to generate a certain voltage or strong currents. To generate a high voltage Peltier should be arranged in series, while the strong current to get high, thermoelectric must be arranged in parallel. Thermoelectric in series to produce greater power than the thermoelectric arranged in parallel. Broadly speaking, the powers generated in thermoelectric power plants are still quite small. However, it has been shown that the thermoelectric plants have a bright prospect in the future as an alternative electrical energy. So, wherever there is waste heat, thermoelectric plants can transform waste heat into electrical power.

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Incidence and excess mortality of hip fracture in young adults: a nationwide population based cohort study

Incidence and excess mortality of hip fracture in young adults: a nationwide population based cohort study

This study analyzed several outcomes, namely, (a) an- nual incidence of hip fracture; (b) annual mortality; (c) annual standardized mortality ratio (SMR); (d) cumula- tive mortality; (e) follow-up SMR; and (f ) risk factors of mortality, over ten years after hip fracture among young adults. Annual mortality and cumulative mortality are absolute rates indicating the occurrence proportion of death among these study subjects. Meanwhile, annual SMR and follow-up SMR are relative mortality rates in- dicating the relative risk of death of our study popula- tion compared to that in the corresponding general population. Overall survival time was defined as the dur- ation from the index day to the death day. Subjects alive

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Relevance of the type III error in epidemiological maps

Relevance of the type III error in epidemiological maps

For the unstructured model and a cut-off probability of 0.8 the q-values are plotted against the (assumed) true SMR values in Figure 4a. Apart from a general inclin- ation in favour of higher q-values, there is hardly any ap- preciable difference compared to the results for the crude SMR estimator (Figure 3). Increasing the cut-off probability to 0.975 decreases q-values in the main (Figure 4b). Some districts with small numbers of expected cases constitute exceptions. This is due to the definition of the q-value, which relates "significant" effect reversing to all "significant" results. When the cut-off probability is increased, the proportion of "significant" results in any direction will generally decrease and the proportion of "significantly" effect-reversed results is expected to decrease even further. The latter is not al- ways the case for some districts with small numbers of expected cases.

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Model Thermoelectric Generator (TEG) Small Modular As Micro Electricity Plant At Indonesia Part 1: Design And Material

Model Thermoelectric Generator (TEG) Small Modular As Micro Electricity Plant At Indonesia Part 1: Design And Material

highly dependent on temperature, temperature gradient is not only work, but also tilapia absolute temperature. Thermoelectric devices can be used to generate electrical energy direct current (DC) when the temperature difference. However, currently available thermoelectric materials have ZT <1 and the efficiency of the device to generate electrical energy rarely exceed 5%. This limits the performance of thermoelectric generators for applications where the requirements for remote operation, test stand, there are no moving parts and no noise has exceeded aspects worse than the expensive cost and low conversion efficiency. This tends to limit the application of thermoelectric technology for small cooling systems, low power, or special cooling or power applications. These systems generally require power or a small flow of heat energy. Maximum efficiency of thermoelectric devices in power plants is determined by equation (4):

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