bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of poor food quality on copepod growth are dose dependent and non‐reversible
Authors: Malzahn Arne M. , Boersma Maarten
Published: February 2012

Herbivores regularly face imbalanced diets on a variety of timescales. They respond to such diets with reductions in growth and reproduction. The effect of exposure time to poor quality diets and recovery potential in herbivores has yet not been intensively studied. In order to investigate the response of herbivores growth and nutritional condition to phosphorus limited algal food, we fed the copepod Acartia tonsa with the autotrophic flagellate Rhodomonas salina, which was cultured towards high and low phosphorus content. To test the effect of the duration of the exposure to low and high P food on copepod growth, we also switched a subset of the copepods from high P to low P food for two to 12 days before putting them back on their original diet. Phosphorus limited prey clearly reduced copepod nutritional condition, expressed as their RNA:DNA ratio and consequently their growth rates. Several days after re‐feeding on high P algae, the copepods were able to reach growth rates comparable to the control groups, but they were in no case able to over shoot the growth rates of the control groups. A dose of two days feeding on low P algae resulted in slightly less than one stage growth reduction compared to copepods exclusively reared on high P algae. Our results show that phosphorus limited food drastically reduces secondary production, and no compensatory growth occurs in the investigated copepod species. Hence, even short term exposure of herbivores to poor food has a lasting effect on secondary production.
Faster pulmonary oxygen uptake kinetics in children vs adults due to enhancements in oxygen delivery and extraction
Authors: Leclair E. , Berthoin S. , Borel B. , Thevenet D. , Carter H. , Baquet G. , Mucci P.
Published: February 2012

This study aimed to examine if the faster pulmonary oxygen uptake (VO2p) phase 2 in children could be explained by increased O
2 availability or extraction at the muscle level. For that purpose, O
2 availability and extraction were assessed using deoxyhemoglobin (HHb) estimated by near‐infrared spectroscopy during moderate‐intensity constant load cycling exercise in children and young adults. Eleven prepubertal boys and 12 men volunteered to participate in the study. They performed one maximal graded exercise to determine the power associated with the gas exchange threshold (GET) and four constant load exercises at 90% of GET. VO2p and HHb were continuously monitored. VO2p, HHb, and estimated capillary blood flow () kinetics were modelled after a time delay and characterized by the time to achieve 63% of the amplitude (τ) and by mean response time (MRT: time delay + τ), respectively. Mean values of τ for VO2p (P < 0.001), of MRT for HHb (P < 0.01) and of MRT for (P < 0.001) were significantly shorter in children. Faster VO2p kinetics have been shown in children; these appear due to both faster O
2 extraction and delivery kinetics as indicated by faster HHb and kinetics, respectively.
Forgiveness and Reconciliation in Emotionally Focused Therapy for Couples: The Client Change Process and Therapist Interventions
Authors: Zuccarini Dino , Johnson Susan M. , Dalgleish Tracy L. , Makinen Judy A.
Published: February 2012

This article presents psychotherapy process research findings related to the forgiveness and reconciliation model, known as the Attachment Injury Resolution Model (AIRM), within the context of emotionally focused therapy for couples (EFT). Outcomes for EFT as an intervention for general relationship distress and AIRM have been successfully tested. Audiotapes of nine resolved and nine nonresolved EFT couple cases were used to study the client change process, the validity of AIRM, and EFT interventions used at each stage of the model. Study findings suggest resolved couple clients engaged deeply with their internal experience were more deliberate and controlled in their processing and more affiliative in their interpersonal responses in comparison with nonresolved couples. Resolved versus nonresolved client in‐session performances were discriminated on the basis of four model components. These were associated with significant shifts from secondary reactive emotions to primary attachment–related emotional processing of the injurious incident and with interactions that focus on shaping emotional responsiveness. Key EFT interventions employed in successful attachment injury resolution are also identified.
Health‐Enhancing Physical Activity: Associations with Markers of Well‐Being
Authors: Mack Diane E. , Wilson Philip M. , Gunnell Katie E. , Gilchrist Jenna D. , Kowalski Kent C. , Crocker Peter R.E.
Published: February 2012

Background: The association between health‐enhancing physical activity (HEPA) and well‐being was investigated across a cross‐sectional (Study 1; N = 243) and a longitudinal, two‐wave (Study 2; N = 198) design. Study 2 further examined the role played by fulfilling basic psychological needs in terms of understanding the mechanisms via which HEPA is associated with well‐being. Methods: Women enrolled in undergraduate courses were surveyed. Results: In general, greater HEPA was associated with greater well‐being (Study 1; rs ranged from .03 to .25). Change score analyses revealed that increased HEPA positively predicted well‐being (Study 2; R2adj = 0.03 to 0.15) with psychological need fulfilment underpinning this relationship. Conclusions: Collectively these findings indicate that increased engagement in health‐enhancing physical activity represents one factor associated with greater well‐being. Continued investigation of basic psychological need fulfilment as one mechanism underpinning the HEPA–well‐being relationship appears justified.
Wild Birds as Sentinels for Multiple Zoonotic Pathogens Along an Urban to Rural Gradient in Greater Chicago, Illinois
Authors: Hamer S. A. , Lehrer E. , Magle S. B.
Published: February 2012

Wild birds are important in the maintenance and transmission of many zoonotic pathogens. With increasing urbanization and the resulting emergence of zoonotic diseases, it is critical to understand the relationships among birds, vectors, zoonotic pathogens, and the urban landscape. Here, we use wild birds as sentinels across a gradient of urbanization to understand the relative risk of diseases caused by three types of zoonotic pathogens: Salmonella pathogens, mosquito‐borne West Nile virus (WNV) and tick‐borne pathogens, including the agents of Lyme disease and human anaplasmosis. Wild birds were captured using mist nets at five sites throughout greater Chicago, Illinois, and blood, faecal and ectoparasite samples were collected for diagnostic testing. A total of 289 birds were captured across all sites. A total of 2.8% of birds harboured Ixodes scapularis– the blacklegged tick – of which 54.5% were infected with the agent of Lyme disease, and none were infected with the agent of human anaplasmosis. All infested birds were from a single site that was relatively less urban. A single bird, captured at the only field site in which supplemental bird feeding was practised within the mist netting zone, was infected with Salmonella enterica subspecies enterica. While no birds harboured WNV in their blood, 3.5% of birds were seropositive, and birds from more urban sites had higher exposure to the virus than those from less urban sites. Our results demonstrate the presence of multiple bird‐borne zoonotic pathogens across a gradient of urbanization and provide an assessment of potential public health risks to the high‐density human populations within the area.
The Effect of Target Language and Code‐Switching on the Grammatical Performance and Perceptions of Elementary‐Level College French Students
Authors: Viakinnou‐Brinson Lucie , Herron Carol , Cole Steven P. , Haight Carrie
Published: February 2012

Grammar instruction is at the center of the target language (TL) and code‐switching debate. Discussion revolves around whether grammar should be taught in the TL or using the TL and the native language (L1). This study investigated the effects of French‐only grammar instruction and French/English grammar instruction on elementary‐level students’ grammar performance. The study also examined students’ instructional preference and perceptions of the use of either approach to teach grammar and French in general. Grammar test score increases were significantly greater for the French‐only condition, and posttest grammar scores were significantly higher for the French‐only condition. Qualitative findings suggested that although a majority of students expressed a preference for learning French grammar with the support of English, they recognized the benefits of a TL approach.
Small Modular Molten Salt Reactor (SM-MSR)
Authors: Sabharwall Piyush , Kim Eung Soo , Mckellar Michael , Patterson Mike
Published: February 2012

The strategic goal of the Small Modular Molten Salt Reactor (SM-MSR) is to broaden the environmental and economic benefits of nuclear energy in the United States by producing power to meet growing energy demands and demonstrating its applicability to market sectors not being served by light water reactors. Of primary importance is demonstrating that the SM-MSR can be operated safely and compete economically with larger reactors. Reactor outlet temperatures (ROTs) of SM-MSRs will likely be much higher (around 700°C) than light water reactors, thereby increasing the efficiency of electricity production and potentially providing process heat for industrial applications, which will help offset the higher per kilowatt costs generally associated with smaller reactors, making the SM-MSR more economically competitive. This paper compares thermal power cycles for given ROT, compares thermal performance using figure of merits and sensitivity study and discusses the comparative advantages of SM-MSRs.
Reducing Potential for Stress Corrosion Cracking During Design and Fabrication of Small Modular Reactors
Authors: Hackel Lloyd A. , Dane C. Brent , Rankin Jon , Harris Fritz , Truong Chanh
Published: February 2012

Reactor designs employ the best materials available such as Alloy 600 and Alloy 690 to resist stress corrosion cracking (SCC); yet the problem has continued to exist. As SCC is driven by three main contributors, susceptible material, corrosive environment and existence of tensile stress, eliminating any one can greatly improve the situation. In this paper we discuss a laser peening process for the nuclear industry that can convert areas of tensile stress to deep levels of compression. Laser peening induces deep levels of plasticity into materials resulting in compressive residual stress to depths of 0.100 inches (2.5 mm) or deeper. This enables increased fatigue strength and lifetimes and greatly enhances resistance to stress corrosion cracking. The deep plasticity closes the inter-granular boundaries and induces a deep layer of compressive stress dramatically improving the stress corrosion cracking (SCC) resistance of components subjected to tensile loading in a corrosive environment. The deeper plasticity generated by laser peening can be contrasted to a depth of only 0.010 inches (0.25 mm) typically achieved with conventional shot peening, a beneficial and widely used technology. Advances in laser technology have enabled highly reliable, high-rate, cost-effective processing that has made a major impact in aerospace; thousands of parts and large scale structures have been and are being treated. Advanced laser beam delivery to components has enabled cost-effective field applications. The peening is done without physical contact with the component. The technology has been approved by organizations such as the FAA, EASA and USAF and deployed to enhance lifetime of key structural components on the F-22 fighter. Component faducials on a structure are first visually detected by a camera and alignment laser and then the main laser beam is automatically aligned to the component. The technology has the potential to serve a broad range of fielded industrial applications including oil and gas lines, on-board ship applications, nuclear power plants, upstream exploration and recovery, and downstream oil refining. We will discuss examples of advanced fatigue and corrosion resistance in steels provided by the laser peening technology as well as the hardware now available for field use. The laser peening technology enables SCC mitigation via engineered compressive residual stress to be considered much more seriously at the design level for reactors.
A Supercritical Water-Cooled Small Modular Reactor
Authors: Duffey R. , Leung L. K. H. , Martin D. , Sur B. , Yetisir M.
Published: February 2012

A new small modular reactor (SMR) is proposed for a 300 MW(e) nuclear generating station. It is referred as the SuperSafe© Reactor (SSR) and is a scaled down version of the Canadian supercritical water-cooled reactor (SCWR), which is designed to operate at supercritical conditions (pressure of 25 MPa and fluid temperature of 625°C) at the turbine inlet with high cycle efficiencies (∼45%). The supercritical turbine technology and associated components used in the balance of plant (BOP) are similar to those in existing supercritical fossil-fired plants. The reactor core consists of fuel channels, which are submerged in a subcooled heavy-water moderator pool inside a low-pressure calandria vessel. Each fuel channel consists of a pressure tube and a ceramic insulator enclosed inside a porous stainless steel sleeve. The moderator provides cooling to fuel channels under normal operation and postulated accident scenarios. This design feature enables the use of a flash-driven passive moderator cooling — an inherent safety feature of the proposed design. A major safety goal is to achieve a passive “no core melt” configuration for the channels and fuel.
Canadian Nuclear Safety Commission: Readiness to Regulate SMRs in Canada
Authors: Herstead S. , de Vos M. , Cook S.
Published: February 2012

The success of any new build project is reliant upon all stakeholders — applicants, vendors, contractors and regulatory agencies — being ready to do their part. Over the past several years, the Canadian Nuclear Safety Commission (CNSC) has been working to ensure that it has the appropriate regulatory framework and internal processes in place for the timely and efficient licensing of all types of reactor, regardless of size. This effort has resulted in several new regulatory documents and internal processes including pre-project vendor design reviews. The CNSC’s general nuclear safety objective requires that nuclear facilities be designed and operated in a manner that will protect the health, safety and security of persons and the environment from unreasonable risk, and to implement Canada’s international commitments on the peaceful use of nuclear energy. To achieve this objective, the regulatory approach strikes a balance between pure performance-based regulation and prescriptive-based regulation. By utilizing this approach, CNSC seeks to ensure a regulatory environment exists that encourages innovation within the nuclear industry without compromising the high standards necessary for safety. The CNSC is applying a technology neutral approach as part of its continuing work to update its regulatory framework and achieve clarity of its requirements. A reactor power threshold of approximately 200 MW(th) has been chosen to distinguish between large and small reactors. It is recognized that some Small Modular Reactors (SMRs) will be larger than 200 MW(th), so a graded approach to achieving safety is still possible even though Nuclear Power Plant design and safety requirements will apply. Design requirements for large reactors are established through two main regulatory documents. These are RD-337 Design for New Nuclear Power Plants, and RD-310 Safety Analysis for Nuclear Power Plants. For reactors below 200 MW(th), the CNSC allows additional flexibility in the use of a graded approach to achieving safety in two new regulatory documents: RD-367 Design of Small Reactors and RD-308 Deterministic Safety Analysis for Small Reactors. The CNSC offers a pre-licensing vendor design review as an optional service for reactor facility designs. This review process is intended to provide early identification and resolution of potential regulatory or technical issues in the design process, particularly those that could result in significant changes to the design or analysis. The process aims to increase regulatory certainty and ultimately contribute to public safety. This paper outlines the CNSC’s expectations for applicant and vendor readiness and discusses the process for pre-licensing reviews which allows vendors and applicants to understand their readiness for licensing.
Radiation Resistance of Rubber Compound for Gasket
Authors: Nakano Mitsuyuki , Sasaki Haruko , Ono Harumi
Published: February 2012

Seals of small and medium modular reactors are considered as not important components compared with seals for the large modular reactors which are current-generation plants. Leakage of seals has been a safety concern, however seal maintenance and replacement are costly and time consuming for the current-generation plants. Therefore, integral designs of small and medium modular reactors eliminate the need for seals. However it is impossible to eliminate seals completely from the detail design and equipments. Seals consisting of organic materials are estimated as serious damaged components at design basis accident (DBA). Especially it is no exaggeration to say that rubber gaskets are weakest gasket at DBA. In the point of view we must know about behavior of rubber deterioration under condition at DBA. It is very important to select rubber compound from a viewpoint of not only adequate rubber that has characteristic required for each specification but also consideration about rubber deterioration under condition at normal plant operation and DBA. However rubber for gasket has not been selected based on precise studies with enough data concerned about the rubber deterioration because there have been less studies in the world. From compression set test, swelling test, and Fourier transform infrared spectroscopy (FT-IR) analysis, it has been indicated that chemical structure of both Ethylene propylene diene monomer rubber (EPDM) and Silicone rubber might be broken by radiation, and crosslinking of elastomer by radiation might progress at the same time. In fact, EPDM compounds have good results of compression set after radiation exposure and Silicone rubber does not have good results. It had been predicted that breakage and crosslinking of elastomer chemical structure caused by radiation would have been more serious on Silicone rubber. On the other hand, it has been estimated that breakage of chemical structure of Fluoro-rubber is more influenced by crosslinking of elastomer by radiation, than influence by low molecular elastomer caused by deterioration have been generated. From these results it is considered that Fluoro-rubber is weak against radiation compared to another elastomer. If Fluoro-rubber must be chosen because of its high thermal resistance for example, a radiation condition of environment should be considered seriously. Unfortunately we could not find significant correlation between compression set and general properties. However results of elongation at breakage indicates possibility of relationship to compression set.
Promoting US Readiness for Developing the SMR Supply Chain
Authors: Crawford David , Akins Harrison
Published: February 2012

The U.S. Nuclear Infrastructure Council (NIC) is undertaking various initiatives to develop strategies and facilitate U.S. manufacturing readiness in the near-term to meet U.S. and global demands for new nuclear builds. Job creation and clean energy benefits arise from new nuclear builds, and the development of the Small Modular Reactor (SMR) supply chain is critical to realizing these positive attributes of nuclear energy. Opportunities exist for the U.S. nuclear industry to build its SMR supply chain capabilities in order to take advantage of expanded nuclear energy utilization. This presentation will provide, first, a brief overview of the challenges which exist for the development of the domestic SMR supply chain, such as expanding industrial capacity, promoting workforce development, ensuring American competitiveness in the global energy market, resolving licensing issues, and securing financing. Secondly, the presentation will discuss why the United States and, in particular, the nuclear industry should respond to these challenges. This is important in helping to shape the future political debates and form recommendations that will help promote the SMR supply chain industry and its role in expanding the demand and infrastructure for nuclear energy. Finally, the presentation will look at NIC recommendations in the supply chain area to support SMRs and other nuclear power plant deployments.
Safety Assessment Principles Applied to Small Modular Reactors
Authors: Harman Neil F. , Anderson Guy S. , Lillington John N. , Booler Russ V.
Published: February 2012

Much of the attention on small modular reactors (SMRs) has to date been focused on the technology or novel applications, however, this paper tries to set out some thoughts on some of the other issues, or “externalities” within which any SMR proposal must be brought to market. The Paper outlines the UK regulatory regime highlighting differences from that in the US. Regulation in the UK is based on Safety Assessment Principles rather than a prescriptive set of requirements; the amenability of such a regime to assessing novel reactor designs and applications is discussed in general terms. The Paper summarizes the licensing arrangement for nuclear facilities used by the UK nuclear regulator. It goes on to summarize the recent Generic Design Assessment (GDA) programme for new build in the UK in which Serco has been heavily involved. The Safety Assessment Principles reach further than just into the technicalities of engineering design. Two particular areas of interest are picked out: the availability of qualified and experienced personnel and the impact on plant as a result of grid and transmission system issues. With regard to the first of these, in the early days of nuclear power, the UK considered many different reactor designs including gas cooled reactors, fast reactors, heavy water reactors, high temperature reactors and later a small reactor design — the SIR (Safe Integral Reactor) — although this was never built; these are briefly described highlighting any similarities to current proposed small reactor designs and concepts and discussing any lessons that could be learned. Staff in Serco have been involved with all these developments as well as undertaking research in Generation IV concepts. To begin to address the impact on the plant from its interface with the external electricity grid system, the Paper discusses the energy market in the UK (one of the most deregulated), the state of the nuclear industry, the current political landscape as far as nuclear power is concerned, and the prospects for deploying small modular reactors in the UK. It then considers the implications of the European Union’s challenge to decarbonize electricity supply by 2050. Finally, the Paper considers other pertinent issues associated with small reactor concepts and the Safety Assessment Principles. It discusses some of the issues around inspection, given that many of the small reactor concepts are based on underground reactors. Given the smaller size of SMRs, the opportunities for association with novel non-power generating applications are greater than for conventional plant. Some differences associated with these proposals, compared to traditional nuclear power generation, are examined. The paper then also discusses the advantages and disadvantages, as far as safety is concerned, of a farm of small modular reactors compared with a single large reactor.
Synthesis and Analysis of Alpha Silicon Carbide Components for Encapsulation of Fuel Rods and Pellets
Authors: McHugh Kevin M. , Garnier John E. , Griffith George W.
Published: February 2012

The chemical, mechanical and thermal properties of silicon carbide (SiC) along with its low neutron activation make it an attractive material for encapsulating fuel rods and fuel pellets. The alpha phase of SiC has particularly attractive thermal properties. Unfortunately, it requires very high temperature processing and continuous alpha SiC fiber is not available commercially. This paper describes a method for fabricating continuous, composite (SiC/C) fibers as well as monolithic SiC fibers by direct conversion of carbon fibers using SiO vapor at ∼ 1600°C. EDS analysis indicates the converted SiC product contains 1:1 stoichiometric amounts of C and Si. Hexagonal (α) SiC was found to be the dominant crystal structure by x-ray diffraction.
Are SMR a Reasonable Choice for Switzerland? An Application of the INCAS Model
Authors: Boarin Sara , Locatelli Giorgio , Mancini Mauro , Ricotti Marco E.
Published: February 2012

Small countries can represent a suitable market for Small Medium Reactors (SMR). Among them Switzerland is one the more interesting since already hosts five commercial nuclear reactors; three of them are SMR (about 370 MWe) and two are large units (985 and 1165 MWe). Since the oldest units are about 40 year-old the Swiss utilities wereplanning to replace them while adding new nuclear power capacity to the portfolio mix.. Most recently, a radical re-thinking of the country energy policy is taking place as a Fukushima accident’s aftermath. Debate is about abandoning nuclear power and replacing it with renewable new capacity and import. “Economiesuisse, the umbrella organisation for Swiss business, considers a premature abandonment of atomic energy . Without valid alternatives, Economiesuisse warns, abandoning the nuclear option will have serious consequences for Swiss industry”. Also “the environmental organisationsrecognise that the discussion on energy policy — which will really heat up with the parliamentary debate in June — is not solely an ideological one. Financial and economic considerations are likely to make all the difference” (L.Jorio, “What price a future without nuclear energy?”, www.swissinfo.ch, May 17, 2011).An objective and unbiased estimation of the cost of new nuclear power is essential to Policy Makers and a focus on SMR economic potential is a further contribution to the debate. SMR advanced passive safety features may cope with public concerns about safety, which has become a priority. Polimi’s INCAS model has been developed to compare the investment in SMR respect to LR and is able to assess the financial/economic indicators arising from these two alternative investment options. In particular the INCAS model provides the value of IRR (Internal Rate of Return), NPV (Net Present Value), Upfront investment, etc. A stochastic approach to the data elaboration and the implementation of a Montecarlo analysis provide the evaluation of the investment risk profile. Results show that investment returns are comparable for LR and SMR; however SMR require a lower upfront investment, thus representing lower sunk costs and more affordable and scalable investment option than monolithic LR.
Modeling and Phenomenological Aspects of Severe Accidents in Integral Pressurized Water Reactors
Authors: Madni I. K. , Khatib-Rahbar M.
Published: February 2012

This paper focuses on modeling and phenomenological issues relevant to analysis of severe accidents in integral Pressurized Water Reactors (iPWRs). It identifies relevant thermal-hydraulics, melt progression and fission product release and transport phenomena, and discusses the applicability of the MELCOR computer code to modeling of severe accidents in iPWRs. Areas where the current MELCOR severe accident modeling framework has limitations in the representation of phenomenological processes are identified and examples of possible modeling remedies are discussed. The paper identifies modeling and phenomenological issues that contribute to differences in the calculated reactor coolant system and containment response for iPWRs as compared to traditional PWRs under severe accident conditions.
SMR: Small Air Cooler and Air Filter Systems
Authors: Franklin Ben , Alvarez Julio R.
Published: February 2012

This paper is a presentation and discussion of generic descriptions of small air cooling units and small air filtration units to fit in and serve the small available volumes of space in the SMR (Small Modular Reactors).
On the Thermal-Hydraulic Essentials of the Holtec Inherently Safe Modular Underground Reactor (HI-SMUR) System
Authors: Singh Kris , Rampall Indresh , Rajkumar Joseph
Published: February 2012

HI-SMUR 140 is a small (145 MWe) modular pressurized water reactor designed to harness fission energy without the use of a recirculation pump. HI-SMUR’s core resides deep underground in a thick-walled reactor vessel (RV) enclosed by a stainless steel-lined reinforced concrete “Reactor Well”. The HI-SMUR Nuclear Steam Supply System (NSSS) is a conjugated pressure vessel assemblage wherein the steam generator(s) are integrally joined to the RV, i.e., without any interconnecting piping, and the pressurizer is integral to the reactor vessel. There are no penetrations in the RV for over a height of 120 feet above the reactor core, which precludes the scenario of loss of coolant to the core from a postulated pipe break event. The rejection of decay heat from the reactor in the wake of a scram is engineered to occur without the aid of on-site or off-site power, making the HI-SMUR NSSS demonstrably capable of withstanding a cataclysmic environmental phenomenon of Fukushima’s intensity without loss of core cooling or without precipitating any damage to the plant or the surrounding environment. The system design places a premium on accessibility and maintainability of vital equipment such as the steam generators, RV internals, and the control rod drive assemblies. This paper is the first in a series of papers planned to explain and quantify the performance and safety aspects of HI-SMUR 140. In this paper, the thermal-hydraulic characteristics of the HI-SMUR NSSS are explored using classical hydraulic correlations which have served as the tool for the scoping parametric study of the system. In particular, the stability of the system under varying power output conditions and the long-term reliability of the fuel under the most adverse thermal/hydraulic conditions are presented.
Aircraft Impact Considerations for NuScale SMR Plant Design
Authors: James Randy J. , Parker Josh , Hill Rick , Wiesner Jeremy , Groome John
Published: February 2012

All new nuclear power plants to be constructed and operated in the United States must meet regulatory requirements for aircraft impact from a large commercial aircraft under 10CFR50.150. Under the regulation, the applicant, using realistic analyses, must identify and incorporate into the design those design features and functional capabilities to show that, with reduced use of operator actions, 1) either the primary containment system remains intact or the reactor core remains cooled, and 2) either spent fuel cooling or spent fuel pool integrity is maintained. Small modular reactors have both advantages and disadvantages over conventional large plant designs in this regard. Small modular reactors generally have smaller footprints and can be configured where the reactor vessels and containment systems are entirely below grade. This minimizes the exposed structure that houses the reactors and spent fuel pool, which generally means that the structural configuration can be more efficiently hardened to resist the impact forces without excessive costs. However, the smaller footprint also means that transmission of shock through the structure can affect more safety equipment than in the larger conventional plant where the safety related equipment for the divisions are physically farther apart. Modular designs by nature tend to have all associated safety equipment together for each reactor module. Larger plants may be more tolerant for allowing internal damage and controlling ensuing fire due to perforation of aircraft wreckage at some strike locations, whereas the smaller footprints for small modular reactors could mean more systems are at risk if the reactor building is not hardened to prevent perforation. This paper presents design considerations employed for the NuScale 12 Module Power Plant in regards to aircraft impact requirements.
Meeting the Challenge
Authors: Town Nigel , Goldsworth Aidan , Lawler Steven
Published: February 2012

The market forecast for Small Reactor applications varies dependent upon the intelligence source used. It is nevertheless clear that the forecasted market volume presents a significantly different challenge to anything the nuclear industry has previously encountered. The industry response to this challenge could be evolutionary or revolutionary. Evolution could be considered the traditional, more relaxed approach as manufacturing capacity and validation techniques develop in-line with market growth & demand. However this approach would not deliver the level of manufacturing efficiencies required to support the Small Reactor programs. Industry must therefore take a revolutionary approach and look towards process optimization, with a focus on design for manufacture (DFM) and design for assembly (DFA). With manufacturing & assembly facilities tailored to meet this challenge, there is an opportunity to introduce new manufacturing philosophies such as ‘flowline’ manufacture — a hybrid between production line and batch processing techniques. Flowline manufacture is a product-oriented manufacturing technique which benefits from aspects of production line approach, e.g. standardized tasks, standardized tooling, and standardized processes. This approach offers an opportunity to validate & verify product parameters during the assembly stage, eliminate non-value added activities, and deliver a Small Reactor product to the required volume demand in a controlled, traceable, safe and reliable manner.
Residual Stress and Crack Mitigation for Dissimilar Metal Welded Nuclear Pipes
Authors: Yang Yu-Ping
Published: February 2012

Welding is a important manufacturing process in the fabrication of small modular reactors. However, welding often produces high residual stress in the weld or heat-affected-zone (HAZ). Many stress mitigation techniques were investigated in nuclear industry including weld overlay and mechanical stress improvement process (MSIP). The MSIP has been used to mitigate the residual stress in the pipe welding such as to control stress corrosion cracking (SCC) in dissimilar metal welded pipes. This paper optimizes this MSIP process with finite element analyses to achieve the maximum residual stress reduction. The effect of three parameters in MSIP, the clamp tool edge to the weld center (a), the clamp width in axial direction (b), and the applied pressure (p) on weld residual stress distributions were studied. A set of optimal process parameters for the dissimilar metal welded joint was predicted. In addition, the action of MSIP was further understood and demonstrated with numerical results and described in contour plots. The plots showed that both axial and hoop weld residual stress on more than half of the pipe wall thickness near the weld became compressive after applying MSIP, although they were highly tensile after welding. MSIP shifted the hoop tensile residual stress from the weld and heat-affected zone to the MSIP locations which are not sensitive to SCC.
Assessment of Small Modular Reactor Fuel Cost
Authors: Pannier Christopher , Sˇkoda Radek
Published: February 2012

Small Modular Reactors (SMRs) offer to the nuclear industry a simple, standardized, and safe option for new reactor builds as they are factory built, requiring smaller initial capital investment with shorter construction times. SMRs also promise competitive economy when compared with the current fleet. Construction cost estimates for a majority of the projects, which are mostly in their design stages, are proprietary, but fuel configuration, fuel enrichment, average burn-up, and thermal efficiency are publicly available for most SMR projects. This paper calculates the fuel cost when generating electricity, for selected SMR plants, including optimal tails depletion. The results are compared between one another and with current Light Water Reactors (LWR), providing a rough comparison of a long-term economics once the capital investment is amortized.
Numerical Analysis of Water-Based Nanofluid Coolant for Small Modular Reactor
Authors: Nazififard Mohammad , Nematollahi Mohammadreza , Suh Kune Y.
Published: February 2012

This paper is aimed at understanding thermohydrodynamic and neutronic characteristics of nanofluids for prospective application to water cooled small modular reactors. Numerical analysis is performed to investigate turbulent convective heat transfer and flow features of Al2O3 nanofluids as working fluid. The Al2O3-water nanofluids of 1%, 4% and 6% by volume have been employed for the numerical simulation resorting to the homogenous fluid assumptions with modified thermophysical properties. Results indicate that the heat transfer increases with nanoparticle volume concentrations by 4.2%–31% as compared against that for pure water. The maximum heat transfer increase at the center of a subchannel formed by fuel rods is 31.29% for the particle volume concentration of 6% corresponding to the Reynolds number of 65,000. It consequently appears promising enough to use nanofluids in small modular reactors. Neutronic and thermohydrodynamic investigations are further needed to streamline the nanoparticles and to optimize their concentration during the normal and abnormal operations.
Breast Cancer–Associated
Abraxas
Mutation Disrupts Nuclear Localization and DNA Damage Response Functions
Authors: Solyom Szilvia , Aressy Bernadette , Pylkäs Katri , Patterson-Fortin Jeffrey , Hartikainen Jaana M. , Kallioniemi Anne , Kauppila Saila , Nikkilä Jenni , Kosma Veli-Matti , Mannermaa Arto , Greenberg Roger A. , Winqvist Robert
Published: February 2012

A germline mutation in the
Abraxas
gene impairs BRCA1 DNA damage response function and is associated with familial breast cancer.
Inhibition of Bacterial Biofilm Formation and Swarming Motility by a Small Synthetic Cationic Peptide
Authors: de la Fuente-Núñez César , Korolik Victoria , Bains Manjeet , Nguyen Uyen , Breidenstein Elena B. M. , Horsman Shawn , Lewenza Shawn , Burrows Lori , Hancock Robert E. W.
Published: February 2012

Biofilms cause up to 80% of infections and are difficult to treat due to their substantial multidrug resistance compared to their planktonic counterparts. Based on the observation that human peptide LL-37 is able to block biofilm formation at concentrations below its MIC, we screened for small peptides with antibiofilm activity and identified novel synthetic cationic peptide 1037 of only 9 amino acids in length. Peptide 1037 had very weak antimicrobial activity, but at 1/30th the MIC the peptide was able to effectively prevent biofilm formation (>50% reduction in cell biomass) by the Gram-negative pathogens
Pseudomonas aeruginosa
and
Burkholderia cenocepacia
and Gram-positive
Listeria monocytogenes
. Using a flow cell system and a widefield fluorescence microscope, 1037 was shown to significantly reduce biofilm formation and lead to cell death in biofilms. Microarray and follow-up studies showed that, in
P. aeruginosa
, 1037 directly inhibited biofilms by reducing swimming and swarming motilities, stimulating twitching motility, and suppressing the expression of a variety of genes involved in biofilm formation (e.g., PA2204). Comparison of microarray data from cells treated with peptides LL-37 and 1037 enabled the identification of 11 common
P. aeruginosa
genes that have a role in biofilm formation and are proposed to represent functional targets of these peptides. Peptide 1037 shows promise as a potential therapeutic agent against chronic, recurrent biofilm infections caused by a variety of bacteria.
Comparative
In Vivo
Efficacies of Epithelial Lining Fluid Exposures of Tedizolid, Linezolid, and Vancomycin for Methicillin-Resistant Staphylococcus aureus in a Mouse Pneumonia Model
Authors: Tessier Pamela R. , Keel Rebecca A. , Hagihara Mao , Crandon Jared L. , Nicolau David P.
Published: February 2012

The antibacterial efficacies of tedizolid phosphate (TZD), linezolid, and vancomycin regimens simulating human exposures at the infection site against methicillin-resistant
Staphylococcus aureus
(MRSA) were compared in an
in vivo
mouse pneumonia model. Immunocompetent BALB/c mice were orally inoculated with one of three strains of MRSA and subsequently administered 20 mg/kg TZD every 24 hours (q24h), 120 mg/kg linezolid q12h, or 25 mg/kg vancomycin q12h over 24 h. These regimens produced epithelial lining fluid exposures comparable to human exposures observed following intravenous regimens of 200 mg TZD q24h, 600 mg linezolid q12h, and 1 g vancomycin q12h. The differences in CFU after 24 h of treatment were compared between control and treatment groups. Vehicle-dosed control groups increased in bacterial density an average of 1.1 logs. All treatments reduced the bacterial density at 24 h with an average of 1.2, 1.6, and 0.1 logs for TZD, linezolid, and vancomycin, respectively. The efficacy of TZD versus linezolid regimens against the three MRSA isolates was not statistically different (
P
> 0.05), although both treatments were significantly different from controls. In contrast, the vancomycin regimen was significantly different from TZD against one MRSA isolate and from linezolid against all isolates. The vancomycin regimen was less protective than either the TZD or linezolid regimens, with overall survival of 61.1% versus 94.7% or 89.5%, respectively. At human simulated exposures to epithelial lining fluid, vancomycin resulted in minimal reductions in bacterial counts and higher mortality compared to those of either TZD or linezolid. TZD and linezolid showed similar efficacies in this MRSA pneumonia model.
Novel
N
-Benzoyl-2-Hydroxybenzamide Disrupts Unique Parasite Secretory Pathway
Authors: Fomovska Alina , Huang Qingqing , El Bissati Kamal , Mui Ernest J. , Witola William H. , Cheng Gang , Zhou Ying , Sommerville Caroline , Roberts Craig W. , Bettis Sam , Prigge Sean T. , Afanador Gustavo A. , Hickman Mark R. , Lee Patty J. , Leed Susan E. , Auschwitz Jennifer M. , Pieroni Marco , Stec Jozef , Muench Stephen P. , Rice David W. , Kozikowski Alan P. , McLeod Rima
Published: February 2012

Toxoplasma gondii
is a protozoan parasite that can damage the human brain and eyes. There are no curative medicines. Herein, we describe our discovery of
N
-benzoyl-2-hydroxybenzamides as a class of compounds effective in the low nanomolar range against
T. gondii in vitro
and
in vivo
. Our lead compound, QQ-437, displays robust activity against the parasite and could be useful as a new scaffold for development of novel and improved inhibitors of
T. gondii
. Our genome-wide investigations reveal a specific mechanism of resistance to
N
-benzoyl-2-hydroxybenzamides mediated by adaptin-3β, a large protein from the secretory protein complex.
N
-Benzoyl-2-hydroxybenzamide-resistant clones have alterations of their secretory pathway, which traffics proteins to micronemes, rhoptries, dense granules, and acidocalcisomes/plant-like vacuole (PLVs).
N
-Benzoyl-2-hydroxybenzamide treatment also alters micronemes, rhoptries, the contents of dense granules, and, most markedly, acidocalcisomes/PLVs. Furthermore, QQ-437 is active against chloroquine-resistant
Plasmodium falciparum
. Our studies reveal a novel class of compounds that disrupts a unique secretory pathway of
T. gondii
, with the potential to be used as scaffolds in the search for improved compounds to treat the devastating diseases caused by apicomplexan parasites.
THE SPIN-1 BLUME–CAPEL MODEL WITH ALTERNATINGLY CHANGING BILINEAR EXCHANGE INTERACTIONS BETWEEN SUBLATTICES
Authors: ALBAYRAK ERHAN
Published: February 2012

The spin-1 Blume–Capel model is studied on a Bethe lattice which is divided into two sublattices A and B. Alternatingly changing bilinear exchange interactions, JAB and JBA, between the sublattices, i.e., between the nearest-neighbor shell spins, are assumed. The phase diagrams of the model are studied on the (JAB, T) planes for given values of JBA, crystal fields D and the coordination numbers q = 3, 4 and 6. It was found that the model either displays only second-order phase transition lines at higher crystal field values or second- and first-order phase transitions lines combined at tricritical points at lower negative crystal fields. It was also found that the tricritical points move to higher temperatures and to higher values of JAB as the crystal field becomes more negative.
THEORY OF SPACETIME ELASTICITY
Authors: GUSEV ANDREI A. , LURIE SERGEY A.
Published: February 2012

We present the theory of spacetime elasticity and demonstrate that it involves traditional thermoelasticity. Assuming linear-elastic constitutive behavior and using spacetime transversely-isotropic elastic constants, we derive all principal thermodynamic relations of classical thermoelasticity. We introduce the spacetime principle of virtual work, and use it to derive the equations of motion for both reversible and dissipative thermoelastic dynamics. We show that spacetime elasticity directly implies the Fourier and the Maxwell–Cattaneo laws of heat conduction. However, spacetime elasticity is richer than classical thermoelasticity, and it advocates its own equations of motion for coupled thermoelasticity, complemented by the spectrum of boundary and interface conditions. We argue that the presented framework of spacetime elasticity should prove adequate for describing the thermoelastic phenomena occurring at low temperatures, for interpreting the results of molecular simulations of heat conduction in solids, and also for the optimal heat and stress management in the microelectronic components and the thermoelectric devices.
SECRET IMAGE SHARING BASED ON CHAOTIC MAP AND CHINESE REMAINDER THEOREM
Authors: HU CHUNQIANG , LIAO XIAOFENG , XIAO DI
Published: February 2012

Secret sharing is an efficient method for transmitting the image securely. This paper proposes an efficient secret sharing scheme for secret image. The protocol allows each participant to share a secret gray image with the rest of participants. In our scheme, a secret digital image is divided into n pieces, which are further distributed into n participants. The secret digital image can be reconstructed if and only if r or more legal participants cooperate together. These schemes have no pixel expansion. It is general in nature and can be applied on any image size. The proposed scheme is based on the chaotic map and the Chinese Remainder theorem. The security of the scheme is analyzed and the protocol is proven to be secure and be able to resist statistic and exhaustive attacks.
DO INSTITUTIONS AND SOCIAL COHESION ENHANCE THE EFFECTIVENESS OF AID? NEW EVIDENCE FROM AFRICA
Authors: BALIAMOUNE-LUTZ MINA
Published: February 2012

This paper explores the effects of aid, institutions, and social cohesion on per capita income growth in 34 African countries using the Arellano-Bond dynamic panel GMM estimator. The paper focuses on the interplay of aid and institutions and the interplay of aid and social cohesion. The empirical results indicate that social cohesion enhances the growth effects of aid but there is a threshold effect, suggesting that aid becomes effective in enhancing growth in countries with higher social cohesion. Surprisingly, the results show that beyond a certain level of improvements in institutional quality, institutions (political rights and civil liberties) reduce the effectiveness of aid.