The role of the reactor size for an investment in the nuclear sector: an evaluation of not-financial parameters

The literature presents many studies about the economics of new Nuclear Power Plants (NPPs). Such studies are based on Discounted Cash Flow (DCF) methods encompassing the accounts related to Construction, Operation & Maintenance, Fuel and Decommissioning. However the investment evaluation of a nuclear reactor should also include not-financial factors such as siting and grid constraints, impact on the national industrial system, etc. The Integrated model for the Competitiveness Assessment of SMRs (INCAS), developed by Politecnico di Milano cooperating with the IAEA, is designed to analyze the choice of the better Nuclear Power Plant size as a multidimensional problem. In particular the INCAS’s module “External Factors” evaluates the impact of the factors that are not considered in the traditional DCF methods. This paper presents a list of these factors, providing, for each one, the rationale and the quantification procedure; then each factor is quantified for the Italian case. The IRIS reactor has been chosen as SMR representative. The approach and the framework of the model can be applied to worldwide countries while the specific results apply to most of the European countries. The results show that SMRs have better performances than LRs with respect to the external factors, in general and in the Italian scenario in particular

Clinical Features and Prognosis of HLA-B27 Positive and Negative Anterior Uveitis in a Korean Population

Clinical features and prognosis of HLA-B27 positive anterior uveitis (AU) were assessed compared with HLA-B27 negative AU in a Korean population, based on the medical records of AU patients seen at a university hospital. Twenty-seven HLA-B27 negative, idiopathic AU patients (group I) and 55 HLA-B27 positive AU patients (group II) were studied. HLA-B27 positive group was further divided into 29 with associated systemic disease (seronegative spondyloarthropathy) (group IIA) and 26 without associated systemic disease (group IIB). Significantly more severe anterior chamber inflammation in terms of anterior chamber cells (P=0.006) and hypopyon formation (P=0.034) was observed with higher frequency of AU attacks (P=0.007) in the HLA-B27 positive group than in the HLA-B27 negative group. Systemic/periocular steroids were required in significantly more patients in the HLA-B27 positive group than in the HLA-B27 negative group (P=0.015). However, no significant differences were observed for final ocular and visual outcomes between these two groups. Associated systemic disease made no significant difference in the clinical features and prognosis in the HLA-B27 positive AU patients. In conclusion, despite more severe inflammation and a higher recurrence rate, HLA-B27 positive AU shows similar good final ocular and visual outcomes compared to HLA-B27 negative, idiopathic AU in a Korean population

UPGRADE OF THE ARGONNE WAKEFIELD ACCELERATOR FACILITY (AWA): COMMISSIONING OF THE RF GUN AND LINAC STRUCTURES FOR DRIVE BEAM GENERATION*

Abstract Research at the AWA Facility has been focused on the development of electron beam driven wakefield structures. Accelerating gradients of up to 100 MV/m have been excited in dielectric loaded cylindrical structures operating in the microwave range of frequencies. Several upgrades, presently underway, will enable the facility to explore higher accelerating gradients, and also be able to generate longer RF pulses of higher intensity. The major items included in the upgrade are: (a) a new RF gun with a higher quantum efficiency photocathode will replace the RF gun that has been used to generate the drive bunches; (b) the existing RF gun will be used to generate a witness beam to probe the wakefields; (c) three new L-band RF power stations, each providing 25 MW, will be added to the facility; (d) five linac structures will be added to the drive beamline, bringing the beam energy up from 15 MeV to 75 MeV. The upgraded drive beam will consist of bunch trains of up to 32 bunches spaced by 0.77 ns with up to 100 nC per bunch. The goal of future experiments is to reach accelerating gradients of several hundred MV/m and to extract RF pulses with GW power level. AWA FACILITY The mission of the Argonne Wakefield Accelerator Facility (AWA) is to develop technology for future High Energy Physics accelerators. The facility has been used to study and develop new types of accelerating structures based on electron beam driven wakefields. In order to carry out these studies, the facility employs a photocathode RF gun capable of generating electron beams with high bunch charges and short bunch lengths. This high intensity beam is used to excite wakefields in the structures under investigation. The facility is also used to investigate the generation and propagation of high brightness electron beams, and to develop novel electron beam diagnostics. The AWA high intensity electron beam is generated by a photocathode RF gun, operating at 1.3 GHz. This oneand-a-half cell gun typically runs with 12 MW of input power, which generates an 80 MV/m electric field on its Magnesium photocathode surface. A 1.3 GHz linac structure increases the electron beam energy, from the 8 MeV produced by the RF gun, to 15 MeV. The linac is an iris loaded standing-wave structure operating in the π/2 mode with an average accelerating gradient of 7 MV/m; it has large diameter irises to minimize the undesirable wakefields generated by the passage of high charge electron bunches

Understanding emotionally relevant situations in primary dental practice. 3. Emerging narratives

Background and aims. Dentists experience considerable occupational stress. Stressful clinical situations can provoke high levels of negative emotions, and situations which are associated with positive emotions tend to be overlooked by practitioners. Reflection regarding difficult situations is encouraged to facilitate learning. Cognitive behavioural therapy (CBT) formulations may be applied to situations appraised both positively and negatively. Analysis and interpretation of the dentist's coping behaviour and the consequent outcomes facilitate learning and reflection upon individual interactions with patients. Method. Twenty primary care dental practitioners in the greater Lincoln area participated in a semi-structured interview which explored their stressful and positive clinical experiences. Some of the episodes were analysed to create CBT formulations. Results and discussion. CBT formulations are presented and the learning points highlighted by this structured presentation are discussed. In particular, it is suggested that this structured reconstruction of events, which highlights dentists' emotions, responses and the transactional effects of coping responses, might well facilitate objective reflective learning either individually or as part of peer to peer support. It should facilitate dentists' emotional processing of events and may thus contribute to stress reduction. Conclusion. CBT formulations of positive and negative dental scenarios may be constructed. It is proposed that this is a useful technique to foster reflection and learning in clinical situations and should lead to improved communication skills and shared decision-making, resulting in fewer complaints and thereby reduced stress. It should also improve dentists' emotional processing

Dynamical Boson Stars

The idea of stable, localized bundles of energy has strong appeal as a model for particles. In the 1950s John Wheeler envisioned such bundles as smooth configurations of electromagnetic energy that he called {\em geons}, but none were found. Instead, particle-like solutions were found in the late 1960s with the addition of a scalar field, and these were given the name {\em boson stars}. Since then, boson stars find use in a wide variety of models as sources of dark matter, as black hole mimickers, in simple models of binary systems, and as a tool in finding black holes in higher dimensions with only a single killing vector. We discuss important varieties of boson stars, their dynamic properties, and some of their uses, concentrating on recent efforts.Comment: 79 pages, 25 figures, invited review for Living Reviews in Relativity; major revision in 201

Core concepts for zero-sodium-void-worth core'' in metal fuelled fast reactor

Core design options to reduce the sodium void worth in metal fueled LMRs are investigated. Two core designs which achieve a zero sodium void worth are analyzed in detail. The first design is a pancaked'' and annular core with enhanced transuranic burning capabilities; the high leakage in this design yields a low breeding ratio and small void worth. The second design is an axially multilayered annular core which is fissile self-sufficient; in this design, the upper and lower core regions are neutronically decoupled for reduced void worth while fissile self-sufficiency is achieved using internal axial blankets plus external radial and axial blanket zones. The neutronic performance characteristics of these low void worth designs are assessed here; their passive safety properties are discussed in a companion paper. 16 refs., 2 figs., 3 tabs

ENSO Atmospheric Teleconnections and Their Response to Greenhouse Gas Forcing

This is the final version of the article. Available from AGU via the DOI in this record.El Niño and Southern Oscillation (ENSO) is the most prominent year-to-year climate fluctuation on Earth, alternating between anomalously warm (El Niño) and cold (La Niña) sea surface temperature (SST) conditions in the tropical Pacific. ENSO exerts its impacts on remote regions of the globe through atmospheric teleconnections, affecting extreme weather events worldwide. However, these teleconnections are inherently nonlinear and sensitive to ENSO SST anomaly patterns and amplitudes. In addition, teleconnections are modulated by variability in the oceanic and atmopsheric mean state outside the tropics and by land and sea ice extent. The character of ENSO as well as the ocean mean state have changed since the 1990s, which might be due to either natural variability or anthropogenic forcing, or their combined influences. This has resulted in changes in ENSO atmospheric teleconnections in terms of precipitation and temperature in various parts of the globe. In addition, changes in ENSO teleconnection patterns have affected their predictability and the statistics of extreme events. However, the short observational record does not allow us to clearly distinguish which changes are robust and which are not. Climate models suggest that ENSO teleconnections will change because the mean atmospheric circulation will change due to anthropogenic forcing in the 21st century, which is independent of whether ENSO properties change or not. However, future ENSO teleconnection changes do not currently show strong intermodel agreement from region to region, highlighting the importance of identifying factors that affect uncertainty in future model projections.S. W. Y. is supported by the KoreaMeteorological Administration Researchand Development Program under grant KMIPA2015-2112. Wenju Cai is supported by Earth System and Climate Change Hub of the Australia National Environmental Science Programme, and Centre for Southern Hemisphere Oceans Research, an international collaboration between CSIRO and Qingdao National Laboratory for Marine Sciences and Technology. B. Dewitte acknowledges supports from FONDECYT(1151185) and from LEFE-GMMC. Dietmar Dommenget is supported by ARC Centre of Excellence for Climate System Science (CE110001028)

Modeling causes of death: an integrated approach using CODEm

Background: Data on causes of death by age and sex are a critical input into health decision-making. Priority setting in public health should be informed not only by the current magnitude of health problems but by trends in them. However, cause of death data are often not available or are subject to substantial problems of comparability. We propose five general principles for cause of death model development, validation, and reporting.Methods: We detail a specific implementation of these principles that is embodied in an analytical tool - the Cause of Death Ensemble model (CODEm) - which explores a large variety of possible models to estimate trends in causes of death. Possible models are identified using a covariate selection algorithm that yields many plausible combinations of covariates, which are then run through four model classes. The model classes include mixed effects linear models and spatial-temporal Gaussian Process Regression models for cause fractions and death rates. All models for each cause of death are then assessed using out-of-sample predictive validity and combined into an ensemble with optimal out-of-sample predictive performance.Results: Ensemble models for cause of death estimation outperform any single component model in tests of root mean square error, frequency of predicting correct temporal trends, and achieving 95% coverage of the prediction interval. We present detailed results for CODEm applied to maternal mortality and summary results for several other causes of death, including cardiovascular disease and several cancers.Conclusions: CODEm produces better estimates of cause of death trends than previous methods and is less susceptible to bias in model specification. We demonstrate the utility of CODEm for the estimation of several major causes of death

A viral expression factor behaves as a prion

Prions are proteins that can fold into multiple conformations some of which are self-propagating. Such prion-forming proteins have been found in animal, plant, fungal and bacterial species, but have not yet been identified in viruses. Here we report that LEF-10, a baculovirus-encoded protein, behaves as a prion. Full-length LEF-10 or its candidate prion-forming domain (cPrD) can functionally replace the PrD of Sup35, a widely studied prion-forming protein from yeast, displaying a [PSI+]-like phenotype. Furthermore, we observe that high multiplicity of infection can induce the conversion of LEF-10 into an aggregated state in virus-infected cells, resulting in the inhibition of viral late gene expression. Our findings extend the knowledge of current prion proteins from cellular organisms to non-cellular life forms and provide evidence to support the hypothesis that prion-forming proteins are a widespread phenomenon in nature