Robust vulnerability analysis of nuclear facilities subject to external hazards     

Silvia?ToloEmail authorView author&#;s OrcID profile  Edoardo?Patelli  Michael?Beer 《Stochastic Environmental Research and Risk Assessment (SERRA)》2017,31(10):2733-2756

Natural hazards have the potential to trigger complex chains of events in technological installations leading to disastrous effects for the surrounding population and environment. The threat of climate change of worsening extreme weather events exacerbates the need for new models and novel methodologies able to capture the complexity of the natural-technological interaction in intuitive frameworks suitable for an interdisciplinary field such as that of risk analysis. This study proposes a novel approach for the quantification of risk exposure of nuclear facilities subject to extreme natural events. A Bayesian Network model, initially developed for the quantification of the risk of exposure from spent nuclear material stored in facilities subject to flooding hazards, is adapted and enhanced to include in the analysis the quantification of the uncertainty affecting the output due to the imprecision of data available and the aleatory nature of the variables involved. The model is applied to the analysis of the nuclear power station of Sizewell B in East Anglia (UK), through the use of a novel computational tool. The network proposed models the direct effect of extreme weather conditions on the facility along several time scenarios considering climate change predictions as well as the indirect effects of external hazards on the internal subsystems and the occurrence of human error. The main novelty of the study consists of the fully computational integration of Bayesian Networks with advanced Structural Reliability Methods, which allows to adequately represent both aleatory and epistemic aspects of the uncertainty affecting the input through the use of probabilistic models, intervals, imprecise random variables as well as probability bounds. The uncertainty affecting the output is quantified in order to attest the significance of the results and provide a complete and effective tool for risk-informed decision making.  相似文献   

Proposal of design rules for ductile X-CBFS in the framework of EUROCODE 8     

Silvia Costanzo  Mario D'Aniello  Raffaele Landolfo 《地震工程与结构动力学》2019,48(1):124-151

Cross concentrically braced frames (X-CBFs) are commonly used as primary seismic resisting system, owing to their large lateral stiffness, simplicity of design, and relatively low constructional cost. Current EN 1998-1 provides design rules theoretically aiming at developing ductile global plastic mechanism, namely enforcing plastic deformations in the diagonal members, while the remaining structural members and connections should elastically behave. However, as widely demonstrated by many existing studies, the design and the corresponding seismic performance of EC8-compliant X-CBFs are generally affected by several criticisms, eg, difficulties in sizing of diagonal members, massive and non-economical structures, and poor seismic behavior. In light of these considerations, the research activity presented in this paper is addressed to revise the design rules and requirements given EN 1998-1 for X-CBFs to simplify the design process and to improve the ductility and the dissipative capacity of this structural system. Hence, design rules are proposed for the next version of EN 1998-1 and numerically validated by means of nonlinear dynamic analyses.  相似文献   

Dissolved and particulate heavy metals distribution in coastal lagoons. A case study from Mar Chiquita Lagoon,Argentina     

María Ornela Beltrame  Silvia G. De Marco  Jorge E. Marcovecchio 《Estuarine, Coastal and Shelf Science》2009

Mar Chiquita Coastal Lagoon is located on the Atlantic coast of Argentina, and it has been declared a Biosphere Reserve under the UNESCO Man and Biosphere Programme (MAB). This coastal lagoon constitutes an estuarine environment with a very particular behaviour and it is ecologically important due to its biological diversity. The aim of the present study was to evaluate the distribution and geochemical behaviour of several heavy metals in this coastal system, focusing on their distribution in both the dissolved phase (<0.45 μm) and the suspended particulate matter. Therefore, the general hydrochemical parameters (salinity, temperature, turbidity, pH and dissolved oxygen) and concentration of total particulate and dissolved metals (Cd, Cu, Ni, Zn, Fe, Pb, Cr and Mn) were measured along 2 years (2004–2006) at two different sites. As regards their distribution, hydrological parameters did not present any evidence of deviation with respect to historical values. Suspended particulate matter showed no seasonal variation or any relationship with the tide, thus indicating that in this shallow coastal lagoon neither tides nor freshwater sources regulate the particulate matter input. Heavy metals behaviour, both in dissolved and particulate phases did not reveal any relationship with tide or seasons. Mar Chiquita Coastal Lagoon showed a large input of dissolved and particulate metals, which is probably due to intensive agriculture within the drainage basin of this system.  相似文献   

Vertical deformation partitioning across a collapsing large and hot orogen     

F. A. Temporim  Ricardo Ivan Ferreirae da Trindade  Marcos Egydio-Silva  Tiago Valim Angelo  Eric Tohver  Caroline Cibele Soares  Lucas Pequeno Gouvêa  Julio Cesar Mendes  Silvia Regina Medeiros  Antônio Carlos Pedrosa-Soares  Gabriel Gomes Silva 《地学学报》2023,35(1):23-31

Featuring 3 000-km-long large and hot orogen, the Mantiqueira Province provides a rare opportunity to study the process of gravitational collapse at mid to deep crustal levels. Distinct but contemporary (~500 Ma) post-collisional intrusions show structures and anisotropy of magnetic susceptibility (AMS) fabrics related to their emplacements, recording different flow patterns. In southern deep-seated intrusions, ellipsoidal-shaped roots with gabbroic-to-hybrid cores surrounded by granitic rocks show concentric patterns of AMS fabrics that cut across the NE-trending regional foliation. In contrast, northern intrusions, exposed as the upper sections of batholith-size bodies of coarse-grained granite emplaced at the shallow to mid-crust, show general NS-trending magnetic fabrics roughly parallel to strike of the orogen and the regional foliation of host rocks. These contrasting magnetic patterns from shallow to deeper crust suggest vertical magma migration from the overthickened orogenic core to be emplaced across its thinner stretched flanks during the gravitational collapse of the orogenic edifice.  相似文献