Understanding seismic design criteria for Japanese nuclear power plants

This paper summarizes the results of recent survey studies on the seismic design practice for nuclear power plants in Japan. The seismic design codes and standards for both nuclear as well as non-nuclear structures have been reviewed and summarized. Some key documents for understanding Japanese seismic design criteria are also listed with brief descriptions. The paper highlights the design criteria to determine the seismic demand and component capacity in comparison with US criteria, the background studies which have led to the current Japanese design criteria, and a survey of current research activities. More detailed technical descriptions are presented on the development of Japanese shear wall equations, design requirements for containment structures, and ductility requirements

Posttest Analyses of the Steel Containment Vessel Model

A high pressure test of a scale model of a steel containment vessel (SCV) was conducted on December 11-12, 1996 at Sandia National Laboratories, Albuquerque, NM, USA. The test model is a mixed-scaled model (1:10 in geometry and 1:4 in shell thickness) of an improved Mark II boiling water reactor (BWR) containment. This testis part of a program to investigate the response of representative models of nuclear containment structures to pressure loads beyond the design basis accident. The posttest analyses of this test focused on three areas where the pretest analysis effort did not adequately predict the model behavior during the test. These areas are the onset of global yielding, the strain concentrations around the equipment hatch and the strain concentrations that led to a small tear near a weld relief opening that was not modeled in the pretest analysis

Round Robin Analyses of the Steel Containment Vessel Model

A high pressure test of the steel containment vessel (SCV) model was conducted on December 11-12, 1996 at Sandia National Laboratories, Albuquerque, NM, USA. The test model is a mixed-scaled model (1:10 in geometry and 1:4 in shell thickness) of an improved Mark II boiling water reactor (BWR) containment. Several organizations from the US, Europe, and Asia were invited to participate in a Round Robin analysis to perform independent pretest predictions and posttest evaluations of the behavior of the SCV model during the high pressure test. Both pretest and posttest analysis results from all Round Robin participants were compared to the high pressure test data. This paper summarizes the Round Robin analysis activities and discusses the lessons learned from the collective effort

Steel Containment Vessel Model Test: Results and Evaluation

A high pressure test of the steel containment vessel (SCV) model was conducted on December 11-12, 1996 at Sandia National Laboratories, Albuquerque, NM, USA. The test model is a mixed-scaled model (1:10 in geometry and 1:4 in shell thickness) of an improved Mark II boiling water reactor (BWR) containment. A concentric steel contact structure (CS), installed over the SCV model and separated at a nominally uniform distance from it, provided a simplified representation of a reactor shield building in the actual plant. The SCV model and contact structure were instrumented with strain gages and displacement transducers to record the deformation behavior of the SCV model during the high pressure test. This paper summarizes the conduct and the results of the high pressure test and discusses the posttest metallurgical evaluation results on specimens removed from the SCV model

Intracellular changes in Ca2+, K+ and pH after sperm motility activation in the European eel (Anguilla anguilla): Preliminary results

[EN] Although it is widely accepted that osmolality and ion fluxes are the main factors triggering sperm motility in fish, a complex universal mechanism for sperm motility activation does not exist in fish, and studies of marine fish species are even more scarce. Therefore, the main goal of this study was to estimate the intracellular variations in the main ions involved in sperm activation for the first time in European eel, in order to provide additional new data about this little-known process. It was observed that levels of intracellular Ca2+ and K+ sperm ions increased significantly 30 s after the hyperosmotic shock compared to baseline levels, and remained at this level until 120 s post-activation. In contrast, the intracellular pH remained constant during the first 30 s, and decreased gradually at 60 and 120 s post-activation. Our data agree with the current main theory for explaining motility activation in marine fish, in which internal fluctuations of Ca2+ and K+ seem to participate in sperm activation. In addition, fluorescent images showed that both Ca2+ and K+ were concentrated in the apical area of the sperm head, which corresponds to the location of the eel sperm mitochondria, suggesting this organelle plays an important role in sperm motility activation. (C) 2013 Elsevier B.V. All rights reserved.Funded from the European Community's 7th Framework Programme under the Theme 2 "Food, Agriculture and Fisheries, and Biotechnology", grant agreement no 245257 (Pro-Eel) and the Spanish Ministry of Science and Innovation (MICINN; AGL2010-16009). Victor Gallego has a predoctoral grant (MICINN; BES-2009-020310) and has been granted a fellowship (EEBB-I-12-05858) of the Spanish Personnel Research Training Programme to carry out this study in the Universidad de Leon (Leon, Spain). Ilaria Mazzeo had a predoctoral grant from GVA. David S. Penaranda has a contract co-financed by MICINN and UPV (PTA2011-4948-I). F. Martinez-Pastor was supported by the Ramon y Cajal program (RYC-2008-02560, MICINN).Gallego Albiach, V.; Martínez Pastor, F.; Mazzeo, I.; Peñaranda, D.; Herraez, P.; Asturiano Nemesio, JF.; Pérez Igualada, LM. (2014). Intracellular changes in Ca2+, K+ and pH after sperm motility activation in the European eel (Anguilla anguilla): Preliminary results. Aquaculture. 418:155-158. https://doi.org/10.1016/j.aquaculture.2013.10.022S15515841

Climate resilience in marine protected areas and the ‘Protection Paradox’

Restricting human activities through Marine Protected Areas (MPAs) is assumed to create more resilient biological communities with a greater capacity to resist and recover following climate events. Here we review the evidence linking protection from local pressures (e.g., fishing and habitat destruction) with increased resilience. Despite strong theoretical underpinnings, studies have only rarely attributed resilience responses to the recovery of food webs and habitats, and increases in the diversity of communities and populations. When detected, resistance to ocean warming and recovery after extreme events in MPAs have small effect sizes against a backdrop of natural variability. By contrast, large die-offs are well described from MPAs following climate stress events. This may be in part because protection from one set of pressures or drivers (such as fishing) can select for species that are highly sensitive to others (such as warming), creating a ‘Protection Paradox’. Given that climate change is overwhelming the resilience capacity of marine ecosystems, the only primary solution is to reduce carbon emissions. High-quality monitoring data in both space and time can also identify emergent resilience signals that do exist, in combination with adequate reference data to quantify the initial system state. This knowledge will allow networks of diverse protected areas to incorporate spatial refugia against climate change, and identify resilient biological components of natural systems. Sufficient spatial replication further offers insurance against losses in any given MPA, and the possibility for many weak signals of resilience to accumulate

High level seismic/vibrational tests at the HDR: An overview

As part of the Phase II testing at the HDR Test Facility in Kahl/Main, FRG, two series of high-level seismic/vibrational experiments were performed. In the first of these (SHAG) a coast-down shaker, mounted on the reactor operating floor and capable of generating 1000 tonnes of force, was used to investigate full-scale structural response, soil-structure interaction (SSI), and piping/equipment response at load levels equivalent to those of a design basis earthquake. The HDR soil/structure system was tested to incipient failure exhibiting highly nonlinear response. In the load transmission from structure to piping/equipment significant response amplifications and shifts to higher frequencies occurred. The performance of various pipe support configurations was evaluated. This latter effort was continued in the second series of tests (SHAM), in which an in-plant piping system was investigated at simulated seismic loads (generated by two servo-hydraulic actuators each capable of generating 40 tonnes of force), that exceeded design levels manifold and resulted in considerable pipe plastification and failure of some supports (snubbers). The evaluation of six different support configurations demonstrated that proper system design (for a given spectrum) rather than number of supports or system stiffness is essential to limiting pipe stresses. Pipe strains at loads exceeding the design level eightfold were still tolerable, indicating that pipe failure even under extreme seismic loads is unlikely inspite of multiple support failures. Conservatively, an excess capacity (margin) of at least four was estimated for the piping system, and the pipe damping was found to be 4%. Comparisons of linear and nonlinear computational results with measurements showed that analytical predictions have wide scatter and do not necessarily yield conservative responses, underpredicting, in particular, peak support forces

Empleo del balón de contrapulsación intraaórtico como puente al trasplante cardiaco en España: resultados del estudio ASIS-TC

Introducción y objetivos En España, el balón de contrapulsación intraaórtico (BCIA) se ha usado frecuentemente como puente al trasplante cardiaco (TxC) urgente. El propósito es analizar los resultados de esta estrategia. Métodos Se realizó una revisión retrospectiva caso por caso de los registros clínicos de 281 pacientes adultos listados para TxC urgente asistidos con BCIA en 16 hospitales españoles entre 2010 y 2015. Se analizaron la supervivencia antes y después del trasplante y la incidencia de eventos adversos. Resultados Se trasplantó a 194 pacientes (69%; IC95%, 63, 3-74, 4) y 20 (7, 1%; IC95%, 4, 4-10, 8) fallecieron durante la asistencia, cuya duración media fue de 10, 9 ± 9, 7 días. El BCIA se explantó antes de obtener un órgano a 32 pacientes (11, 4%). En 35 pacientes (12, 5%; IC95%, 8, 8-16, 9) se implantó un dispositivo de asistencia circulatoria mecánica completa. El tiempo en la lista de espera urgente se incrementó desde 5, 9 ± 6, 3 días en 2010 hasta 15 ± 11, 7 días en 2015 (p = 0, 001). La supervivencia a 30 días y a 1 y 5 años tras el TxC fue del 88, 1% (IC95%, 85, 7-90, 5), 76% (IC95%, 72, 9-79, 1) y 67, 8% (IC95%, 63, 7-71, 9) respectivamente. La tasa de incidencia de eventos adversos mayores —disfunción del BCIA, ictus, hemorragia o infección— durante la asistencia fue de 26 (IC95%, 20, 6-32, 4) eventos/1.000 pacientes-día. La tasa de incidencia de explante del BCIA por complicaciones fue de 7, 2 (IC95%, 4, 5-10, 8) casos/1.000 pacientes-día. Conclusiones En el contexto de listas de espera cortas, el BCIA puede utilizarse como puente al TxC urgente con resultados aceptables. Esta estrategia conlleva una incidencia significativa de eventos adversos. Introduction and objectives: In Spain, intra-aortic balloon pump (IABP) has been used frequently as a bridge to urgent heart transplant (HT). We sought to analyze the clinical outcomes of this strategy. Methods: We conducted a case-by-case, retrospective review of clinical records of 281 adult patients listed for urgent HT under IABP support in 16 Spanish institutions from 2010 to 2015. Pre- and post-transplant survival and adverse clinical events were analyzed. Results: A total of 194 (69%, 95%CI, 63.3-74.4) patients were transplanted and 20 (7.1%, 95%CI, 4.4-10.8) died during a mean period of IABP support of 10.9 ± 9.7 days. IABP support was withdrawn before an organ became available in 32 (11.4%) patients. Thirty-five (12.5%, 95%CI, 8.8-16.9) patients transitioned from IABP to full-support mechanical devices. Mean urgent waiting list time increased from 5.9 ± 6.3 days in 2010 to 15 ± 11.7 days in 2015 (P =.001). Post-transplant survival rates at 30-days, 1-year, and 5-years were 88.1% (95%CI, 85.7-90.5), 76% (95%CI, 72.9-79.1), and 67.8% (95%CI, 63.7-71.9), respectively. The incidence rate of major adverse clinical outcomes—device dysfunction, stroke, bleeding or infection—during IABP support was 26 (95%CI, 20.6-32.4) episodes per 1000 patient-days. The incidence rate of IABP explantation due to complications was 7.2 (95%CI, 4.5-10.8) cases per 1000 patient-days. Conclusions: In a setting of short waiting list times, IABP can be used to bridge candidates to urgent HT with acceptable postoperative results, but there were significant rates of adverse clinical events during support. Full English text available from:www.revespcardiol.org/e

Complicaciones infecciosas relacionadas con la asistencia circulatoria mecánica de corta duración en candidatos a trasplante cardiaco urgente

Introducción y objetivos El uso de dispositivos de asistencia circulatoria mecánica de corta duración como puente a trasplante es frecuente en España. Se desconocen la epidemiología y la repercusión de las complicaciones infecciosas en estos pacientes. Métodos Descripción sistemática de la epidemiología y análisis de la repercusión pronóstica de las complicaciones infecciosas en un registro multicéntrico retrospectivo de pacientes tratados con dispositivos de asistencia circulatoria mecánica de corta duración como puente a trasplante cardiaco urgente entre 2010 y 2015 en 16 hospitales españoles. Resultados Se estudió a 249 pacientes; 87 (34, 9%) de ellos tuvieron un total de 102 infecciones. La vía respiratoria fue la localización más frecuente (n = 47; 46, 1%). En 78 casos (76, 5%) se obtuvo confirmación microbiológica; se aislaron en total 100 gérmenes causales, con predominio de bacterias gramnegativas (n = 58, 58%). Los pacientes con complicaciones infecciosas presentaron mayor mortalidad durante el periodo de asistencia circulatoria mecánica (el 25, 3 frente al 12, 3%; p = 0, 009) y menor probabilidad de recibir un trasplante (el 73, 6 frente al 85, 2%; p = 0, 025) que los pacientes sin infección. La mortalidad posoperatoria tras el trasplante fue similar en ambos grupos (con infección, el 28, 3%; sin infección, el 23, 4%; p = 0, 471). Conclusiones Los pacientes tratados con dispositivos de asistencia circulatoria mecánica de corta duración como puente al trasplante cardiaco están expuestos a un alto riesgo de complicaciones infecciosas, las cuales se asocian con una mayor mortalidad en espera del órgano. Introduction and objectives Short-term mechanical circulatory support is frequently used as a bridge to heart transplant in Spain. The epidemiology and prognostic impact of infectious complications in these patients are unknown. Methods Systematic description of the epidemiology of infectious complications and analysis of their prognostic impact in a multicenter, retrospective registry of patients treated with short-term mechanical devices as a bridge to urgent heart transplant from 2010 to 2015 in 16 Spanish hospitals. Results We studied 249 patients, of which 87 (34.9%) had a total of 102 infections. The most frequent site was the respiratory tract (n = 47; 46.1%). Microbiological confirmation was obtained in 78 (76.5%) episodes, with a total of 100 causative agents, showing a predominance of gram-negative bacteria (n = 58, 58%). Compared with patients without infection, those with infectious complications showed higher mortality during the support period (25.3% vs 12.3%, P = .009) and a lower probability of receiving a transplant (73.6% vs 85.2%, P = .025). In-hospital posttransplant mortality was similar in the 2 groups (with infection: 28.3%; without infection: 23.4%; P = .471). Conclusions Patients supported with temporary devices as a bridge to heart transplant are exposed to a high risk of infectious complications, which are associated with higher mortality during the organ waiting period