Sistema avanzado de alarmas para el reactor RA6.

Los sistemas de alarmas constituyen un elemento clave en las plantas modernas de procesos industriales. A lo largo de los años, los mismos han ido evolucionando de la mano del importante desarrollo en la industria del software, para pasar de ser simples paneles de anunciación y lámparas cableadas hasta complejos sistemas inteligentes que asisten al operador en sus funciones de operación. En el desarrollo de este trabajo se planteó diseñar un Sistema Avanzado de Alarmas para el Reactor Nuclear de Investigación RA6 contemplando las nuevas tecnologías existentes para incorporar mejoras a la actual sala de control. Para ello se trabajó siguiendo la metodología propuesta por la guía de diseño de sistemas de alarmas ANSI / ISA- SP-18. Para asistir al diseño y la verificación del sistema se utilizó un modelo termohidráulico de la planta desarrollado en Matlab/Simulink. Entre las nuevas herramientas incorporadas en el prototipo final obtenido se pueden mencionar: creación de archivos históricos, asignación de prioridades, supresiones de alarmas según estado operativo, filtrado y agrupamiento de alarmas.

Sistema avanzado de alarmas para el reactor RA6.

Los sistemas de alarmas constituyen un elemento clave en las plantas modernas de procesos industriales. A lo largo de los años, los mismos han ido evolucionando de la mano del importante desarrollo en la industria del software, para pasar de ser simples paneles de anunciación y lámparas cableadas hasta complejos sistemas inteligentes que asisten al operador en sus funciones de operación. En el desarrollo de este trabajo se planteó diseñar un Sistema Avanzado de Alarmas para el Reactor Nuclear de Investigación RA6 contemplando las nuevas tecnologías existentes para incorporar mejoras a la actual sala de control. Para ello se trabajó siguiendo la metodología propuesta por la guía de diseño de sistemas de alarmas ANSI / ISA- SP-18. Para asistir al diseño y la verificación del sistema se utilizó un modelo termohidráulico de la planta desarrollado en Matlab/Simulink. Entre las nuevas herramientas incorporadas en el prototipo final obtenido se pueden mencionar: creación de archivos históricos, asignación de prioridades, supresiones de alarmas según estado operativo, filtrado y agrupamiento de alarmas.

Assessing the impact of floods and flood legislation on residential property prices

The changing development and population sprawl in major cities, especially those located in high rainfall areas, has resulted in the need to review and re-assess potential flood impacts in these cities. In many cases these new flood lines and flood maps have placed residential property that was previously considered to be flood free to now be considered to be potentially flood liable. Previous research based in Sydney and the UK has identified the fact that residential property that has been subject to flooding has a decreased price and higher investment risk than flood free property in the same location. These studies have also shown that the greatest impact on residential property subject to flooding is just following a flood event. In June 2009, Brisbane City Council released revised flood maps for the Greater Brisbane region and these maps have identified areas that have not previously been considered flood liable. This paper will analyse the sale performance of flood liable streets in the main flood areas of Brisbane over the period January 1990 through to June 2009, to determine the variation in price for these flood liable areas to the residential property immediately adjoining them. The average sale price will be tracked on both a geographic location and socio-economic basis.

Flood fatalities in contemporary Australia (1997-2008) : disaster medicine

Objective: Flood is the most common natural disaster in Australia and causes more loss of life than any other disaster. This article describes the incidence and causes of deaths directly associated with floods in contemporary Australia. ---------- Methods: The present study compiled a database of flood fatalities in Australia in the period of 1997–2008 inclusive. The data were derived from newspapers and historic accounts, as well as government and scientific reports. Assembled data include the date and location of fatalities, age and gender of victims and the circumstances of the death. ---------- Results: At least 73 persons died as a direct result of floods in Australia in the period of 1997–2008. The largest number of fatalities occurred in New South Wales and Queensland. Most fatalities occurred during February, and among men (71.2%). People between the ages of 10 and 29 and those over 70 years are overrepresented among those drowned. There is no evident decline in the number of deaths over time. 48.5% fatalities related to motor vehicle use. 26.5% fatalities occurred as a result of inappropriate or high-risk behaviour during floods. ---------- Conclusion: In modern developed countries with adequate emergency response systems and extensive resources, deaths that occur in floods are almost all eminently preventable. Over 90% of the deaths are caused by attempts to ford flooded waterways or inappropriate situational conduct. Knowledge of the leading causes of flood fatalities should inform public awareness programmes and public safety police enforcement activities.

Assessment of pre- and post-flood groundwater recharge via 3D visualisation, Lockyer Valley, southeast Queensland

The Lockyer Valley in southeast Queensland supports important and intensive irrigation which is dependant on the quality and availability of groundwater. Prolonged drought conditions from ~1997 resulted in a depletion of the alluvial aquifers, and concern for the long-term sustainability of this resource. By 2008, many areas of the valley were at < 20% of storage. Some relief occurred with rain events in early 2009, then in December 2010 - January 2011, most of southeast Queensland experienced unprecedented flooding. These storm-based events have caused a shift in research focus from investigations of drought conditions and mitigation to flood response analysis. For the alluvial aquifer system of the valley, a preliminary assessment of groundwater observation bore data, prior to and during the flood, indicates that there is a spatially variable aquifer response. While water levels in some bores screened in unconfined shallow aquifers have recovered by more than 10 m within a short period of time (months), others show only a small or moderate response. Measurements of pre- and post-flood groundwater levels and high-resolution time-series records from data loggers are considered within the framework of a 3D geological model of the Lockyer Valley using Groundwater Visualisation System(GVS). Groundwater level fluctuations covering both drought and flood periods are used to estimate groundwater recharge using the water table fluctuation method (WTF), supplemented by estimates derived using chloride mass balance. The presentation of hydraulic and recharge information in a 3D format has considerable advantages over the traditional 2D presentation of data. The 3D approach allows the distillation of multiple types of information(topography, geological, hydraulic and spatial) into one representation that provides valuable insights into the major controls of groundwater flow and recharge. The influence of aquifer lithology on the spatial variability of groundwater recharge is also demonstrated.

Turbulent velocity and suspended sediment concentration measurements in an urban environment of the Brisbane River Flood Plain at Gardens Point on 12-13 January 2011

The flood flow in urbanised areas constitutes a major hazard to the population and infrastructure as seen during the summer 2010-2011 floods in Queensland (Australia). Flood flows in urban environments have been studied relatively recently, although no study considered the impact of turbulence in the flow. During the 12-13 January 2011 flood of the Brisbane River, some turbulence measurements were conducted in an inundated urban environment in Gardens Point Road next to Brisbane's central business district (CBD) at relatively high frequency (50 Hz). The properties of the sediment flood deposits were characterised and the acoustic Doppler velocimeter unit was calibrated to obtain both instantaneous velocity components and suspended sediment concentration in the same sampling volume with the same temporal resolution. While the flow motion in Gardens Point Road was subcritical, the water elevations and velocities fluctuated with a distinctive period between 50 and 80 s. The low frequency fluctuations were linked with some local topographic effects: i.e, some local choke induced by an upstream constriction between stairwells caused some slow oscillations with a period close to the natural sloshing period of the car park. The instantaneous velocity data were analysed using a triple decomposition, and the same triple decomposition was applied to the water depth, velocity flux, suspended sediment concentration and suspended sediment flux data. The velocity fluctuation data showed a large energy component in the slow fluctuation range. For the first two tests at z = 0.35 m, the turbulence data suggested some isotropy. At z = 0.083 m, on the other hand, the findings indicated some flow anisotropy. The suspended sediment concentration (SSC) data presented a general trend with increasing SSC for decreasing water depth. During a test (T4), some long -period oscillations were observed with a period about 18 minutes. The cause of these oscillations remains unknown to the authors. The last test (T5) took place in very shallow waters and high suspended sediment concentrations. It is suggested that the flow in the car park was disconnected from the main channel. Overall the flow conditions at the sampling sites corresponded to a specific momentum between 0.2 to 0.4 m2 which would be near the upper end of the scale for safe evacuation of individuals in flooded areas. But the authors do not believe the evacuation of individuals in Gardens Point Road would have been safe because of the intense water surges and flow turbulence. More generally any criterion for safe evacuation solely based upon the flow velocity, water depth or specific momentum cannot account for the hazards caused by the flow turbulence, water depth fluctuations and water surges.

Detection versus false alarm characterisation of a vision-based airborne dim-target collision detection system

This paper presents a preliminary flight test based detection range versus false alarm performance characterisation of a morphological-hidden Markov model filtering approach to vision-based airborne dim-target collision detection. On the basis of compelling in-flight collision scenario data, we calculate system operating characteristic (SOC) curves that concisely illustrate the detection range versus false alarm rate performance design trade-offs. These preliminary SOC curves provide a more complete dim-target detection performance description than previous studies (due to the experimental difficulties involved, previous studies have been limited to very short flight data sample sets and hence have not been able to quantify false alarm behaviour). The preliminary investigation here is based on data collected from 4 controlled collision encounters and supporting non-target flight data. This study suggests head-on detection ranges of approximately 2.22 km under blue sky background conditions (1.26 km in cluttered background conditions), whilst experiencing false alarms at a rate less than 1.7 false alarms/hour (ie. less than once every 36 minutes). Further data collection is currently in progress.