The Sellafield site, formerly known as Windscale and Calder Works, is a large nuclear plant sited in West Cumbria, in the North West of England. The Sellafield site is probably the most complex nuclear facility in the world, with safety systems to match. Many of the safety systems have been ‘back-fitted’ onto decades-old plant as safety cases have been modernised; however, due to the original design, many of these systems cannot be fully end-to-end proof tested. It is for this reason, Sellafield Ltd has developed their own risk-based process of how to assure the probability of failure on demand of a safety system when one or more of the components of the system cannot (throughout this paper where it is stated that the proof test ‘cannot be carried out’ it means it is undesirable for safety, practicality or business reasons) be fully or actively tested. Sellafield Ltd are leading the way in the proof testing of legacy plant throughout the nuclear and chemical industries in the United Kingdom; these arrangements, as described below, are considered (by Sellafield Ltd) as best practices for assuring the probability of failure on demand of Safety Instrumented System in legacy plants.
This paper presents a real-time hydrodynamic lubricant feeding conditions monitoring system for journal bearing in tandem cold mill to avoid online burning accident. A new kind of sensor connector has been developed to perform as a measuring section applied with nondestructive testing technology. The hydrodynamic lubricant feeding conditions in the tandem cold mill have been characterized. The monitoring results show that the hydrodynamic lubricant feeding conditions have been proved to be good indicators for the safety production. This real-time hydrodynamic lubricant feeding conditions monitoring system can be used as a long-term monitoring platform and provide an early warning for the tandem cold mill’s abnormal performance.
A pan-European project aimed at enhancing process efficiency through improved temperature measurement (EMPRESS) is described. The project is aimed at solving a suite of specific, documented problems in high-value manufacturing industry through improved temperature metrology for process control. A key aspect is the introduction of traceability to the International Temperature Scale of 1990 in process. This involves a concerted effort across Europe to improve existing sensing techniques such as thermocouples and fibre-optic based pyrometry, as well as introduction of completely new techniques including phosphor thermometry and combustion thermometry. Each activity in the project is characterised by the involvement of an end-user in industry, and there are opportunities for joining the Stakeholder Community associated with the project.
The measurement of the static position of rails in overhead industrial cranes is crucial to prevent failures and reduce undesired wearing effects due to wheels’ contact. The traditional procedure used to verify the rail alignment is based on manual operations, which can be overcome with the automatic methodology described in this paper. Through the design and building of a motorized trolley, the optical target point identifying the rail position is able to move automatically under remote wireless control. The measurement procedure is carried out considering one rail at a time and the data acquired on the two rails are then analyzed together by a specific software. Additional sensors embedded in the trolley allow to provide different parameters about the rail positioning and about the conditions of its surface. The system can be integrated in a laser tracking total station and can be controlled by the operator from the ground assuring a time reduction during installation and maintenance operations and greater safety for the operator.
Ultrasound transducers are used in a multitude of applications. A typical ultrasound transducer assembly consists of a piezoelectric layer, one or more matching layers and a backing layer. Dimensions and shape of these structural elements and properties of the used materials (especially those of piezoelectric layer) have a great influence on the resulting properties of the ultrasound transducer. The properties of the material used for the piezoelectric layer have strong dependence on the field conditions like temperature and pressure. The paper aims at studying the effect of temperature and pressure on the resonant frequency of the piezoelectric element. The change in the resonant frequency results in change in the material constants of the piezoelectric disc. Using these practical values of material constants, a realistic model of piezoelectric element can be developed. This helps in prediction of behaviour of the resulting ultrasound transducer and accelerates the design procedure. The real-life application considered for the conditions of temperature and pressure is open channel flow measurement. Traditionally used lead zirconate titanate (PZT)-based ceramic is the material chosen for the piezoelectric layer.