Furnaces that are helping to keep our environment safe
Furnaces that are helping to keep our environment safe
Keywords: Environmental health and safety
Elite Thermal Systems Ltd, based in Market Harborough, Leicestershire, are continually setting the standards for electric ovens and furnaces. Always looking for new ways to service the market Elite have formed an alliance with Raddec Ltd, a Hampshire based scientific company, specialising in the extraction and measurement of radioactive elements such as tritium and carbon-14 for environmental and nuclear decommissioning projects.
Carbon-14 and tritium are produced naturally in the environment via cosmic ray bombardment in the upper atmosphere. They are also produced, more significantly, as by-products of nuclear power generation. The need to decommission ageing reactors and reactor buildings requires proper characterisation of diverse materials (e.g. metal, concrete, biota, soil,sediment, plastic, asbestos, and graphite) prior to any waste sentencing.
A number of different analytical techniques have been developed for the analysis of tritium and carbon-14 in the various materials. These include wet oxidation, which employs sulphuric acid, and persulphate oxidation systems for organically bound carbon-14, although most systems have limitations and draw backs.
Raddec's equipment is state-of-the- art and overcomes many of the previous limitations. The company set out to design a novel and integrated system that would have a long life, provide a high sample throughput and which would satisfy the demands of nuclear and environmental regulators, research and industry. Designed by scientists from the University of Southampton who specialise in environmental radioactivity and radiochemistry, the Raddec system represents a step forward in the nuclear power industry's abilities to accurately measure particular radionuclides.
At the core of the testing equipment is the Elite furnace. Specially designed by Raddec's scientists and built by Elite's engineers the furnace comes as a multi-tube system with integral controlled heating, metered air and oxygen flow,a catalytic zone and a bubbler chain to quantitatively trap the oxidised products. Four or six samples can be extracted at one time over a period as short as 3 h. Samples up to 10 g are placed in a silica boat and are transferred to their own silica-glass work-tube. Each of the work-tubes operate as a flow-through system where carrier gases of air and oxygen- enriched air move the volatile decomposition products from the sample zone through two other in-line,independently controlled furnace zones. The temperature of the sample-zone is ramped up to 500°C, or higher if needed, at an appropriate rate dependent on the sample type. The combustion products pass over a catalyst, held at 800°C,to ensure the complete oxidation of compounds containing tritium and carbon-14. The products are trapped in liquid bubblers and are measured using a liquid scintillation counter.
Raddec's specialised instruments are proving popular. NNC Ltd (NIRAS) that serves the nuclear industry has purchased five systems. Commenting on the Raddec system, Frank Pratley, Laboratory Manager at NNC-NIRAS, said “The Raddec furnaces are just what we need to efficiently assess the tritium content of waste and materials associated with nuclear decommissioning. The instruments are very well designed, function superbly and form an important part of our analytical armoury.”
Alf Roberts, Managing Director of Elite said, “At Elite the emphasis is on designing and producing leading edge quality products with excellent service delivery.” Alf continued, “We achieve our competitive advantage through collaboration with other leading edge companies and the collective experience of our design engineers who continually innovate new products.”
Elite boasts an impressive range of chamber, tube and custom built ovens and furnaces. The advanced material technology together with innovative design enables temperatures up to 2,000°C to be reached. With sophisticated software and data-logging capabilities, the ovens and furnaces can be supplied with multiple heating zones incorporating closed loop PID control.
