Research Area: |
Waste and Fuel Management |
|---|---|
PI: |
Prof. Tom Scott |
Partners: |
TWI, ImiTec Ltd., National Centre for Nuclear Robotics |
Contact details: |
t.b.scott@bristol.ac.uk |
The Challenge
The 2013 UK Radioactive Waste Management reports highlighted that the total volume of UK radioactive waste across NDA sites was ~165,000m3. The volume of future waste was forecast to be 4,330,000m3. Over 60% of the total waste volume is expected to be Very Low Level Waste (VLLW), with a further 30% classified as Low Level Waste (LLW). Intermediate Level Waste (ILW) will represent about 10% of the total packaged volume, with the proportion of classified High Level Waste (HLW) expected to be 0.03% [[i]]. Estimated waste disposal costs for LLW and is £2.9k/m3, compared with £46k/m3 for ILW [[ii]]. This includes costs for waste retrieval, conditioning, packaging and storage.
Large volume LLW and ILW consist of solid metallic waste streams, such as storage containers, pressure vessels, dissolvers and pipes. Most often the contaminated area is highly localised, but often the whole structure is classified according its peak activity. This means increased efforts in technology deployment, dismantling and/or size reduction, retrieval, decontamination, conditioning, packaging and disposal activities. This potentially leads to an increased risk of dose rate to operators and subsequently adds to the overall cost of decommissioning.
The INTEGRAL project, led by Imitec Ltd. in partnership with TWI and the University of Bristol, has addressed these needs by developing and demonstrating a novel technology, which combines laser cutting with accurate structure and radiation mapping of contaminated structures. Information collected on the distribution of radioactive contamination will facilitate waste re-classification and, through the selective cutting out of regions of higher activity, allows splitting of wastes into appropriate waste streams, thereby minimising legacy storage costs.
The approach is closely aligned with the Nuclear Decommissioning Authority's (NDA) strategy plan for decommissioning and integrated waste management, and will provide significant cost savings.
The Solution
The aim of project INTEGRAL, funded as part of the Innovate UK Energy Game Changers scheme, was to develop a device head, integrated onto a robot arm or similar platform, capable of scanning nuclear waste containers, to create a 3D model of the container and produce an overlaid radiation intensity map which subsequently forms the basis for a laser cutting pattern to allow separation parts of the structure which qualify as low and intermediate level radioactive wastes. Laser cutting also facilitates volume reduction of the waste form.
There are several key concepts that must be employed in order to achieve this. Firstly, a sensor capable of accurately measuring distance will be required for making a 3D profile of the drum. Secondly an appropriate gamma spectroscopy technique capable of accurately locating radiation hotspots on the container surface will be needed to construct a radiation intensity map. Thirdly a suitable laser cutting device, able to cut through multi millimetre thicknesses of stainless steel and finally, a robotic device is needed, possibly with an integrated platform able to rotate and navigate the surface of the container.
The INTEGRAL project, led by Imitec Ltd. in partnership with TWI and the University of Bristol, has addressed these needs by developing and demonstrating a novel technology, which combines laser cutting with accurate structure and radiation mapping of contaminated structures. Information collected on the distribution of radioactive contamination will facilitate waste re-classification and, through the selective cutting out of regions of higher activity, allows splitting of wastes into appropriate waste streams, thereby minimising legacy storage costs.
The approach is closely aligned with the Nuclear Decommissioning Authority's (NDA) strategy plan for decommissioning and integrated waste management, and will provide significant cost savings.
Addressing the UK's nuclear legacy is the largest, most important environmental remediation programme in Europe, with estimated expenditure of £115 billion over the next 120 years. A significant proportion of this cost is associated with decommissioning and management of high level radioactive waste. Therefore there is a need for remotely operated, waste characterisation, size reduction and decontamination technologies.
The Impact
Project INTEGRAL successfully demonstrated technology development which the industry has demanded. It makes the best of integrating two award-winning technologies from ImiTec and the TWI to create a prototype system for scanning and cutting down nuclear waste containers and separating the component pieces on the basis of their differing radioactivity.
It was also a successful University collaboration with local business: regional SME ImiTec worked with the TWI and was supported by the University of Bristol to deliver a game-changing technology for the nuclear industry.
The INTEGRAL demonstration has made use of our excellent new robotics capability at our Fenswood Research Facility which is now being developed both with physical resources and research students to build up the capability.