Radioactive Source Localisation via Projective Linear Reconstruction

Radiation mapping, through the detection of ionising gamma-ray emissions, is an important technique used across the nuclear industry to characterise environments over a range of length scales. In complex scenarios, the precise localisation and activity of radiological sources becomes difficult to determine due to the inability to directly image gamma photon emissions. This is a result of the potentially unknown number of sources combined with uncertainties associated with the source-detector separation—causing an apparent ‘blurring’ of the as-detected radiation field relative to the true distribution. Accurate delimitation of distinct sources is important for decommissioning, waste processing, and homeland security. Therefore, methods for estimating the precise, ‘true’ solution from radiation mapping measurements are required. Herein is presented a computational method of enhanced radiological source localisation from scanning survey measurements conducted with a robotic arm. The procedure uses an experimentally derived Detector Response Function (DRF) to perform a randomised-Kaczmarz deconvolution from robotically acquired radiation field measurements. The performance of the process is assessed on radiation maps obtained from a series of emulated waste processing scenarios. The results demonstrate a Projective Linear Reconstruction (PLR) algorithm can successfully locate a series of point sources to within 2 cm of the true locations, corresponding to resolution enhancements of between 5× and 10×

Best practice guidelines and lessons learned from robotic system deployment in nuclear decommissioning

The UK National Nuclear Laboratory (UK NNL) has a proven track record of delivering the deployment of robotic solutions for nuclear decommissioning at the Sellafield site with a description of the typical challenges faced and strategies being adopted outlined in [1]. This paper provides a high level overview of robotic deployment at the Sellafield site and provides an appreciation of the generic challenges and constraints commonly encountered during nuclear decommissioning. The findings from a review of a number of mid Technology Readiness Level (TRL) robotic projects undertaken by UK NNL are examined and lessons learned are identified to provide a common reference framework allowing success for future robotic projects to be optimised. TRLs represent a scale of technology readiness from 1 (blue sky research) to 9 (industrial application) established by the National Aeronautics and Space Administration (NASA). Mid-TRL stages are 4-6, including the development and testing at small to large scale, prior to ‘inactive commissioning’ (i.e., Stage 7) [2]. The aim is to identify common challenges to the deployment of robotic technologies for nuclear decommissioning in the UK. This approach will help to build an improved methodology and identify best practice guidelines for stakeholders; whilst assisting innovation in this area. This will help to accelerate decommissioning programmes and strategic objectives. This will also help to build stakeholder confidence in robotic solutions and help to convince end users to adopt these technologies to reduce overall project costs

Three dimensional characterization and archiving system

This system (3D-ICAS) is being developed as a remote system to perform rapid in situ analysis of hazardous organics and radionuclide contamination on structural materials. It is in the final phase of a 3-phase program to support Decontamination and Decommissioning (D&D) operations. Accurate physical characterization of surfaces and radioactive and organic contamination is a critical D&D task. Surface characterization includes identification of dangerous inorganic materials such as asbestos and transite. 3D-ICAS robotically conveys a multisensor probe near the surfaces to be inspected, using coherent laser radar tracking, which also provides 3D facility maps. High-speed automated organic analysis is provided by means of gas chromatograph-mass spectrometer sensor which can process a sample without contact in one minute. Volatile organics are extracted directly from contaminated surfaces without sample removal; multiple stage focusing is used for high time resolution. Additional discrimination is obtained through a final stage time-of-flight mass spectrometer. The radionuclide sensors combines {alpha}, {beta}, and {gamma} counting with energy discrimination of the {alpha} channel; this quantifies isotopes of U, Pu, Th, Tc, Np, and Am in one minute. The Molecular Vibrational Spectrometry sensor is used to characterize substrate material such as concrete, transite, wood, or asbestos; this can be used to provide estimates of the depth of contamination. The 3D-ICAS will be available for real-time monitoring immediately after each 1 to 2 minute sample period. After surface mapping, 3-D displays will be provided showing contours of detected contaminant concentrations. Permanent measurement and contaminant level archiving will be provided, assuring data integrity and allowing regulatory review before and after D&D operations

Environmental Management Technology Leveraging Initiative. Topical report, October 1, 1995--September 30, 1996

The ``Environmental Management Technology Leveraging Initiative,`` a cooperative agreement between the Global Environment and Technology Foundation and the Department of Energy-Morgantown Energy Technology Center, has completed its second year. This program, referred to as the Global Environmental Technology Enterprise (GETE) is an experiment to bring together the public and private sectors to identify, formulate, promote and refine methods to develop more cost-effective clean-up treatments. Working closely with Department of Energy officials, National Laboratory representatives, business people, academia, community groups, and other stakeholders, this program attempts to commercialize innovative, DOE-developed technologies. The methodology to do so incorporates three elements: business assistance, information, and outreach. A key advance this year was the development of a commercialization guidance document which can be used to diagnose the commercialization level and needs for innovative technologies

The proof of concept of a fused radiometric and optical stereoscopic imaging system

The proof of concept of a fused radiometric and optical stereoscopic imaging device is presented. The project was in collaboration with the National Nuclear Laboratory and the Nuclear Decommissioning Authority with the aim of developing a sensor that can be deployed in a nuclear decommissioning environment. The radiometric system was a Compton camera comprised of two HPGe planar detectors and presents a significant improvement in efficiency and dynamic range over coded aperture systems currently used in industry. The optical stereoscopic camera is the proprietary Bumblebee XB3 system that provides 3D physical information of the surroundings. Two main experiments are presented; the first investigated the disparity between true source location and reconstructed image position. This disparity was proven and methods for accounting for and correcting it were developed, whereby the image position accuracy was improved by a factor of 26.7. The second experiment imaged 20 MBq $^{137}$Cs sources at distances of 80 - 150 cm with both radiometric and optical stereoscopic systems simultaneously. The first fused images were produced using this data, with the radiometric sources and surroundings clearly visible. A GUI was developed in Matlab to process and fuse the data. Alongside both experiments image optimisation techniques were investigated. Pulse shape analysis was implemented and shown to improve image resolution by 30\% on average at the expense of efficiency. Fold 2 event imaging was conversely shown to improve efficiency at the expense of image resolution. This work provides the basis to develop the project towards a complete system. The steps that must be taken to realise this are outlined and recommendations for overcoming potential challenges are discussed

Are Autonomous Mobile Robots Able to Take Over Construction? A Review

Although construction has been known as a highly complex application field for autonomous robotic systems, recent advances in this field offer great hope for using robotic capabilities to develop automated construction. Today, space research agencies seek to build infrastructures without human intervention, and construction companies look to robots with the potential to improve construction quality, efficiency, and safety, not to mention flexibility in architectural design. However, unlike production robots used, for instance, in automotive industries, autonomous robots should be designed with special consideration for challenges such as the complexity of the cluttered and dynamic working space, human-robot interactions and inaccuracy in positioning due to the nature of mobile systems and the lack of affordable and precise self-positioning solutions. This paper briefly reviews state-ofthe-art research into automated construction by autonomous mobile robots. We address and classify the relevant studies in terms of applications, materials, and robotic systems. We also identify ongoing challenges and discuss about future robotic requirements for automated construction