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One very important capability that is critical to the nuclear industry is the ability to determine the constituents and the radioactivity of samples of a wide variety of types of materials. The ViridiScope is a new laser sampling tool that was developed to improve the characterization of materials in nuclear applications. It can replace mechanical drilling to remove materials from a surface so that they can be analyzed. Concrete, plastic, wood, plaster and brick can be quickly sampled and analyzed for the presence of a large variety of radionuclides and for the characterization of the other atomic elements in the sample. The new sampling device was developed by the Veridian Consultants in the U.K. during a collaboration with Sellafield that started in 2013.
The ViridiScope utilizes a laser to quickly remove up to a one hundred milligram sample from a surface. The operation takes around three minutes. The sample is then moved away from the sampling site through a sixty-foot line to a collection pod. In the pod, the sample is analyzed for alpha, beta and gamma emissions or further processed in order to characterize radionuclides and stable elements that are present.
The ViridiScope has been tested at five nuclear sites including a low level waste repository at Drigg, the Socotec analytical laboratory, an experimental Dragon reactor at Winfirth, a reactor being decommissioned at Trawsfynydd and an operational nuclear power plant at Hinkley Point. The five sites were selected to allow a broad test of different application of the ViridiScope including manual and remote sampling for alpha, beta and gamma activity determination, low level radioactivity detection, and analysis of hotspots with high radioactivity on floors, walls and ceilings.
Before it was deployed, the performance characteristics of ViridiScope for sampling concrete were tested. Concrete is commonly found around nuclear sites. It was assumed that the ViridiScope could also be used on a wide variety of materials including steel and graphite which are also common on nuclear sites.
Manual and remote operation of the ViridiScope was demonstrated in non-active areas of the Imperial College Consort Reactor at Berkshire, Sellafield in Cumbria, Amec Foster Wheeler and in an active field test at Sellafield.
ViridiScope was tested at an actual decommissioning site in November of 2016. For this test, ViridiScope was compared to drilling, taking swabs and scraping the surface being sampled. The ViridiScope allowed the researchers to make a preliminary assessment of radiation contamination issues, robustness of the equipment and ease of use. During testing with and without radioactivity being present, the potential customers gave important feedback to help improve the design and functionality of the device.
One big problem with introducing new equipment into the nuclear industry is that there is serious resistance to change. A great deal of effort had to be expended to overcome this change resistance and pave the way for acceptance of the new tool. Field tests were carried out in order to show potential customers that the tool was able to function properly in real-world situations with performance that was needed for a great variety of application areas.
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