Radioactive Waste 758 - Viridian Develops The ViridiScope For Testing Irradiated Materials - Part 2 of 2 Parts

Radioactive Waste 758 - Viridian Develops The ViridiScope For Testing Irradiated Materials - Part 2 of 2 Parts

Part 2 of 2 Parts (Please read Part 1 first)
     Veridian collaborated with three site license companies that are supported by the Nuclear Decommissioning Authority (LLW Repository Ltd, Magnox Ltd, Sellafield Ltd) and EDF Energy Nuclear Generation Ltd. This collaboration gave the researchers access to five very different geological sites.
     John Williams is the director at Veridian who was charged with the design and construction of the operating systems for the ViridiScope. He said, “The pace of development was rapid, and the deployment on five nuclear sites in just nine months really tested the real-world operation and ruggedness of ViridiScope.”
     The sampling and characterization programs were set up to test functionality, speed of sample collection, robustness of equipment, the avoidance of contamination measures and the reliability of the ViridiScope in a real decommissioning site environment. Sampling took place during a three-month period. Teams collected a total of three hundred and fifty samples. The sample throughput rate was one sample processed every ten minutes.
   At Dragon, Winfrith, the ViridiScope was used to collect materials twenty-six feet up on a wall. Previously a scaffolding had to be erected to take samples at that height. Workers took over a hundred samples over a two hundred square foot area. Analysis of the samples demonstrated gamma activity for the following isotopes, Am-241, Cs-137 and Co-60. It took less than four hours to collect those samples. Some hotspots were sampled and the samples analyzed to prove that the activity detected was due to only Cs-137 radioactivity.
    At Drigg, two weeks were occupied in the collection of samples from walls and the floor. Detection limits of .1 Becquerels per gram were accomplished.
    Viridian worked as a subcontractor at Trawsfynydd. One of the main contractors’ engineers was trained by ViridiScope to take samples in two areas.
    The ViridiScope was used to take samples of a concrete core that had been drilled at Sellafield. The work took place at Socotec’s analytical laboratories. The use of the ViridiScope allowed the analysis to take place without sawing a sample off the core and grinding it up which is usually required by the current analytical system in use in the nuclear industry.
    The successful testing of ViridiScope at the five live sites, showed that the new technology worked well in difficult conditions such as high wind and low temperatures. The technology readiness level (TRL) for the VididScope was raised from seven to eight. The TRL is a type of measurement system that can be used to characterize the maturity level of a specific technology. Each evolving technology is checked against the parameters for each of the technology levels. It is then assigned an appropriate TRL rating appropriate to its progress.
    Much of the onsite work was intended to sample materials in “clear areas” with little radioactivity. The ViridiaScope had to be adapted to be able to report low level radioactivity at limits that were appropriate for the site and parameters of the test. The collection pods were modified to make them easier to open and to be acceptable to off-site analytical laboratories.
    Kym Jarvis is the managing director at Viridian. They have been working on the development of a smaller sampling head that would have the ability to be fired at a right angle in order to reach pipes, voids and other difficult to access areas. This work is being supported by the Innovative UK REACH project in collaboration with Createc and UKAEA RACE. This project is dedicated to the development of a combined, robotically-deployed sampling and gamma imaging sensor. Jarvis said, “The system will be trialed in April, showcasing this unique capability. ViridiScope now reaches places previously unimagined.”