GLOBAL NUCLEAR |


Safer and more timely radiation monitoring Jacobs is making radiation monitoring of storage ponds safer and more timely by using specially adapted remotely operated vehicles (ROVs). Conventionally, samples of pond water are collected manually and sent away for


laboratory analysis. This approach exposes workers to increased radiation doses, carries the risk of contamination spread due to dropped samples and never gives a current reading because it takes several days to obtain the analysis results. In an innovative project at Sellafield, Jacobs found a way to speed up the process and minimize human intervention, while still obtaining the highest quality results. A submersible ROV collects samples of water before docking at a custom-built


monitoring station floating at the side of the pond, where the sample is analyzed by a gamma radiation spectrometer. With the new system, the reading is obtained in real time and there is no risk of contamination spread because the sample remains underwater. Sampling and monitoring is performed remotely meaning that the operator is not exposed to elevated radiation levels. This project is an example of how Jacobs can apply a mix of appropriate


technologies to solve a difficult technical problem for clients in a cost-effective way. ■


Above: A submersible ROV designed for radiation monitoring


Nowadays, many engineering projects such as designing an oil platform or a chemical plant are more of a logistical exercise than an engineering challenge because the engineering has all been done before. But Sellafield is not like that. David says: “Sellafield has accumulated a great deal of


knowledge and skills in tackling some of the world’s most complex nuclear decommissioning challenges. This means it has the potential to once again become a major contributor to the U.K.’s exports and GDP. “To be in a position to do that, we need to create a


collaborative, high-performing environment, minimize unproductive, avoidable activities and begin a virtuous cycle to embed engineering excellence. “This will enable us to deliver cost and schedule savings,


make projects less complicated and complete them sooner. “We have already energized our project engineering


managers with a set of new action plans and their response has been every bit as good as I hoped. They want to have a strong voice in the drive to make Sellafield safer sooner and because this is being driven from within, it is already generating its own momentum.” ■


To learn more: richard.howells@jacobs.com | 27


Bubbles are key to staying safe Waste retrieved from the Magnox Swarf Storage Silo (MSSS) at Sellafield is being safely stored in an unencapsulated form for 50-75 years. This has never been done before and it is safety critical that hydrogen generation is measured and managed, especially when the waste first goes into store. Sellafield Ltd made a commitment to the U.K. regulator to carry out prompt and accurate characterization of waste at all times but had to find a non-intrusive and cost-effective way of doing it. There was no existing technology capable of meeting the requirements of speed of


measurement, accuracy, remote access and operations. In a world first, Jacobs developed a non-invasive, remote measurement technique


to autonomously identify surface bubbles and provide volumetric assessment of hydrogen release rate in a matter of minutes. The novel system uses machine vision to analyze video of the liquor surface in the skip. A bespoke software program reads camera images and uses light patterns to identify and track bubbles on the surface and to measure their size. Hydrogen release rate is calculated by summing the bubble volumes. The new system ensures that Sellafield Ltd can meet the waste characterization


requirements of the Office for Nuclear Regulation (ONR) in a way which takes only a minimal amount of time and costs very little. ■


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