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.

There was no existing technology capable of meeting the requirements of speed of measurement, accuracy, remote access and operations.

In a world first, Wood 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 analyse 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. The hydrogen release rate is calculated by summing the bubble volumes.

The system accounts for bubbles appearing, disappearing and merging, and will count bubbles on clear or cloudy liquors.

The system has progressed to Technology Readiness Level (TRL) 6 – full-scale inactive demonstration of an integrated system – and is expected to move to TRL 8/9 when it is deployed later this year.

Wood created a fit-for-purpose test rig, which enabled significant schedule and cost savings to be made during development.

The new system ensures that Sellafield Ltd can meet the waste characterisation requirements of the Office for Nuclear Regulation (ONR) in a way which takes only a minimal amount of time and costs very little.

The system has been trialled at full scale and is now being readied for deployment as part of the characterisation capability in two important Sellafield projects: Encapsulated Product Store-Waste Transfer Route and the Box Encapsulation Plant.

Contact
John Maddison, Wood
john.maddison@woodplc.com

Источник: eurosafe-forum 5.2019

Wood 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 the Sellafield nuclear site in the UK, Wood found a way to speed up the process and minimise 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 analysed 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 a great example of Wood’s ability to apply a mix of appropriate technologies to solve a difficult technical problem for customers in a cost-effective way.

Contact
Gordon John, Wood
gordon.john@woodplc.com

Источник: eurosafe-forum 5.2019