Sonic Boom: using sonar technology to help build a picture of inaccessible areas at Sellafield

Thanks to the seeds sown through a Nuclear Decommissioning Authority research and development grant, a Cumbrian SME is taking things to the next level both at Sellafield and abroad.

Earning a nickname based on your profession is nothing new. Bob the Builder and Postman Pat were the natural culmination of centuries of people being named after their jobs. But somewhere in the past we lost the link between what you’re called and what you do, meaning there’s now plenty of Masons who can’t lay a brick and Bakers unable to make a loaf.

That’s why it’s refreshing to meet Sonar Steve, also know as Steve Lainson, Managing Director of Fortis Remote Technology. He’s one of the few people on the Sellafield site to have the distinction of being named after what he does. It is a nickname that has been earned over the years through his work in using sonar scans to map the contents of settling tanks and hazardous areas such as the withdrawal and decanner bays in the Pile Fuel Storage Pond.

Now Steve has taken his sonar skills to a whole new level – both here and abroad. He has just completed his most challenging job yet at Sellafield, mapping one of the most congested legacy areas of the First Generation Magnox Storage Pond: the magazine transfer bay. It became cluttered over the facility’s operational years with blocked or faulty fuel magazines which were suspended above the floor. The tangle of material meant the area became inaccessible by remotely operated vehicles, so the only way of seeing what was inside before Steve came along was by peering in from above with torches.

“It is literally like chasing shadows,” said Steve. “Each time the sonar picks up something solid it means there’s a blind spot or ‘shadow’ behind that point which we have to map from a different angle. There was so much material in there that it took more than three times the normal number of sonar scans to survey the area. Add in the challenge of working in an area where access is restricted by radiation levels and it was the hardest job we’ve ever done,” said Steve. Considering other Fortis jobs could be looking for faults in an oil rig deep under the North Sea or scanning an icy cold underwater reservoir in North Wales, that’s some accolade.

The company has built up an international business from its rural base in Broughton, Cumbria. In 2007 Fortis successfully applied for a £32,000 research and development grant from the Nuclear Decommissioning Authority to use variable frequency sonar equipment to help characterise sludge in nuclear facilities. That grant allowed the company to build on the capability and intelligence offered by the more basic sonar equipment it had been using before. The seed sown by the research and development grant has not only brought benefits to the UK nuclear industry, it is also helping abroad. Fortis is now working alongside Cockermouth-based Createc on mapping reactors 1 and 2 at Fukushima. It is currently carrying out feasibility studies and modelling work before conducting the actual surveys at the Japanese facility, hopefully later this year.

“Working with our technology partners Createc and Marine Electronics we’re taking sonar technology to new places for nuclear applications,” said Steve. “We are currently developing sonar mapping so that it will not only tell us that there’s something there, it will also tell us what it’s made of. Our next generation sonar probes will be able to ‘feel’ the environment so they can tell the difference between, for example, sludge or concrete or steel. For nuclear applications the sonar data will be overlaid with the gamma radiation value of the target area too.”

All in all it’s a clear case of sonar, so far.

Joystick generation aids nuclear clean-up

The information captured in the sonar mapping of the magazine transfer bay in the First Generation Magnox Storage Pond is being used in new ways, thanks to technology pioneered in the gaming world. To fully explore the 3D map created by the sonar probes, those responsible for cleaning up the legacy pond will be putting on virtual reality headsets to have a really good look around. The basic virtual reality equipment is now available off the shelf for about £1000 and our robotics and autonomous systems expert Dr Paul Mort says the nuclear industry is now enjoying the benefits of products created for the multi-billion pound gaming sector:

“Twenty years ago we looked at buying laser capture systems similar to the ones you now put on top of the console or television to play certain games. They cost around £25,000, now you can get far more powerful and sophisticated versions for your home for around £80. The mass market is having massive benefits for us. Most families have teenagers using joypads to interact with 3D games. This development has helped us ‘humanise’ information and processes which could be really dry and boring if presented in just words or diagrams. It helps us get more value out of our data,” said Dr Mort.

He says affordable, off-the-shelf gaming technology could also help the nuclear industry open its doors to more small to medium sized enterprises. “If we can use this technology to illustrate an area which needs to be cleaned up, then it could remove the need to walk around the facility to scope out a job. That means new people with new ideas could start to help us. More precise information and modelling on the nature of the challenge could also help remove a lot of the uncertainty, meaning we’d have more accurate and realistic estimations of what the work is likely to cost. This technology could potentially narrow down our cost predictions to the tune of billions of pounds and help drive out risk.”

Listening skills

Using sound to help map our surroundings is nothing new – animals such as bats and dolphins have been using echolocation for millions of years.

It took humans a lot longer to unleash the potential of sonar. Leonardo da Vinci carried out the first recorded experiment in water acoustics in 1490, by lowering a tube into the ocean to listen out for passing ships. But it wasn’t until the turn of the 20th century that mankind began to unlock the potential of sound navigation and ranging, or sonar as it is better known. American naval scientists first used it sporadically from 1906 to detect icebergs – however it was the sinking of the Titanic in 1912 that brought the importance of sonar to the fore. The First World War and the race to detect the movement of submarines also drove technical innovation.

While the principle of working out what’s in the water by measuring the length of sonic echoes remains the same, today’s technology is a million miles from those first sonic pings 110 years ago. Now sonic probes fire millions of pulses which shape incredibly detailed 3D images in a ‘point cloud’. The mapping of the magazine transfer bay in the First Generation Magnox Storage Pond comprised around 24 million of these ‘points’.

Now that there’s a better understanding of exactly what’s in there, the team can plan far more effectively on how to empty and decommission the bay, building on the work carried out to bring the adjoining Magazine Maintenance Facility back into service in February 2016. The facility can now receive the blocked magazines from the bay so the team can work on dislodging the fuel bars and getting
the waste out.

This article was commissioned by Sellafield Ltd ( and has been reproduced by kind permission.