Hi-tech "Worm" Probes Subterranean Pipeline
19th February 2009
A hi-tech "worm" is probing a subterranean pipeline used to discharge radioactive effluent from Dounreay between 1957 and 1992.
The £100,000 pipe crawler has sent back video and radiation readings during its five-day journey some 45 metres underground.
The data will be analysed by a project team investigating how to leave the disused system in a safe condition as part of the site clean-up.
A bundle of four cast iron pipes, each 23cm in diameter, was laid in the 1950s to discharge effluent from the fast reactor experiment.
It was connected on the surface at one end to two disused tanks where effluent drained from the reactors, chemical plants and waste facilities.
The pipeline bundle descends towards the sea along a sloping adit to a tunnel excavated 25 metres beneath the seabed.
At the end of the tunnel, some 600 metres offshore, the pipeline terminated in a diffuser attached to vertical risers that exited on the seabed 20 metres beneath the waves.
The pipes were encased in a thick concrete sleeve that runs along one side of the tunnel. When construction finished in 1957, the tunnel was abandoned and allowed to flood.
"The tunnel system has been flooded for more than half a century and the pipeline itself was taken out of routine use in 1992, so we don't know what condition the pipeline is in or if it safe to leave in place," explained Martin Howse, project manager with Dounreay Site Restoration Ltd.
"The remotely-operated vehicle will allow us to inspect the inside of the pipes. We are looking for signs of structural degradation, trapped debris and radioactive contamination.
"The findings will allow us to reach some judgements about the best course of action. It is our intention to present a proposal to the Scottish Environment Protection Agency by December."
The performance of the subsea discharge system started to deteriorate in the late 1970s. It was taken out of routine use in 1992 after a new plastic pipeline was installed in the tunnel and connected to a modern diffuser on the seabed.
Two companies with specialist remote inspection skills honed in the North Sea are carrying out the survey - MSIS and Hydropulsion.
The head of the "worm" is 2.5 metres long and 15cm in diameter. Its flexible tracked chassis can turn through bends in the pipes. An umbilical "tail" allows the pipeline crawler to be controlled remotely from the surface, where the project team can view "live" video and radiation readings.
Related Businesses
Related Articles
More than 140 graduates have started at Sellafield Ltd. Over 140 graduates have just started their exciting careers with the company in a range of business and technical disciplines, supporting Sellafield Ltd in its mission to create a clean and safe environment for future generations.
Find out what has been happening at UKAEA in our monthly newsletter. Read about our recent activities and upcoming events.
The Nuclear Decommissioning Authority (NDA) group has on 26 September 2024 published its 2023 to 2024 socio-economic report detailing a record investment in projects across the UK. Over the last five years, the NDA group has invested £60 million in projects that enable permanent and sustainable change in its site communities, leveraging many millions more from partners.
Today, the ponds inside the Thermal Oxide Reprocessing Plant (or as we like to call it, Thorp) are used to store nuclear fuel that has been used in the UK's 7 operational nuclear reactors. Before taking on this new mission, Thorp reprocessed 9,000 tonnes of used nuclear fuel from around the world, generating an estimated £9 billion in revenue for the UK over 2 decades.
Over 100 graduates join the Nuclear Decommissioning Authority group today as applications open for 2025. As applications open for 2025, the Nuclear Decommissioning Authority (NDA) group also welcomed its largest ever cohort of graduates today, with more than 100 new recruits ready to support delivery of one of the world's most important environmental programmes.
In a world-first, a fully autonomous robot has been used to inspect the inside of a fusion energy facility. In a world-first, a fully autonomous robot has been used to inspect the inside of a fusion energy facility.
At the Nuclear Decommissioning Authority biannual stakeholder summit, CEO David Peattie announced up to £5 million over five years to support around 20 PhDs. On the 17th and 18th of September the Nuclear Decommissioning Authority (NDA) hosted its biannual in person stakeholder summit, bringing together over 170 delegates from national and local government, the nuclear sector and site communities.
This year's cohort of apprentices and graduates will help drive forward work at the UK's largest and most complex nuclear site. Up to 300 vocational and degree apprentices and 150 graduates are expected to join Sellafield Ltd in this year's intake.
A repeating tone - blip, blip, blip - is the audible reminder that we are in one of the most hazardous nuclear sites in the world: Sellafield. That sound - pulsing from speakers inside the cavernous fuel-handling plant - is a signal that everything is functioning as it should.
Nuclear Decommissioning Authority (NDA) group publishes overview of progress being made against sustainability goals. The Nuclear Decommissioning Authority (NDA) group has today published an overview of progress being made against its sustainability goals.