The Magazine for Underwater Professionals
No task too tough with the right plan
We occasionally hear that a diving job has been avoided or has been completely abandoned because the client has an ill-conceived impression that all diving work is dangerous and carries with it unwarranted risk.
It is reassuring therefore to hear that despite these reservations, diving contractors can and do demonstrate that conducting diving operations does not have to be unduly hazardous – with the right planning and preparation, even the most challenging task can be completed safely underwater. The project summary that follows is a great demonstration of this point.
Somewhere in the UK right now, a diving team is at work doing a very specialised job; the difference with this job is that the diving team have led the way, convinced non-believers about what is possible, and set a high standard for various attendant work groups and support personnel to follow.
In a significant step forward for nuclear decommissioning activity in the UK, divers are being used to clean up the former cooling ponds at a now disused site.
The underwater activity is bringing with it a host of safety and environmental benefits. The work will see the pond skips that were once used to store used nuclear fuel cut up and packaged for disposal underwater, with the water that remains in the ponds acting as additional radiation protection for the divers. The technique also has additional environmental benefits, as the alternative of cutting skips after they have been removed from the ponds would require additional measures to prevent potential airborne contamination.
In the recent past during electricity generation, the ponds were used to store used nuclear fuel in skips before it was sent off site for reprocessing. The site has been fuel free for more than four years but the skips, which are classed as intermediate level waste, need to be disposed of safely.
One of the closure team said: “The use of divers was a change in our way of working. We have successfully shown through trials that this work can be carried out safely and we are now making good progress in the clean-up of the cooling ponds.”
Once cut up, the skips will be stored in approved waste containers in a shielded storage area on site before they are packaged for interim storage.
During the work, an additional 20 tonnes of pond furniture, including framework and machinery, classed as low level waste, will be removed and cut up before being disposed of at the Low Level Waste Repository in West Cumbria.
The learning from the work at this site, which is expected to be completed in early 2017, will be passed on to other nuclear sites where similar work will be carried out in the coming years.
A senior member of the management team commented: “We always encourage our contractors to adopt the highest standards of safety, security and environmental responsibility. The diving team involved in this work shows that they are making real progress in clearing the ponds at this site, in a way that is not only safe for the environment, but is also saving time and money.”
Roger O'Kane, ADC Secretary