One of the UK’s most hazardous buildings at Sellafield is closer to being cleaned up after delivery of a huge piece of decommissioning kit.
A 50 tonne ‘transfer tunnel’ arrived at the Sellafield site, ahead of being hoisted into place in the Magnox Swarf Storage Silo building.
The tunnel is the main component of the first Silo Emptying Plant (SEP) – one of 3 massive 360-tonne machines which will scoop out the highly radioactive contents of the building as part of its decommissioning.
The silo, which was built in the 1960s, contains waste created during the early days of the nuclear industry. It represents one of the Nuclear Decommissioning Authority’s 4 highest priority decommissioning jobs. The other 3 are also at Sellafield.
The silo is now well beyond its operational life and its contents must be removed so they can be stored in more modern facilities before the material is ultimately consigned to the UK’s geological disposal facility.
Installing such a large and weighty piece of kit into a 50-year-old building, containing some of the most hazardous material stored anywhere in the UK, is a huge, logistical challenge.
The metal structure, which was manufactured by Ansaldo NES at its engineering base in the West Midlands, first had to be transferred to a warehouse about 2 miles from the Sellafield site.
It was then sent to the site at walking pace on a flat-bed truck operated by a ‘driver’ following behind the load.
The next morning it was hoisted up into the silo building through a gap with only 20mm clearance either side and secured in place.
Attention will now turn to delivering the remaining components of the SEP machine so it can be assembled in situ before it can begin retrieving waste. Retrievals are currently scheduled to start in 2018. Production of the 2 remaining SEP machines is still ongoing.
The start of waste retrievals at the silo will mark the beginning of approximately 2 decades of work, with the final material expected to leave the building in about 2038.
Chris Halliwell, Head of the Magnox Swarf Storage Silo programme for Sellafield Ltd, said:
This is a big moment for us all.
It is fantastic to see the installation of the first part of the first machine that is going to get the waste out so that we can make this building far safer.
We need to get this material out as soon as possible to reduce the overall risk.
Everything at Sellafield is done with safety first and foremost in our minds.
This is one of the nuclear industry’s most complicated engineering challenges being addressed before our very eyes. This is cutting edge technology at the world’s most complicated nuclear site.
Sellafield Ltd announced in October that it expects the silo to be cleaned up quicker and for about £1bn less than originally planned following a switch to a simpler method of treating and storing the material.
The original plan to treat the waste via a complex 22-step method has been shelved in favour of a ‘raw waste’ storage option that simply places the material untreated into containers, with a final finishing step added prior to its consignment to the geological disposal facility.
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