Clean up of the Sellafield site has taken a significant step
forward with the first removal of waste from the Pile Fuel
Cladding Silo.
It’s a plan that’s been decades in the making but this week saw
the achievement of a momentous milestone in the decommissioning
story at Sellafield as the first batch of waste was successfully
retrieved from the site’s oldest waste store.
After weeks of preparation and checks, the Pile Fuel Cladding
Silo retrievals team gathered around the monitors in the control
room of the 70-year-old plant to witness the moment a
state-of-the-art robotic arm reached into the silo to remove and
repackage waste for the first time.
Built in the 1950s to store cladding from used nuclear fuel from
the Windscale Piles – the first nuclear reactors to be built at
Sellafield – the vast concrete silo was designed as a ‘locked
vault’ with no plan for how to retrieve its contents or
decommission the building.
Cladding is the term used for the metal casing that surrounded
the uranium fuel rods that were loaded into nuclear reactors.
After the rods had been used in the reactors the cladding was
peeled away so the fuel inside could be reprocessed. Today we
class this cladding as intermediate-level nuclear waste.
After almost 20 years of operations the silo’s 6 compartments
were filled and it stopped receiving waste in the early 1970s.
In the years that followed the building underwent several
upgrades to ensure it could continue to store its contents safely
while a plan for retrievals was developed.
Today it represents one of the most complex and difficult
decommissioning challenges in the world and one of the highest
priorities for Sellafield Ltd and the Nuclear Decommissioning
Authority (NDA).
In the last decade a giant concrete superstructure has been built
around the silo and specially engineered shield doors have been
installed on each of its 6 compartments. In 2017 holes were
successfully cut in the top of each compartment, allowing access
to the waste for the first time in 65 years.
Working in collaboration with Bechtel Cavendish Nuclear
Solutions, Sellafield Ltd then designed, manufactured,
tested, and installed 9 huge modules containing the machinery
needed to empty the silo.
Successful testing of the robot grab was carried out earlier this
month, paving the way for the historic achievement of the first
waste retrievals from the silo.
Operators used the grab to remotely reach into the silo and pick
up the waste before loading it into a specially designed
stainless-steel box.
Once filled the box will be loaded into a shielded flask and
transported to a brand new, fit-for-purpose store called the Box
Encapsulation Plant Product Store.
Retrievals from the silo mark a significant step forward in the
clean-up and decommissioning of one of the most hazardous
buildings on the Sellafield site.
Euan Hutton, chief executive officer of Sellafield Ltd said:
The first retrievals from the Pile Fuel Cladding Silo are a huge
step towards delivering our purpose of creating a clean and safe
environment for future generations.
This achievement means that for the first time ever Sellafield is
retrieving waste from all four of our legacy ponds and silos.
This represents the culmination of years of effort by hundreds of
people throughout our organisation and contractor community. I am
enormously proud of all of them.
David Peattie, NDA chief executive officer, said:
This is an important milestone, demonstrating tangible progress
in delivering our mission and cleaning up some of our most
hazardous legacy waste.
It’s progress that has been years in the making and has been
driven forward by skilled, industry leading specialists working
collaboratively.
The ability to now retrieve waste from all four legacy ponds and
silos at Sellafield is a huge achievement and I’d like to extend
my congratulations and gratitude to everyone involved.
Mike Higgins, Pile Fuel Cladding Silo programme manager for
Bechtel Cavendish Nuclear Solutions, said:
Getting to this position, over the last 12-years, is testament to
the hard work, dedication and collaboration of the team, our
joint venture partners Cavendish Nuclear, alongside our customer
and all our supply chain partners.
Paul Dicks, Office for Nuclear Regulation director of regulation
- Sellafield, Decommissioning Fuel and Waste, said:
Ensuring that legacy waste is safely removed from the Pile Fuel
Cladding Silo and placed into storage facilities that meet modern
safety standards is a priority for ONR.
Our team of specialist inspectors rigorously assessed
Sellafield’s safety case submission until we were satisfied that
it was safe for retrievals to commence from the facility, and we
will continue a programme of regulatory oversight.
Further reading
Pile Fuel Cladding Silo -
case study
First hole is cut in
world’s oldest nuclear store
