GovWire

One of the biggest challenges at Sellafield is the need to remove historical nuclear waste from its legacy ponds and silos and place it into safe, modern stores.

One such store is the Box Encapsulation Plant Product Store, a huge, purpose-built, above ground vault that can store intermediate level wastes safely and securely for the next hundred years.

The stores Direct Import Facility received its first box of waste this week after years of meticulous planning and testing by hundreds of people.

The Box Encapsulation Plant Product Store has the capacity to store 6,681 waste boxes inside its metre-thick walls, and can receive up to 9 boxes every 24 hours.

The Direct Import Facility is an annexe to the store, built to receive the packages of nuclear waste retrieved from ageing stores in the oldest parts of the Sellafield site.

Its first package contains waste from the Pile Fuel Cladding Silo, the oldest waste store at Sellafield that has stored over 3,200 cubic metres of intermediate level waste undisturbed for 70 years.

Constructed in the 1950s, the silo was used to store the metal fuel casings or cladding from nuclear fuel used in the UKs earliest nuclear reactors. It was designed as a locked vault with no plan for how it might be emptied in the future.

Today it represents one of the highest hazards on the Sellafield site, making the removal and repackaging of wastes from the silo a key priority for Sellafield Ltd and the Nuclear Decommissioning Authority (NDA).

The first batch of waste was successfully retrieved from the silo in August 2023, marking another historical first for the site and the culmination of decades of planning and preparation by generations of nuclear workers.

Giant shield doors were installed on the top of the silo to maintain a radiation barrier as holes were cut in the sides of the building to allow access to its contents.

The retrievals team then used a remotely operated crane to reach into the silo, lift out the waste and place it into a specially designed stainless-steel box.

Once filled, the five-tonne box was loaded into a shielded transport flask, monitored, and cleared for export to the Box Encapsulation Plant Product Store/Direct Import Facility.

Moving a flask of nuclear waste across a busy industrial site takes careful coordination from a range of teams, but a successful test run with a dummy package in 2020 proved this could be done smoothly and safely.

The flask was transported from the silo by road and lifted into the new store by crane.

Once inside, the flask has its lid bolts removed and is placed behind a shield door so operators can remotely remove the flask lid, lift out the box, and transfer it to its predetermined location in the store.

It will store the waste safely and securely until its ready for permanent disposal underground in a Geological Disposal Facility.

Euan Hutton, Sellafield Ltd CEO, said:

The receipt of the first box of waste into the Box Encapsulation Plant Product Store/Direct Import Facility marks an important breakthrough in the clean-up of our site and a huge step forward in our mission to create a clean and safe environment for future generations.

This would not have been possible without the hard work and dedication of hundreds of people over many years and Im extremely grateful to them and proud to celebrate this achievement.

David Peattie, NDA group CEO, said:

This is a significant achievement which will enable us to continue to deliver our vital mission and Id like to extend my thanks to everyone who has been involved for their commitment to the project.

Removing waste from the Pile Fuel Cladding Silo is one of our biggest challenges, this new facility is providing the storage capability to allow us to do that safely and securely.

It also provides future capability for retrievals from other high hazard facilities such as the Magnox Swarf Storage Silo.