Retrieval is the recovery of waste from its current position, either for inspection purposes, for subsequent disposal or further storage in new packages or facilities.
Retrieval of radioactive waste refers to the collection and movement of waste to a more safe or secure condition/location/package. The need to retrieve waste arises either as part of the remediation and decommissioning of a nuclear facility, or if there are significant safety or security risks associated with the waste in its current state.
In some cases, retrieval of waste is less complex as storage facilities may be designed to allow reversal of emplacement technologies to allow for retrieval. Others may require the installation of specific or bespoke retrieval equipment at the appropriate time.
Waste retrieval occurs in several stages; identifying a need for retrieval, creating a framework of factors that can affect this, characterising the waste and facility, planning and implementing retrieval methods or technologies, and carrying out safe operations.
For new waste management plans, retrieval plans are put in place prior to work being undertaken. This is not always the case with legacy waste, which often presents unique challenges requiring a range of retrieval methods to be considered.
Case study
Magnox ILW retrievals at Nuclear Restoration Services (NRS)
Across NRS sites nearly 11,000m3 of intermediate level waste (ILW) needs to be retrieved and carefully and appropriately managed during initial decommissioning works before it can eventually be transferred to a Geological Disposal Facility (GDF).
ILW becomes a site’s highest radiological hazard once all the spent fuel is removed and is often stored in hard-to-reach areas. This means that the task of retrieving the waste is a complicated business requiring many years of engineering work before it can begin.
Once all the retrieval plant is installed and operational, the waste operations team is charged with the retrieval and packaging of the waste. NRS’ ILW Package Compliance Manager said: “Waste is our core business and now, more than ever, we are proving that we are the experts. In the recent past NRS has overcome a multitude of issues. These include dust management, high dose rate items within the waste, and perhaps most challenging, complete plant failures which have required investigation, development of a repair method and then performing the repair in a contaminated environment – which is anything but easy. What will always remain clear is that we need the whole of NRS to come together to overcome these hurdles and help achieve our ILW retrieval mission.”
As of 2024 there are ILW retrieval projects underway at seven NRS sites, with some nearing completion and others in their early phase. In 2023/24 approximately 175m3 of ILW was retrieved across NRS sites with large contributions from Berkeley vaults, Hinkley Point A fuel element debris (FED), Hunterston bunkers and Trawsfynydd active waste vaults. Sites such as Hinkley Point A and Berkeley have been able to take some learning from experience gained at Hunterston and Trawsfynydd making their retrieval process more efficient.
NRS’ Waste Operations Programme Manager added: “Though there are some similarities, all sites are different, and the waste behaves differently. We have had to become our own experts on a short and steep learning curve, ready to react to the challenges the waste presents. A degree of flexibility with the plant, process and people is a must. As we become more familiar with the waste, and share knowledge and learning with each other, we are demonstrating our expertise and retrieving more waste more consistently. Our success is due to working collaboratively, rather than having a single site approach. We are over halfway (over 6,000m3) through the NRS ILW retrievals programme, but among the remaining waste is some of the hardest ILW to process in terms of access and retrieval methods, so we have some challenging years ahead.”