DEFUELING AGRS | COVER STORY


would have been a practical option, particularly given the short time available before defueling was due to start”. The government agreed financial incentives to


encourage EDFE to accelerate defueling and transfer of the stations. These incentives are weighted towards the defueling stage; up to £86m (US$115m) was available for good performance or EDFE can incur costs of up to £100m (US$134m). “They reflect the greater certainty about the defueling requirements compared with the less developed plans for EDFE’s work to support transfer, and the greater financial significance to the Fund of EDFE’s performance in defueling the AGR fleet compared with its preparations for transferring the stations and its involvement in preliminary deconstruction work,” said the report.


From theory to practice In fact, by the time the NAO report was published in 2022, EDFE had already been working on preparation for the defueling programme for several years. As head of AGR defueling support, Matt Exton has been involved in the defueling programme since 2017, which at that time was expected to be six years prior to the end of generation. That was the point at which he and his team began an end to end examination of the process, not only from the point of view of a single station but across the industry – including Sellafield, which as the NAO highlighted, is the destination for the fuel and therefore an integral part of the process. Exton and his team designed a holistic collaboration


programme. He says: “Six years out we judged was about the right amount of time” because it would allow time for the necessary ‘category one’ safety cases to be completed. The team expected to have three years lead time at each station before the end of generation, but were able to accelerate that when an early closure at one plant brought its overall preparation period down from six to four and a half. Exton explains that the programme had three components: “We prepared the station, we prepared the fleet and we prepared the industry”.


Preparing the station At the station level, safety cases were first on the agenda. Defueling of the AGR fleet is subject to regulation and scrutiny by the Office for Nuclear Regulation (ONR). Exton says there were lots of safety cases, from big ones such as modifying the flask corridor to small local ones, but a key one was for the people and the process. Next came hardware modifications. The team’s analysis had confirmed that the biggest constraint was the ‘flask corridor’, where fuel that has been removed from the reactor is dismantled into its component elements. It required major redesign. The buildings and plant remain the same, but EDFE built in multipurpose platforms in the three bays that allow for multiple tasks at once. The reconfigured layout now allows three flasks to be processed at a time and the team can process five to seven flasks a week if needed. The biggest constraint now is how quickly fuel can be removed from the reactor – something that cannot be modified. This experience has been passed on and the corridor


constraint has now been removed at all AGRs, some for immediate use and some ready for when defueling begins. Replication is a major principle of the programme, and although the sites are dissimilar, with different layouts and equipment such as cranes, EDFE used the same partner companies and made the changes as replicable as possible.


Exton says, “Depending on which site you are at there are different layouts, but now they all have that minimum throughput”.


One of the most important safety cases was focused on the people and the process. Exton says the process-mapping initiated a number of modifications: “But we knew we needed to resource the people differently”. There was no longer a need to refuel the reactor, for


example, or maintain the turbines. Instead, defueling required more fuel rig operators, as well as more staff on the pile caps to take the fuel out and at the pond and flask corridor area to package the fuel and send it off. The company trained more fuel rig operators before defueling started. Approximately 30 operations staff were retrained per site to be competent to work on the fuel route plant – the new critical path process for defueling an AGR site. An additional six fuel-route-trained operators in each of the five shifts were required to optimise the process. These 30 people increased the fuel route trained operations staff by around 50%, compared to the generation phase. The pool of people with these skills has increased and


there will be an opportunity for staff to potentially use this new specialism at other sites in the fleet as they defuel.


Preparing the industry The end-to-end process-optimisation in practice had to be a holistic industry-wide examination, encompassing everything from taking fuel from the reactor to its arrival in a pond at Sellafield. An industry-wide AGR Operating Programme (Agrop)


was set up in 2015 by the government, EDFE, the NDA and a Defueling Steering Panel to provide management and oversight of the defueling of the AGR fleet. It follows a similar pan-industry Magnox operating programme (MPO), employed when that earlier fleet was being defuelled. AGROP was praised in the NAO report, which said, “mid-programme health review of AGROP representatives from the Fund, EDFE and the NDA concluded in December 2020 that the management arrangements were appropriate and mature enough to deliver the preparation phase with good evidence of cross-industry experience being used”. One cross-industry process that will increase rapidly is the


transport of the fuel from EDFE sites to Sellafield, which is by a company called Direct Rail Services. But industrywide, the biggest issue was the waste destination at Sellafield. Defueling a plant means exporting at least three times as much fuel in a week as a generating site, so the demand on Sellafield increased dramatically - but the dismantler at that site had a ceiling to its capacity. It is a single point of vulnerability: “There are seven plants in our AGR fleet that need to send spent fuel, but there is only one plant that can receive it,” Exton says. Exton says Sellafield changed its manning, made some


modifications to the dismantler, and looked at reliability as part of AGROP.


Preparing the fleet The third aspect of the programme was preparing the set of ‘fleet assets’ used to transport the spent fuel, for example the spent fuel flasks. EDFE had enough flasks in operation to cope with the demand during the generation phase, but not enough for the bigger throughput. However, it also had some spares that had never been used, which it had held for 30 years. EDFE spent three or four years refurbishing these to


www.neimagazine.com | January 2026 | 23


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45