GEOLOGICAL DISPOSAL FACILITY

Rating: Compared to financial year 24/25 the NISTA Delivery confidence assessment (DCA) rating at 25/26 remained at 'Red'. This is primarily due to the following factors, withdrawal of one of the remaining three community partnerships reducing the portfolio diversity, outcome of the full spending review settlement resulting in reduced programme scope delivery over the next few years and deferral of critical path activities in the move to the next phase. An action plan is in place to address the next steps as identified.

Schedule: Compared to financial year 24/25-Q4, the project's end-date remains in the range 2050-2060. This is primarily due to the following factors‚ the programme has continued to progress the site evaluation and community willingness activities during 25/26. The programme continues to prioritise activities in line with the available SR settlement funding.

Cost: The project's departmentally agreed Whole Life Cost at 25/26-Q4 (measured in £m) remains in the range of £20,300m to £53,300m at 17/18 money values. This is primarily due to the following factors: the programme is at an early stage of development, and the range reflects the uncertainty of the programme associated with potential host site, geology and technical requirements.

Source: NISTA Major Projects Annual Report 2025-26 (data)

Rating: Compared to financial year 23/24-Q4, the Infrastructure Project Authority's Delivery Confidence Assessment rating at 24/25-Q4 changed from AMBER to RED. This is primarily due to the following factors‚ The IPA review during January 25, and associated RED rating, reflects the unaffordability of the GDF Programme, with particular reference to the Preparations for Detailed Site Investigations OBC in respect of the forecast financial case and the 25/26 SR settlement. The programme continues to progress and will update the delivery plan to take account of the outcome of the upcoming Spending Review, protecting as far possible, the critical path, reducing uncertainty and mitigating the key risks. The four key programme objectives continue to be delivered by the programme.

Schedule: Compared to financial year 23/24-Q4, the project's end-date at 24/25-Q4 remained at 31/03/2050. This is primarily due to the following factors‚ There is no change at the end of 24/25 to the current forecast project end date. The programme continues to reduce uncertainties of delivery. The critical path has been held following the 25/26 SR settlement through prioritisation of activities.

Cost: Compared to financial year 23/24-Q4, the project's departmentally agreed Whole Life Cost at 24/25-Q4 (measured in £m) remained at 20300. This is primarily due to the following factors‚ There is currently no change to the Whole Life Cost Range for the programme which is £20.3bn to £53.3bn (2017/18 money values). This range reflects the uncertainty of the programme associated with potential host site, geology and technical requirements. The impacts of the Spending Review and other changes will be reflected in an update to the Programme Level Business Case during early 2026.

Source: NISTA Annual Report 2024-25 (data)

Rating: Compared to financial year 22/23-Q4, the Infrastructure Project Authority's Delivery Confidence Assessment rating at 23/24-Q4 remained at Amber. This is primarily due to the following factors. The DCA of amber reflects the uncertainty in the project at this time. There is still considerable uncertainty with the site locations, associated geology and technical feasibility as the programme moves towards the next phase as communities are selected to move to detailed site investigations or exited from the process. The programme continues to make good progress within this phase of community engagement and site evaluation across the main factors of willing community, suitable site and programme deliverability, in line with the Working With Communities Policy with the 3 existing Community Partnerships.

Schedule: Compared to financial year 22/23-Q4, the project's end-date at 23/24-Q4 remained schedule to finish on 2050-03-31. This is primarily due to the following factors. The indicative project end date is that given for the First Waste Emplacement of legacy radioactive waste in the facility, aligned to the Tranche 3 sub programme business case; this includes updated timescales in the securing of willing communities, a better understanding of the full scope of work to characterise the sites through the drilling of deep geological boreholes and associated consents and permissions and a level of schedule risk and uncertainty. It should be noted that the programme continues to face considerable uncertainties at this stage due to the site selection process; confidence will increase as the potential site locations are down selected and fully characterised. The schedule remains on target for the first key decision point - selection of preferred site(s) in 2026.

Cost: Compared to financial year 22/23-Q4, the project's departmental-agree Whole Life Cost at 23/24-Q4 remained at 20300m. This is primarily due to the following factors. The whole life costs align with those approved in the Programme Level Business Case (at 17/18 money values). The WLCs presented in the GMPP report cover both the HMG & non-HMG costs to the programme and are the lower bound estimate within the business case. The lower bound 20.3bn covers the lower possible technical complexity of the GDF site construction and includes provision for legacy waste, waste from new nuclear (16GWe) and other potential materials. The upper bound of the business case 53.3bn includes for higher technical complexity in the GDF construction site, contingency, optimism bias and uncertainty. As we move to preferred sites the level of uncertainty will significantly reduce.

Source: IPA Annual Report 2023-24 (data)