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Rating: Compared to financial year 2024/25-Q4, the NISTA/SRO Delivery Confidence Assessment rating at 2025/26-Q4 remained at Amber. This is primarily due to the following factors. 1. Reflects ongoing challenges and a testing supply chain environment, despite positive developments such as improved understanding of the remaining scope and cost to completion, better schedule adherence, and progress towards completing construction prior to commissioning and handover.

Schedule: Exempt under Section 24 - National security

Cost: Compared to financial year 24/25-Q4, the project's departmentally agreed Whole Life Cost at 25/26-Q4 increased from £2929.600 to £2930.500. This is primarily due to the the agreed position presented by AWE at the last Financial Year and the change to a new Financial Year.

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

Rating: Compared to financial year 23/24-Q4, the Delivery Confidence Assessment rating at 24/25-Q4 remained at AMBER. This is primarily due to the following factors. The programme continuing to improve its understanding of the remaining scope and cost to completion, improvement of schedule adherence and progress towards finishing construction before commissioning and handover.

Schedule: Section 24 - National security

Cost: Compared to financial year 23/24-Q4, the project's departmentally agreed Whole Life Cost at 24/25-Q4 (measured in £m) increased from 2744 to 2929. This is primarily due to the following factors. An uplift in budget to £2929.6M has been approved to enable the project to continue delivering in the face of increasing material and labour costs.

Source: NISTA Annual Report 2024-25 (data)

Rating: Compared to financial year 22/23-Q4, the Infrastructure and Project Authority's Delivery Confidence Assessment rating at 23/24-Q4 remained at Amber. This is primarily due to the following factors. The project has been challenged to maintain pace whilst managing a complex schedule and a testing supply chain environment. The project continues to make progress and is nearing finishing construction.

Schedule: The project has been challenged to maintain pace whilst managing a complex schedule and a testing supply chain environment. The project continues to make progress and is nearing the completion of construction.

Cost: Compared to financial year 22/23-Q4, the project's departmental-agree Whole Life Cost at 23/24-Q4 increased from 2161m to 2744m. This is primarily due to the following factors. Prolongation associated with the projects complexity and interdependencies between supply chain partners, as well as supply chain performance, capability and capacity. The project remains affordable and within its Whole Life Costs budget.

Source: IPA Annual Report 2023-24 (data)