Diamond Annual Review 2025-26

As of March 2026, the project is approximately a third through the time estimates and has either spent or committed 50% of the estimated cost to complete. We have taken occupation of the DEB and are putting it into operational use, and the construction of the 1MW data centre has started. Deliveries for technical equipment are starting to arrive in the facility and are being housed within the DEB or in a contracted storage facility a few miles away in Milton Park. In September 2025 a Project Assessment Review was held, led by three UK government Gateway-trained project delivery experts over three days. They spent time interviewing key stakeholders within the project team, across Diamond, funders and advisory committees. The review team assessed that “the project is being managed well; however, some risks remain which should be carefully managed. Overall, these risks seem to be understood by the project with mitigations planned”. The review team therefore set the current project delivery confidence assessment as ‘amber/green’. There has been significant effort across almost all areas of Diamond to progress the Diamond-II upgrade project this year. This is intentionally reflected in this annual review, as details on the progress of the upgrade are captured in the various technical sections and not just in this dedicated section. Diamond-II The review was very useful, pointing out areas to focus on to improve deliverability, beamline financial planning, and completion requirements clarity. It also recognised the concern of funding pressure within Diamond business as usual (BAU), which partially funds the project. The review also identified areas of good practice, noting strong project leadership and robust project management practices, recognising the value of stakeholder expertise to support delivery, and the value of shared learning and peer review from similar worldwide operations. In preparations for the dark period, Diamond recognises that minimising the time without user operations is key. We have set a series of readiness reviews every six months to take a critical look at progress, determining whether adherence to planned timeframes remains feasible. The first of these reviews took place in December 2025, concluding that the current timelines are achievable with successful mitigation of key risk areas. At the next review in June 2026, we will take another in-depth critical look and update users and stakeholders. A key review is planned for December 2026, as this will determine the details of last call to users for beamtime. Through this year, as project budgets have proved to be very robust, we have been able to release a further £13m of scope into the project within the available funding. However, as recognised in the Project Assessment Review, BAU funding is under pressure. Funding towards the project has been recognised and it is highly unlikely we will be able to release further scope without a change in funding or risk within the project. Due to this funding reduction, we are developing scenarios and options should risks realise and we need to take action. Diamond will monitor progress and risk over the coming years and attempt to maximise what can be delivered within the funding available. Figure 6: Diamond-II readiness reviews timeline CSXID Critical as will feed into User AP calls Start of dark period Dec 2025 Jun 2026 Dec 2026 Jun 2027 Dec 2027 39 40 Annual review 2025/26 Diamond-II