Great British Energy – Nuclear has moved a proposed £730m–£1.1bn early works package at Wylfa on Anglesey into preliminary market engagement, bringing civils, earthworks, infrastructure, buildings and MEP together under a single planned procurement.
No early works contractor has been appointed and the formal tender has not yet been issued. An updated Find a Tender preliminary market engagement notice shows GBE-N currently expects to publish the tender notice on 1 March 2027, with an estimated contract commencement date of 1 June 2028.
The package is one of the clearest construction opportunities yet to emerge from the UK's first small modular reactor programme. It follows the separate technology agreement signed with Rolls-Royce SMR earlier this year, which LCM examined in its previous analysis of the Wylfa SMR delivery programme.
CGI of the proposed Wylfa small modular reactor development on Anglesey.
What GBE-N Is Asking the Market to Deliver
GBE-N's August 2026 commercial pipeline lists the requirement as “Early Works – Civils, Infrastructure, Buildings & MEP and Earthworks”.
| Wylfa Early Works | Current Position |
| Client | Great British Energy – Nuclear |
| Current stage | Preliminary market engagement / pre-procurement |
| Estimated contract value | £730m–£1.1bn |
| Estimated tender notice | 1 March 2027 |
| Estimated contract commencement | 1 June 2028 |
| Estimated core term | 72 months to 1 June 2034 |
| Extension option | Up to 36 months, potentially to June 2037 |
| Design | From RIBA Stage 4 |
| Intended procurement procedure | Competitive flexible procedure |
| Contractor appointed? | No |
The confirmed construction scope includes species relocation, remediation, site clearance, site establishment and construction utilities, together with drainage and haul roads required to support bulk earthworks. The earthworks are intended to establish the required ground levels and safe access routes for later phases. The package title also explicitly includes civils, infrastructure, buildings and mechanical and electrical work, while the design element begins from RIBA Stage 4. The notice identifies the procurement as particularly suitable for SMEs, although the eventual subcontracting strategy and individual Tier 2 and Tier 3 packages have not yet been publicly confirmed.
Why GBE-N Combined the Civils and Earthworks
GBE-N had previously considered separating the work into two packages. The client has now consolidated the scope into one procurement in order to “minimise interface risk”. That decision is more important to the supply chain than the headline value alone. Ground levels, haul roads, drainage, temporary utilities, site establishment and the infrastructure needed for later construction are physically dependent on each other. Delivering them through one procurement gives GBE-N a single commercial structure across those interfaces rather than dividing tightly connected site-readiness activities between separate contracts.
The inclusion of design from RIBA Stage 4 also makes this more than a bulk-earthworks opportunity. The eventual supplier will need to integrate technical design with the sequencing and delivery of multiple civil, infrastructure, buildings and MEP elements. This is consistent with the wider shift identified in LCM's analysis of the UK nuclear programme moving into infrastructure delivery, where site development, civil engineering, logistics and supply-chain integration increasingly sit alongside the reactor technology itself.
The £1.1bn Figure Is Not a Contract Award
The most important procurement distinction is what the £1.1bn figure actually represents. It is the upper end of GBE-N's estimated value range for the proposed future early works procurement. It is not an awarded contract, committed expenditure or confirmed construction budget.
GBE-N's commercial pipeline separately records the value of the possible 36-month extension as “tbc”. The available evidence therefore does not support describing £1.1bn as a maximum value including the extension option. The pipeline itself carries an explicit warning that the information is a forecast of potential procurement activity and remains dependent on resources, budgets, prioritisation, governance and business-case approvals. GBE-N also says scope, dates, values and sequencing may change as the programme develops.
| Procurement Stage | Status at 8 September 2026 |
| Commercial pipeline published | Yes |
| Preliminary market engagement | Yes |
| Supplier webinar | Held 3 September 2026 |
| Formal tender notice | Not yet issued – currently estimated 1 March 2027 |
| Preferred bidder | No |
| Early works contract award | No |
| Estimated contract commencement | 1 June 2028 – indicative, not a confirmed site start |
| Main SMR construction | Separate later stage |
Rolls-Royce SMR Has a Separate Technology Contract
The early works procurement should also not be confused with the contract GBE-N signed with Rolls-Royce SMR on 13 April 2026. Rolls-Royce SMR was selected as preferred technology partner in June 2025 and subsequently entered into contract with GBE-N to begin site-specific design, regulatory engagement and planning work ahead of a future Final Investment Decision.
That technology contract relates to the three-unit SMR programme, which GBE-N says will provide at least 1.4GWe. Rolls-Royce SMR has not been appointed as the contractor for the £730m–£1.1bn early works package. For construction firms, that creates two clearly different streams: Rolls-Royce is progressing the reactor technology and site-specific design programme, while GBE-N is separately developing the client's early works, infrastructure and wider construction procurements.
Wylfa Is Not Yet Cleared for Main SMR Construction
The procurement programme should not be read as evidence that main reactor construction has started or has received all necessary approvals. The Office for Nuclear Regulation currently lists the Rolls-Royce 470MW SMR design in Step 3 of Generic Design Assessment. ONR has separately confirmed that the GDA assumes a generic Great Britain site rather than Wylfa specifically.
That distinction matters. Generic Design Assessment examines the reactor design; it is not a site-specific planning permission or nuclear site licence for Wylfa. Site-specific regulatory, planning and environmental processes, together with the programme's future Final Investment Decision, remain separate from the current early works market engagement. The estimated June 2028 contract commencement date should therefore be reported for what it is: an indicative procurement programme date. It is not confirmation that enabling works will physically begin on that date, and it is not a main SMR construction start.
What the Wylfa Supply Chain Should Watch Next
GBE-N completed its preliminary market engagement webinar on 3 September and subsequently updated the procurement notice to make the webinar material available. Suppliers can request the presentation and questionnaire from GBE-N, while future procurement notices and information are expected to be issued through its Jaggaer e-sourcing portal. For civils and specialist contractors, the confirmed scope already points towards future demand across bulk earthworks, remediation, drainage, haul roads, construction utilities, site establishment, buildings and MEP. Opportunities for piling, testing, surveying, temporary works, plant, concrete, steel and other specialist packages are plausible within a programme of this scale, but their procurement structure is not yet publicly confirmed and will depend on the final tender and eventual delivery strategy.
The scale also sits within a much wider publicly backed nuclear investment programme. LCM's examination of how public finance is shaping the UK construction pipeline previously identified SMRs as one of the major areas where government-backed capital is beginning to translate into design, site preparation and future infrastructure workload. The next meaningful milestone for this particular package is the formal procurement itself. GBE-N currently estimates publication of the tender notice on 1 March 2027. Until that happens, the £730m–£1.1bn early works opportunity remains a market-tested future procurement rather than an awarded construction contract.
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Expert Verification & Authorship: Mihai Chelmus
Founder, London Construction Magazine | Construction Testing & Investigation Specialist |
