---
title: "STEP Construction Partner (CP)"
ocid: "ocds-h6vhtk-0361bf"
canonical_url: "https://d3tenders.com/contract/?ocid=ocds-h6vhtk-0361bf"
markdown_url: "https://d3tenders.com/contract/ocds-h6vhtk-0361bf.md"
json_url: "https://d3tenders.com/contract/ocds-h6vhtk-0361bf.json"
source: "Find A Tender Service"
current_stage: "Award"
buyer: "UNITED KINGDOM FUSION ENERGY"
published: "2026-04-22"
---

# STEP Construction Partner (CP)

Buyer: UNITED KINGDOM FUSION ENERGY  
Current stage: Award  
OCID: ocds-h6vhtk-0361bf

[View canonical contract page](https://d3tenders.com/contract/?ocid=ocds-h6vhtk-0361bf)  
[Download OCDS JSON](https://d3tenders.com/contract/ocds-h6vhtk-0361bf.json)

## Summary

The United Kingdom Fusion Energy (UKFE), previously represented by UKAEA, has concluded a procurement process on behalf of UK Industrial Fusion Solutions Limited (UKIFS) for a Construction Partner under the STEP project, aimed at establishing a UK prototype fusion energy plant. The procurement falls under the works category, focusing on engineering and construction, and covers a significant effort to build industrial capabilities within the UK. Lot 2, specifically for the Construction Partner, will be aimed at comprehensive design and the construction of the STEP Prototype Plant's facilities, with a contract potentially extending up to 20 years. The procurement method used was selective, involving competitive dialogue, and the contract value is approximately £10 billion. The procurement is part of a long-term plan with key dates, such as the contract end term in March 2029, with optional extension periods up to 2049. The process initially included two lots, Lot 1 for an Engineering Partner that was later cancelled.

This tender offers substantial opportunities for businesses specialised in construction and engineering to engage in creating a significant energy infrastructure project. Companies with expertise in building complex, large-scale facilities, and managing diverse supply chains would be well-suited to compete in this long-term business opportunity. The partnership with UKFE aims to leverage existing and new supply chains for comprehensive design, procurement, fabrication, and installation tasks, presenting businesses with the chance to participate in cutting-edge fusion energy technology development. Large enterprises like ILIOS, already contracted as the supplier, reflect the scale of expertise and resources required for participation in this venture, ensuring that interested parties can contribute to building a world-leading fusion industry.

## Notice

UKIFS (now UKFE) has conducted this Procurement for a Construction Partner, who, together with a Fusion Partner (determined to be United Kingdom Atomic Energy Authority (UKAEA)), will bring together and develop extensive industrial capabilities to design and build a UK prototype fusion energy plant capable of delivering net-energy to the grid, and build a world-leading fusion delivery industry. The Procurement was originally divided into two lots: * Lot 1: Engineering Partner (EP) * Lot 2: Construction Partner (CP) However, Lot 1 - EP has since been cancelled. Lot 2 - CP is now the only Lot included in this Procurement exercise. The contract term for Lot 2 will expire 31 March 2029, followed by three (3) optional extension periods of four (4), six (6) and seven (7) years. UKFE will have the right to exercise an extension option at six (6) months' notice. The maximum contract duration will be twenty (20) years with an estimated value of PS10,000,000,000 across this period.

### Lot Information

Engineering Partner (EP)

The Engineering Partner's (EP) primary responsibility will be to provide the capability to drive the integrated design of the STEP Prototype Plant (SPP), and to then manufacture that plant through a developing supply chain. This includes (but not be limited to) providing capabilities for management of all engineering data, responsibility for the detailed design of SPP systems, equipment, and components, and contracting through the engineering supply chain. The EP will be responsible for leading a supply chain which delivers the manufacture and assembly of the SPP components. See the procurement documents for further details.

Renewal: The EP contract term will be an initial 3 year period, followed by 3 optional extension periods of 4, 6 and 7 years (these durations are subject to change as the Programme develops). UKIFS will have the right to exercise an extension option on 6 months' notice. The maximum contract length duration for the EP contract will be 20 years with an estimated value of PS10,000,000,000.

Construction Partner

The Construction Partner's (CP) primary responsibility will be to collaboratively provide the capability to drive the integrated design of the overall layout, buildings, infrastructure, onsite and offsite facilities of the STEP Prototype Plant (SPP) to fulfil the support, enclosure and environmental requirements of the operational plant. The CP will then purchase, fabricate, deliver and install all elements of the designed facilities utilising existing and new supply chains, directly sourced or contracted resources. The CP's responsibilities will include (but not be limited to) managing the overall health, safety, environment and security systems applicable to all parties engaged at the site. Additional information: Lot 1 for the Engineering Partner (EP) was cancelled and will not be awarded. Only Lot 2 for the Construction Partner (CP) forms part of this notice.

Renewal: The CP contract term will be an initial 3 year period, followed by 3 optional extension periods of 4, 6 and 7 years (these durations are subject to change as the Programme develops). UKIFS will have the right to exercise an extension option on 6 months' notice. The maximum contract length duration for the CP contract will be 20 years with an estimated value of PS10,000,000,000.

## Key Details

| Field | Value |
| --- | --- |
| Publication source | Find A Tender Service |
| Latest notice | https://www.find-tender.service.gov.uk/Notice/036554-2026 |
| Notice type | Planning Notice |
| Procurement type | Standard |
| Procurement category | Works |
| Procurement method | Selective |
| Procurement method details | Competitive dialogue |
| Tender suitability | Not specified |
| Awardee scale | Large |
| All stages | Planning, Tender, Award |

## Dates

| Field | Value |
| --- | --- |
| Publication date | 22 Apr 2026 |
| Submission deadline | 12 Jul 2024 |
| Future notice date | 29 Apr 2023 |
| Award date | 1 Apr 2026 |
| Contract period | Not specified |
| Recurrence | Not specified |

## Values

| Field | Value |
| --- | --- |
| Tender value | £20,000,000,000 |
| Lots value | £20,000,000,000 |
| Awards value | Not specified |
| Contracts value | £10,000,000,000 |

## Status

| Field | Value |
| --- | --- |
| Tender status | Complete |
| Lots status | Active, Cancelled |
| Awards status | Active |
| Contracts status | Active |

## Buyer

| Field | Value |
| --- | --- |
| Main buyer | UNITED KINGDOM FUSION ENERGY |
| Additional buyers | UNITED KINGDOM ATOMIC ENERGY AUTHORITY |
| Locality | ABINGDON |
| Post town | Oxford |
| Postcode | OX14 3DB |
| Country | England |
| ITL 1 | TLJ South East (England) |
| ITL 2 | TLJ1 Berkshire, Buckinghamshire and Oxfordshire |
| ITL 3 | TLJ14 Oxfordshire CC |
| Local authority | South Oxfordshire |
| Electoral ward | Sandford & the Wittenhams |
| Westminster constituency | Didcot and Wantage |
| Delivery location | Not specified |

## Supplier

| Field | Value |
| --- | --- |
| Number of suppliers | 1 |
| Supplier names | ILIOS |

## CPV Codes

### Divisions

- 45 - Construction work
- 66 - Financial and insurance services
- 71 - Architectural, construction, engineering and inspection services
- 79 - Business services: law, marketing, consulting, recruitment, printing and security

### Codes

- 45200000 - Works for complete or part construction and civil engineering work
- 45213250 - Construction work for industrial buildings
- 45214610 - Laboratory building construction work
- 45220000 - Engineering works and construction works
- 45222000 - Construction work for engineering works except bridges, tunnels, shafts and subways
- 45223000 - Structures construction work
- 45251000 - Construction works for power plants and heating plants
- 45251100 - Construction work for power plant
- 45251110 - Nuclear-power station construction work
- 45251111 - Construction work for nuclear reactors
- 45254200 - Construction work for manufacturing plant
- 66519000 - Engineering, auxiliary, average, loss, actuarial and salvage insurance services
- 71000000 - Architectural, construction, engineering and inspection services
- 71240000 - Architectural, engineering and planning services
- 71250000 - Architectural, engineering and surveying services
- 71310000 - Consultative engineering and construction services
- 71311000 - Civil engineering consultancy services
- 71312000 - Structural engineering consultancy services
- 71313000 - Environmental engineering consultancy services
- 71318000 - Advisory and consultative engineering services
- 71320000 - Engineering design services
- 71321000 - Engineering design services for mechanical and electrical installations for buildings
- 71322000 - Engineering design services for the construction of civil engineering works
- 71323000 - Engineering-design services for industrial process and production
- 71323200 - Plant engineering design services
- 71330000 - Miscellaneous engineering services
- 71333000 - Mechanical engineering services
- 71334000 - Mechanical and electrical engineering services
- 71336000 - Engineering support services
- 71337000 - Corrosion engineering services
- 71340000 - Integrated engineering services
- 71350000 - Engineering-related scientific and technical services
- 71500000 - Construction-related services
- 71520000 - Construction supervision services
- 71521000 - Construction-site supervision services
- 71530000 - Construction consultancy services
- 71540000 - Construction management services
- 71541000 - Construction project management services
- 79418000 - Procurement consultancy services

## Release History

- 22 Apr 2026 at 11:28 - Award - Award Notice - https://www.find-tender.service.gov.uk/Notice/036554-2026
- 12 Aug 2024 at 16:19 - TenderUpdate - Tender Notice - https://www.find-tender.service.gov.uk/Notice/025505-2024
- 8 Jul 2024 at 11:19 - TenderUpdate - Tender Notice - https://www.find-tender.service.gov.uk/Notice/020761-2024
- 22 May 2024 at 13:19 - Tender - Tender Notice - https://www.find-tender.service.gov.uk/Notice/016180-2024
- 18 Apr 2023 at 10:24 - TenderUpdate - Tender Notice - https://www.find-tender.service.gov.uk/Notice/011051-2023
- 10 Nov 2022 at 17:07 - Planning - Planning Notice - https://www.find-tender.service.gov.uk/Notice/031914-2022
- 25 Aug 2022 at 07:57 - TenderUpdate - Tender Notice - https://www.find-tender.service.gov.uk/Notice/023709-2022
- 24 Aug 2022 at 10:42 - TenderUpdate - Tender Notice - https://www.find-tender.service.gov.uk/Notice/023590-2022
- 22 Aug 2022 at 16:42 - Planning - Planning Notice - https://www.find-tender.service.gov.uk/Notice/023363-2022

## Notice URLs

- http://www.gov.uk/government/organisations/uk-atomic-energy-authority
- https://uk.eu-supply.com/app/rfq/rwlentrance_s.asp?PID=55832&B=UKAEA
- https://uk.eu-supply.com/app/rfq/rwlentrance_s.asp?PID=81210&B=UKAEA
- https://uk.eu-supply.com/ctm/Company/CompanyInformation/Index/72814
- https://www.gov.uk/government/organisations/uk-fusion-energy

## Provenance

This Markdown file is an alternate public rendering of the D3 Tenders contract record. The canonical page is https://d3tenders.com/contract/?ocid=ocds-h6vhtk-0361bf. The underlying structured data is available as OCDS JSON at https://d3tenders.com/contract/ocds-h6vhtk-0361bf.json.