# Reactor Buildings Height Reduction \(EXECUTION phase\)

> A sourced UK public sector contract award published by Nuclear Restoration Services Ltd.

## Key facts

- Buyer: [Nuclear Restoration Services Ltd](/buyers/nuclear-restoration-services-ltd/contract-awards)
- Supplier: [Costain Limited](/suppliers/costain/public-sector-contract-awards)
- Award value: £71,813,292
- Tender value: £71,813,292
- Award date: 2 October 2025
- Published: 7 October 2025
- Contract start: 6 October 2025
- Contract end: 29 March 2029
- Stage: awarded
- Procurement category: works
- Notice ID: 943f87d4-79ed-4bb5-80d5-226109eec436-867207
- OCID: ocds-b5fd17-b2d6aadb-d278-4c55-b3a4-a286427e08d5

## Description

The existing Reactor Buildings at Trawsfynydd are now life expired and require works to mitigate against further degradation, thus ensuring they remain safe and compliant for subsequent decommissioning activities\. In addition there are long term commitments through the Town and Country Planning process to reduce the visual impact the buildings currently have on the landscape within the Snowdonia National Park\. The Height Reduction project has therefore been implemented with the objective of reducing the height of both reactor buildings such that they are left in a safe and stable configuration for the next phase of works to decommission the Trawsfynydd site whilst significantly reducing ongoing asset investment demands\. The reduction in height will also satisfy the requirements to lessen the visual impact the current full height buildings have within the Snowdonia National Park\.

## Related contract awards

- [Hinkley B IT Hardware 2026](/contracts/ocds-b5fd17-18b27c4c-49a8-44fc-bbd7-1c37081b3b9e) — Nuclear Restoration Services Ltd
- [Harwell Groundwater Treatment Plant Post Closure Monitoring](/contracts/ocds-b5fd17-dc2b032e-68e6-43a6-9139-be12063a19b9) — Nuclear Restoration Services Ltd
- [OLA - Update Qualitative Risk Assessment, Land Quality Register & Map and APC](/contracts/ocds-b5fd17-ac59cff7-3bb9-4f68-9b10-47d166f8449d) — Nuclear Restoration Services Ltd
- [CHX Update Qualitative Risk Assessment, Land Quality Register & Map and APC](/contracts/ocds-b5fd17-b54151c7-c7ee-4e5d-8821-09a77a153cdf) — Nuclear Restoration Services Ltd
- [S30074 Floating Bus Stops - Research, Testing and Trials](/contracts/ocds-b5fd17-ea00d46a-ede7-4cd0-ae44-8552a8fc36b1) — National Highways Limited
- [SGHWR - D60 Crane - Scope Development](/contracts/ocds-b5fd17-596abd03-cdb2-43c2-a1ca-95c8cfdd8a2b) — Nuclear Restoration Services Ltd
- [S30051 HPEVCP Strategy feasibility - Co-located sites](/contracts/ocds-b5fd17-2a985b60-c561-4202-ab00-2d29ae2e4f88) — National Highways Limited
- [S30054 Suppression and Fighting Techniques for EV & Hydrogen Fuelled Fires](/contracts/ocds-b5fd17-5eebdea2-ce14-4c10-a934-76368b9b3f1e) — National Highways Limited
- [PAHT - ITU Dirty Utility Refurbishment](/contracts/ocds-b5fd17-321415b1-2fe9-4bf1-a2b5-079db2455bb3) — The Princess Alexandra Hospital NHS Trust
- [HD029-25 Peterhouse Road Grimsby](/contracts/ocds-b5fd17-9e1d3cb6-e20a-4bb5-a4c4-5ec2ac426a09) — North East Lincolnshire Council
- [DNWP0019/LOT1B/ WAGR / PIE ILW - Detailed Design](/contracts/ocds-b5fd17-558d7ec4-e768-4d6b-bcea-fe3a6571f542) — Sellafield Ltd
- [PRP318 Glenholme - Refurbishment Works](/contracts/ocds-b5fd17-cd44ca3f-0f62-4d33-920b-0bf7f6be6db3) — Derbyshire County Council

## Source

[View the original notice on Contracts Finder](https://www.contractsfinder.service.gov.uk/Notice/943f87d4-79ed-4bb5-80d5-226109eec436-867207)