---
title: "Reactor Buildings Height Reduction (EXECUTION phase)"
ocid: "ocds-b5fd17-b2d6aadb-d278-4c55-b3a4-a286427e08d5"
canonical_url: "https://d3tenders.com/contract/?ocid=ocds-b5fd17-b2d6aadb-d278-4c55-b3a4-a286427e08d5"
markdown_url: "https://d3tenders.com/contract/ocds-b5fd17-b2d6aadb-d278-4c55-b3a4-a286427e08d5.md"
json_url: "https://d3tenders.com/contract/ocds-b5fd17-b2d6aadb-d278-4c55-b3a4-a286427e08d5.json"
source: "Contracts Finder"
current_stage: "Award"
buyer: "NUCLEAR RESTORATION SERVICES LTD"
published: "2025-10-07"
---

# Reactor Buildings Height Reduction (EXECUTION phase)

Buyer: NUCLEAR RESTORATION SERVICES LTD  
Current stage: Award  
OCID: ocds-b5fd17-b2d6aadb-d278-4c55-b3a4-a286427e08d5

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## Summary

The public procurement process for the "Reactor Buildings Height Reduction (EXECUTION phase)" at the Trawsfynydd site in Wales has been completed, with Nuclear Restoration Services Ltd acting as the buying organisation. This tender involved the selective procurement method through a competitive procedure with negotiation due to its value, which is GBP 71,813,292. The procurement focuses on works related to construction, civil engineering, and demolition within the Snowdonia National Park, primarily involving crane hire, site preparation, and clearance work. The contract was awarded to Costain Limited on 2 October 2025, and it is scheduled to run from 6 October 2025 until 29 March 2029, aligning with the overall objective of preparing the reactor buildings for future decommissioning by reducing their height and visual impact.

This tender presents significant opportunities for businesses involved in heavy construction and specialised engineering services, particularly those with experience in infrastructure decommissioning and environmental compliance. Companies providing crane hire, demolition, asbestos removal, and reinforced-concrete work are particularly well-suited to participate in such projects, potentially leading to long-term growth and engagement in similar decommissioning projects across the UK. The procurement's focus on competitive negotiation allows for flexibility in solution offerings, making it an attractive prospect for innovative businesses capable of efficient, sustainable construction practices.

## Notice

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.

## Key Details

| Field | Value |
| --- | --- |
| Publication source | Contracts Finder |
| Latest notice | https://www.contractsfinder.service.gov.uk/Notice/64653164-9879-4b04-8195-949ce6ff8677 |
| Notice type | Award Notice |
| Procurement type | Standard |
| Procurement category | Works |
| Procurement method | Selective |
| Procurement method details | Competitive procedure with negotiation (above threshold) |
| Tender suitability | Not specified |
| Awardee scale | Large |
| All stages | Award |

## Dates

| Field | Value |
| --- | --- |
| Publication date | 7 Oct 2025 |
| Submission deadline | 19 Dec 2024 |
| Future notice date | Not specified |
| Award date | 1 Oct 2025 |
| Contract period | 5 Oct 2025 - 29 Mar 2029 |
| Recurrence | Not specified |

## Values

| Field | Value |
| --- | --- |
| Tender value | £71,813,292 |
| Lots value | Not specified |
| Awards value | £71,813,292 |
| Contracts value | Not specified |

## Status

| Field | Value |
| --- | --- |
| Tender status | Complete |
| Lots status | Not specified |
| Awards status | Active |
| Contracts status | Not specified |

## Buyer

| Field | Value |
| --- | --- |
| Main buyer | NUCLEAR RESTORATION SERVICES LTD |
| Locality | TRAWSFYNYDD |
| Post town | Llandudno |
| Postcode | LL41 4DT |
| Country | Wales |
| ITL 1 | TLL Wales |
| ITL 2 | TLL3 North Wales |
| ITL 3 | TLL32 Gwynedd |
| Local authority | Gwynedd |
| Electoral ward | Trawsfynydd |
| Westminster constituency | Dwyfor Meirionnydd |
| Delivery location | TLL Wales |

## Supplier

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

## CPV Codes

### Divisions

- 45 - Construction work

### Codes

- 45000000 - Construction work
- 45111000 - Demolition, site preparation and clearance work
- 45111100 - Demolition work
- 45111200 - Site preparation and clearance work
- 45111300 - Dismantling works
- 45113000 - Siteworks
- 45200000 - Works for complete or part construction and civil engineering work
- 45210000 - Building construction work
- 45262100 - Scaffolding work
- 45262110 - Scaffolding dismantling work
- 45262120 - Scaffolding erection work
- 45262300 - Concrete work
- 45262310 - Reinforced-concrete work
- 45262330 - Concrete repair work
- 45262660 - Asbestos-removal work
- 45500000 - Hire of construction and civil engineering machinery and equipment with operator
- 45510000 - Hire of cranes with operator

## Release History

- 7 Oct 2025 at 14:44 - Award - Award Notice - https://www.contractsfinder.service.gov.uk/Notice/64653164-9879-4b04-8195-949ce6ff8677
- 7 Oct 2025 at 14:43 - Award - Award Notice - https://www.contractsfinder.service.gov.uk/Notice/943f87d4-79ed-4bb5-80d5-226109eec436

## Documents

- https://www.contractsfinder.service.gov.uk/Notice/64653164-9879-4b04-8195-949ce6ff8677
  7th October 2025 - Awarded contract notice on Contracts Finder
- https://www.contractsfinder.service.gov.uk/Notice/943f87d4-79ed-4bb5-80d5-226109eec436
  7th October 2025 - Awarded contract notice on Contracts Finder

## Provenance

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