Published date: 7 October 2025

This notice was replaced on 7 October 2025

This notice does not contain the most up-to-date information about this procurement. The most recent notice is:

Awarded contract (published 7 October 2025)

Awarded contract - This means that the contract has been awarded to a supplier.


Contract summary

Industry

  • Construction work - 45000000

  • Demolition, site preparation and clearance work - 45111000

  • Demolition work - 45111100

    • Site preparation and clearance work - 45111200

    • Dismantling works - 45111300

    • Siteworks - 45113000

    • Works for complete or part construction and civil engineering work - 45200000

    • Building construction work - 45210000

    • Scaffolding work - 45262100

    • Scaffolding dismantling work - 45262110

    • Scaffolding erection work - 45262120

    • Concrete work - 45262300

    • Reinforced-concrete work - 45262310

    • Concrete repair work - 45262330

    • Asbestos-removal work - 45262660

    • Hire of construction and civil engineering machinery and equipment with operator - 45500000

    • Hire of cranes with operator - 45510000

Location of contract

LL41 4DT

Value of contract

£71,813,292

Procurement reference

CF-0253700D4L000000iAvzUAE

Published date

7 October 2025

Closing date

19 December 2024

Closing time

12pm

Contract start date

6 October 2025

Contract end date

29 March 2029

Contract type

Works

Procedure type

Competitive procedure with negotiation (above threshold)

Anyone may ask to participate, but only those who are pre-selected will be invited to submit initial tenders and to negotiate.

This procedure can be used for procurements above the relevant contract value threshold.

Contract is suitable for SMEs?

No

Contract is suitable for VCSEs?

No

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.

Award information

Awarded date

2 October 2025

Contract start date

6 October 2025

Contract end date

29 March 2029

Total value of contract

£71,813,292

This contract was awarded to 1 supplier.

Costain Limited

Address

Seventh Floor, 70 St Mary Axe, London, United Kingdom, EC3A 8BE, London, EC3A 8BE

Reference

None

Supplier is SME?

No

About the buyer

Contact name

Fiona Pearse

Address

Trawsfynydd Site
Trawsfynydd
LL41 4DT
United Kingdom

Email

fiona.pearse@nrservices.uk