Project Update – June 2025

Welcome to the June edition of the Sizewell C update on project progress.  

Key updates about works on each site can be found below. It is worth noting that enforcement of the 30mph speed limit by average speed cameras average speed zone on the B1122 and B1125 will start in July.

This month, the UK Government gave the go-ahead for Sizewell C. This is the first British-owned nuclear power station to be announced in over three decades, with HMG as a majority shareholder alongside EDF.  For further details on the announcement click here: Green Light for Sizewell C – The First Majority British-Owned Nuclear Power Plant in Over 30 Years - Sizewell C

Last month, Sizewell C announced plans to build a new post-16 college for its host town in Suffolk – a move that could transform higher education access in the area and ensure a long-term skills legacy for the region. The Further Education (FE) college will be delivered in partnership with Suffolk New College and will be an extension of their current local provision, known as ‘On the Coast’. It will be a permanent high-quality post-16 education facility for Leiston, which will deliver comprehensive, multi-site education and training.  Further details regarding location and planning requirements will be outlined shortly. For further information click here: Sizewell C to build new post-16 college for host town in Suffolk - Sizewell C

These monthly updates are now available on subscription, if you would like to further subscribe, please create an account via the Sizewell C works tracker at www.szcworkstracker.co.uk/my-account/

Main Development Site

Work on the Temporary Construction Area continues with the completion of acoustic fencing to mitigate impacts on local wildlife. Preparation for the construction of the desalination plant is progressing as well as the construction of the northern haul road which is required to move materials around our site during the main civil works on the Main Construction Area. This route requires the bridge over the Site of Special Scientific Interest to be constructed which is well under way. Works to the northern side of the bridge include finishing the installation of the sheet piles which act as an environmental barrier, and on the southern side of the bridge works are underway to begin installing the sheet piles.

Works on the Main Construction Area also include preparing compounds for installation of the desalination plant water shaft.

On the Ancillary Construction Area off King George’s Avenue in Leiston we are progressing well with earthworks. We have taken delivery of some ballast and pre-assembled track sections in preparation for the construction of our rail head, with the switch and control units, also known as points, already constructed and in storage off-site ready to be delivered when required.

Sizewell Beach and Harbour Area

Construction of the northern section of the temporary sea defence has started with the first sheet piles being installed. The works will take place within the Sizewell C fence line and the public footpath will remain open. We apologise for any noise disturbance which we will endeavour to keep to a minimum.
Works will soon commence on installing a temporary outfall on the beach. This work will be a short duration and within a fenced compound.
Our obligations as a Statutory Harbour Authority require us to publish General Directions which detail the restrictions applicable to operating the harbour area. These have been consulted on and implemented. They include the harbour area boundary and how the public will be informed of activities in the harbour. To support this, notices and signs will be installed at the Sizewell Beach car park.

In and around Leiston

The site where the plaza roundabout will be constructed is being prepared for construction. The roundabout will connect the main entrance to Sizewell C with the B1122 / Abbey Road and Eastbridge Road. We are removing roots from previous vegetation clearance and have started to divert utilities to enable construction to take place. The roundabout will be completed in early 2026.

We will shortly start work on the new junction of Lover’s Lane and Abbey Road as part of the realignment work to allow us to install a new level crossing for our Green Rail Route.

Community Road Improvements
We have installed average speed cameras along the B1122 and B1125 to enhance road safety in the new 30mph speed limit. On the B1122 the average speed cameras are in operation between Yoxford and Leiston, and the B1125 speed cameras are between the B1122 junction and Westleton.

The temporary A-frame signage for Sizewell C along the A14, A12 and local roads is being upgraded to permanent signs mounted on posts.

The layby on the northern carriageway of the A12 near to the B1078 will be upgraded to accommodate our Abnormal Indivisible Loads later in 2025. This is needed to manage our wide load HGVs that are escorted by the police.

In Autumn 2026 we will start road improvements along the B1122 and B1078, along with the B1078/A140 and B1119/A12 junctions. Further details and updates will be given to communities as the works programmes are finalised.

Leiston Airfield
The new compound at Leiston Airfield is nearly complete. This will allow our teams delivering rail improvements to move from the current Buckleswood Road compound, which will then only be used for material storage.

Community Road Improvements
We have installed average speed cameras along the B1122 and B1125 to enhance road safety in the new 30mph speed limit. On the B1122 the average speed cameras are in operation between Yoxford and Leiston, and the B1125 speed cameras are between the B1122 junction and Westleton.

The temporary A-frame signage for Sizewell C along the A14, A12 and local roads is being upgraded to permanent signs mounted on posts.
The layby on the northern carriageway of the A12 near to the B1078 will be upgraded to accommodate our Abnormal Indivisible Loads later in 2025. This is needed to manage our wide load HGVs that are escorted by the police.

In Autumn 2026 we will start road improvements along the B1122 and B1078, along with the B1078/A140 and B1119/A12 junctions. Further details and updates will be given to communities as the works programmes are finalised.

Leiston Airfield
The new compound at Leiston Airfield is nearly complete. This will allow our teams delivering rail improvements to move from the current Buckleswood Road compound, which will then only be used for material storage.

Off-Site Infrastructure

Two Village Bypass
We have started installing welfare facilities for our team at the Friday Street Roundabout compound ahead of main works starting later in the summer. We have completed all vegetation removal at this site apart from one oak tree which will be removed and used in local community projects. All the site accesses have now been established, and construction will begin once our archaeological surveys are complete.
From 26 June, a 30mph speed limit will be implemented along the A12 alongside the Friday Street site construction advisory signage has also been put in place.

Sizewell Link Road
All the site accesses required for the construction of the Sizewell Link Road have now been completed. Archaeology and ecology works continue across the sites, and main construction will begin in a phased manner once this work has completed.

Yoxford Roundabout
Construction of Yoxford Roundabout will begin in early July with earthworks to bring the level of the site close to the current level of the A12. During this phase we will transport surplus material to our site on the A12 which will be used for the construction of the Sizewell Link Road. The roundabout will be completed in early 2026, with the majority of work taking place offline before the final connections to the A12 are made.
 

Park and Rides

Northern Park and Ride, Darsham
Site preparation, including construction compounds and welfare facilities, ecology and archaeology mitigations, continues at our Northern Park and Ride in Darsham. Construction of the roundabout next to the A12 and Willow Marsh Lane has started. To aid road safety for all road users a 30 mph speed limit on the A12 is planned between the A144 and the Darsham level crossing, supplemented by traffic management schemes which are under development.

Southern Park and Ride, Wickham Market
Our archaeologists continue their work on our site in Wickham Market which will conclude this summer. As areas become clear of archaeology work, construction will begin in a phased manner from the summer.
For information: the current works along the A12 slip road and B1116 is being carried out by Cadent gas who have put in place an emergency closure and diversion route along the A12 Hacheston Northbound Slip Road only. These works are not associated with Sizewell C, for more information click here: Causeway one.network

 Orwell Logistics Park and Freight Management Facility
The Freight Management Facility, located within Orwell Logistics Park, is now operational. It’s a vital part of how we will manage our lorries travelling to the main construction site. HGVs will check in to the facility and be security checked before proceeding along one of the approved routes to our sites.

Orwell Logistics Park also has office space for the project. This enables us to distribute the workforce across the region. The first team that was previously based at the Ancillary Construction Area Project Office in Leiston has now started to work from this office.

Rail Works
From the week commencing 7th July, track works will start along the Leiston branch line. Work will include lifting and removing of old track and ballast. Once this phase is complete, there will new track and ballast laying.

The works will be carried out by engineering trains and specialist tracklaying plant including along the track, initially in the section to the west of Leiston, which is away from main residential areas. Click here for example of the machinery that will be used. The work can be noisy and create dust, however we will have dust suppression in place to minimise the impact. Working hours will be from approximately 0700 – 1900.

The Leiston air field compound that will provide workers facilities and parking will become fully operational from 7th July, leaving the Buckleswood compound for logistics only. This will alleviate pressure on Buckleswood Road and Westward Ho. We are working with SCC to add advisory traffic signage on Westward Ho to advise no Sizewell C related vehicles movements.

The East Suffolk Branch Line, which runs between Ipswich and Lowestoft, is also undergoing improvements. Earlier this year we completed level crossing improvements and track upgrades. Surveys will take place at Darsham and Melton stations ahead of improvement works starting in 2026. Network Rail will also be delivering upgrades to other level crossings on the East Suffolk Branch Line later in 2025.

 Forum Schedule
Our forums and working groups are a way for local people to hear about key issues related to the construction of Sizewell C. All forums run from 18:30 to 20:30 (arrival from 18:00).

All meeting papers and presentations can be accessed on our website Community Forums - Sizewell C. If you have any questions or would like further information, please do not hesitate to contact us. We are available in person at the Information Office on the High Street in Leiston (Monday to Friday, 09:30 to 17:00), via the 24-hour helpline on 0800 197 6102 or by email info@sizewellc.com.