The Hinkley Point C nuclear project has made significant progress since construction officially started on site in October 2016. By the end of 2017, 64 major contracts had been awarded worth nearly £9bn, with 64% of the construction value going to UK businesses. The earthworks and enabling works are well progressed allowing the main civil works to ramp up during 2018.
The consortium developing the HPC nuclear plant is NNB (Nuclear New Build) Generation Company, a joint venture between the French state-owned company EDF and the state-owned Chinese utility company CGN (China General Nuclear Power Corporation). EDF made their final investment decision in July 2016 and the project was approved by the UK government in September 2016 allowing construction to commence officially on site in October 2016.
You can learn more about the project in our Hinkley Point C Project Profile.
The main civil works are anticipated to start ramping up in 2018. The client NNB have advised that the project remains on schedule to hit its major milestone of the first concrete poured for the reactor building. M&E works on the main power plant are expected to start approximately 4 years into the project and ramp up to a peak in year 6.
The estimated price of construction has risen up from the £18bn quoted in 2016 to £19.6 billion. NNB have indicated that the £1.6bn increase results mainly “from a better understanding of the design adapted to the requirements of the British regulators, the volume and sequencing of work on site and the gradual implementation of supplier contracts”. This has the potential to delay the project for up to 15 months which could incur a further £700m cost increase.
NNB have awarded many of the Tier 1 contracts, who in turn are subcontracting to Tier 2 and 3 companies. Several UK companies have formed Joint Ventures with French suppliers. Major deals to date include the £2bn civils contract for BYLOR, a joint venture between Bouygues TP and Laing O’Rourke, and the £208m earthworks deal won by a Kier and Bam Nuttall joint venture.
NNB advised that they remain on track to meet the 64% UK supply contribution with nearly £9bn of contracts signed to date. In line with these commitments six local consortia have been created to provide a range of services from catering and accommodation, to transportation and facilities management, and the provision of utilities.
A Hinkley Professional Services Group has also been established to provide support to the supply chain in the areas of Human Resources (recruitment, training and employee retention), Legal, Accounting and Finance, Project Management and support to companies who are new to working in the nuclear sector.
You can learn more about the Contractors working on the Hinkley Point C Nuclear Project in our Contractor Profile.
Over 2,400 people were working on the site towards the end of 2017 and this is expected to ramp up to over 3,000 in early 2018. The site teams have over 100 apprentices working on the project, with up to 1,000 apprenticeships expected during the build. At the end of October 2017, an interim pay deal was negotiated with the unions which averted strike action by construction workers.
While there is an intent to optimise off-site works a construction workforce will reach an estimated peak of over 5,600 workers approximately 5 to 6 years into the build, with an intent to reskill and upskill staff employed at the early stages in order to retain them on the project.
Hinkley Point C - aerial view of the North-West of the site showing the jetty and concrete batching plant (image courtesy of EDF)
NNB have been undertaking enabling works on the project since 2008, with a ramping up of staff during 2014 for works that included site clearance and service roads, a bund at the southern site boundary, archaeological investigation, deliveries of aggregates and the commissioning of the main concrete batching plant, which was advised as complete in October 2016. Off-site works included park and ride facilities, construction of bypasses and upgrading of the approach roads.
Since October 2016 construction has focused on bulk earthworks, the 500m long jetty for marine deliveries, construction of the 900m long sea wall, stabilising excavated areas with spray concrete and rock nails, and blinding excavated areas with concrete. Temporary facilities provided include electrical, drainage, sewage and potable water systems, temporary site offices and welfare buildings, and worker accommodation.
The detailed design is progressing alongside the initial construction works with final design works due to be completed before the end of 2018, although the client has advised that detailed design is running on a tight schedule. The design includes a 3D model that has seen the team ‘build’ the project before it reaches site. This is seen as an important construction aid for areas such as the approximately 600,000 bedding plates where the mechanical interfaces with the civil engineering.
September 2017 saw a major Project milestone with the handover of the Pump House foundation raft design studies package. This section of design relates to 3,500m3 of concrete that will be poured over 1,500kg of steel in the 4-5m-thick raft foundation. The Pump House building is the interface between the reactor unit and the cooling seawater. Once the raft is finished, tunnelling work out into the sea can start.
In March 2017 the Office for Nuclear Regulation gave approval for the first Nuclear safety concrete to be poured for a section of the power station galleries, an 8km network of connected tunnels carrying cables and pipes under the plant.
The blinding concrete for the base of the nuclear island unit 1 reactor was poured in August 2017. This is an important step towards construction of the reactor buildings common raft foundations, a milestone termed J0. The first part of the nuclear island to be constructed will be the circular pre-stressing gallery located under the common raft.
Earthworks and initial civil works
Aerial view of the aggregate store and concrete batching plant (image courtesy of EDF)
The earthworks are well progressed with 4 million cubic metres of earth having been excavated. Ground nails, each measuring up to 12 metres long, are used to stabilise the ground with a total of 110km being used during construction. Vacuum excavation has been used in some areas to minimise noise and dust, and reduce the amount of plant movements and manual handling.
Hinkley Point C will comprise of two reactors, the layout of each reactor consists of two major parts: the Nuclear Island and the Conventional Island. The Nuclear Island is at the heart of the nuclear power station. Blinding concrete has been poured for the foundations for the first Nuclear Island.
The reactor buildings include a series of ‘galleries’ which will eventually host site infrastructure, pipes, cables and drainage runs. The first nuclear safety concrete has been successfully poured for these power station galleries. The term ‘nuclear safety concrete’ relates to the consistent production of the concrete to ensure each and every m3 complies with precise requirements laid down by an independent regulator, the Office for Nuclear Regulation. It took three years of rigorous development, testing and refining to get to the point where concrete of the required quality was being produced on a consistent basis. The strictest of quality controls have been put in place, for example to monitor moisture levels in the raw materials to an accuracy within 0.2%.
The first sections of the ‘Circuit de Refroidissement’ (CRF), French for ‘cooling water circuit’, were delivered to site during the summer of 2017. The CRF network will sit below the turbine halls between the pump house and outfall buildings. This pipework will provide the cooling seawater to the reactor building and return the water a few degrees warmer back to the sea. The pipework consists of over 700 pipe segments and will be more than 3km in length when complete. The larger segments are 3.5m wide and weigh nearly 13 tonnes. Socea Denys are the contractor responsible for supplying and installing the cooling water infrastructure and they have been delivering segments from Belgium since June 2017.
The permanent aggregate store has been completed. These facilities will be able to store as much as 57,000 tonnes of aggregate at any one time, including a silo that will store around 5,000 tonnes of ground granulated blast-furnace slag (GGBS). Four concrete batching plants are now operating. Up to 2,000 tonnes of concrete a day can be produced on site.
View of the temporary jetty (image courtesy of EDF)
The Bristol channel has the world’s second largest tidal range, some 13 m, creating challenging conditions for construction of the jetty, the seawall and the works to Combwich Wharf, which will handle delivery of the large loads by sea.
The 500m temporary jetty will allow 80% of the aggregate to be brought in by sea rather than by road, using a conveyor system to unload the bulk materials into the storage silos and bays. Each of the 48 piled foundation legs is 36 metres long, 3.6 metres in diameter and weighs 140 tonnes. Two jack up barge platforms, the Fugro 1200, which is the larger of the two, and the smaller but more specialised, WaveWalker 1, which ‘walks’ through the tidal surf zone at as much as 4 m per hour, are being used to install the piles.
The jetty features a 12 m-wide roadway. The deck of the jetty will be placed using precast concrete sections spanning between the piles and bridge beams. These will weigh in at a maximum of 15.6 tonnes and are set to be manufactured in Taunton before being shipped to the site. Work began on the jetty in summer 2016 and, it is expected to be unloading its first shipments of aggregates by the end of 2018.
Work on the 13.5 metres high, 900 metre long sea wall has to be planned within tidal windows (when the tide is low enough to work on the foreshore). These windows can be as short as six hours. Also, the marine habitat is environmentally sensitive, which means the team has to comply with strict licence conditions. 10,000 tonnes of rock has been delivered by ship from Pembroke, for scour protection in front of the new seawall.
Balfour Beatty were announced as the preferred bidder for the tunnelling works in August 2017, taking over from Costain. There is a manufacturing facility at Avonmouth Docks that will make the 38,000 concrete segments needed for the tunnels, at a rate of 600 a week, requiring 83,000m3 of concrete and cast the six massive outfall and intake heads. There are two intake tunnels, 6m in diameter and 3.5km long. One outfall tunnel, 7m in diameter and 1.85km long. There are two heads weighing more than 5,000 tonnes on each intake tunnel and two 2,500-tonne heads on the outfall tunnel.
Thought to be the largest hotel-style development in Europe for 25 years, the accommodation will provide around 1,500 en-suite bedrooms in 44 buildings across two locations. The Bridgwater Campus is the larger of the two developments with 1,000 beds, is being built in three phases on the site of a former Cellophane factory, while a 500 bed development is being built on the actual construction site.
The room modules are being manufactured off site and are delivered 96% complete, with all en-suite rooms fully fitted out, complete with carpet and even mattresses on the beds. Using prefabricated units has halved the installation time compared with traditional build, as well as reducing the environmental impact of onsite construction and lowering the demand for skilled trades in the area.
Construction of the on-site accommodation is expected to finish in April, while the Bridgwater campus is expected to be operational later in 2018.
A2O People produce a regular series of blogs designed to keep people informed about the Construction Industry, the UK Energy Sector, the UK Nuclear Sector, the Hinkley Point C project, and HR / Employment Law issues impacting the Construction sector.
Shane Keaney is a director of A2O People a Recruitment and People Consultancy specialising in the Nuclear and Energy Construction sectors. You can learn more about our Recruitment, Business Advisory and Training services on our website www.a2opeople.co.uk, by emailing us at firstname.lastname@example.org or calling 01278 732073.
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A2O People are a member of the Hinkley Point C Professional Services Group. We have developed a Guide for Job Seekers for people interested in working in the UK nuclear sector and a Supply Chain Guide e-book for companies interested in working on the UK Nuclear New Build projects.
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