BUILDING EXPERIENCE | SUPPLY CHAIN


Above: Hinkley Point Nuclear Power Station Somerset, UK, is the oroposed construction site of new nuclear power station Hinkley Point C Photo credit: jgolby/Shutterstock.com


the first of the two fully assembled 55m-long cylindrical pressure vessels will be completed in the first quarter of 2023, to be installed internally with four ferritic stainless steel deaerator units, and capped with crown and petal dished ends. Vessco Engineering, accredited with the Fit for Nuclear


Standard (F4N) in 2018 and a member of the Wales Nuclear Forum, specialises in the fabrication of pressure-vessels, heat exchangers, columns and other similar mechanical structures. Recent commissions range from nuclear processing sites such as Sellafield and power generation sites like Hinkley Point C, through to experimental fusion facilities for STEP (Spherical Tokamak for Energy Production). So, what is it about the realm of nuclear engineering


which raises the game for our work in other sectors? Again, it starts and ends with safety. A culture of absolute perfection literally pervades the entire manufacturing process because, bluntly, the scale of potential harm due to error is incalculable. Everything therefore aligns with the regulatory expectations placed on the UK Nuclear Licensees and is shared throughout the nuclear supply chain to support quality improvements. These range from BS EN ISO 9001 and the existing codes and standards within the Nuclear Industry; Office for Nuclear Regulation’s (ONR) Technical Assessment Guides (TAGs), IAEA’s General Safety Guides (GSG) and a host of others. At a practical level this has meant the intensity and


precision of the documentation is much greater than anticipated, and that in no way underestimates the quality systems with which we were already familiar in our work in, say, the oil and gas sector which has its own inherent risks to manage. Nonetheless, and in terms of on-site production processes, the level of scrutiny is also a lot higher. All of this, of course, impacts on time and cost, which is undoubtedly one of the key learnings when it comes to estimating for new projects. In fact, so much investment of time and planning and trialling has been necessary in the fabrication of the first HPC vessel that cost-recovery and margin won’t come through until the closing phases of the second 330-tonne structure. Through this iterative process we have learnt how to


make process improvements, such as how to weld the superstructures better, how to manufacture the dished heads in a different way, how to speed up the fitting and welding of the nozzles, and so on. We have also determined how best we can run different parts of the structure fabrication in parallel, rather than do everything in one long sequence. Given the limited working space within and


around some parts of the vessel structures, though, there’s only so many pairs of hands that safely can be useful at any one time. We have none of the space advantages that one might have, for example, building an aircraft carrier. The vessel has to be rotated in place during manufacturing so we can have the necessary working space to access all of the surfaces, externally and internally. Thereafter, we can manufacture the internals, concurrently with the main vessel, including the saddles, bringing all of the various elements together at the end.


Building knowledge into savings Looking ahead, the time taken earlier for the initial designs, development, and procedural documentation can safely be cut back dramatically. In fact, the whole production cycle should be reducible by up to two-thirds of the original cycle, allowing the procedures to be performed in a more time efficient manner. Going forward, this will enable more cost-effective manufacture. All these are valuable learnings which can feed back


into the nuclear realm for other manufacturers facing similar challenges. In the case of Vessco that includes the water utility industry, chemicals manufacture and the oil and gas sectors. It has, for example, led to us using experiential data on the length of time it takes to manufacture specific structures and components. All of these learnings will be useful across the supply chain. Importantly, however, it can also add value in other market applications. Interestingly, one of the downsides of the nuclear


sector’s rigour is the pace and resistance to incorporate potential learnings from other industries. For example, synergic MIG welding techniques are superbly suited for delivering neat fabrication quickly, but this is not yet approved for use in civil nuclear. In due course, for the right applications that may come. In the meantime, there’s good reason why most of the traffic of learning is one-way. Learning how to prepare for inspection and test plans


and incorporating these well in advance in the organisation of workflow, provisioning for the right welding procedures for each application, building up a library of procedures and techniques for future use, all feed into a compendium of best practice aimed at reducing time and improving quality. Reiterative documented learning in this way eventually reduces 40-days of process down to fifteen whilst improving the quality, and above all the safety, of the end product. What is also clear is that we are not alone; our experience is being mirrored widely elsewhere across the nuclear Tier 2 and Tier 3 supply chain. ■


www.neimagazine.com | December 2022 | 39


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