Linking Modularity and Resilience in Infrastructure

Lead Research Organisation: University of Leeds
Department Name: Civil Engineering


A key dilemma in the construction sector is addressing the trade-off of building a certain infrastructure (e.g. a nuclear power plant) as "modular" or "stick built". This research project moves to a new assumption: the design and management of independent physical and organisational modules that, when combined, result in infrastructures (and system of infrastructures) more resilient and sustainable respect to ad-hoc designed monolithic infrastructures. Under this perspective, modularisation is not the "breaking down" of a monolithic infrastructure into ad-hoc modules but "building up" from standard modules designed ex-ante, reconfigurable infrastructures, with embedded resilience to face the uncertainty and dynamism encountered over the plant life-cycle. Considering a given output (e.g. the power plant electrical output), modularization can be defined in three forms: (1.) the creation of a monolithic plant from standard modules (e.g. turbines, pumps); (2.) the creation of a site made of small independent modular plants; and, (3) the installation of small independent modular plants at various sites. This vision deeply modifies the value of plant resilience (that it is possible to quantify with the Real Options approach), and has concrete implications in terms of "modular management".

This project not only considers modularisation in the construction phase, but also in the operations phase; not only from a physical point of view, but also from the organisational one. The development of standard "plant modules" built in mass production would allow efficiently building infrastructures that would also be possible to reconfigure/move/upgrade during their life cycle. As the life cycle of the modules different from the life of the plat/facility a "circular economy" analysis will also be considered.

Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/N509681/1 01/10/2016 30/09/2021
1949429 Studentship EP/N509681/1 01/09/2017 28/02/2021 Benito Mignacca
Description The transition from traditional stick-built construction (a plant constructed in the field without extensive use of modules) to modularisation (factory fabrication, transportation, and installation on site of modules) is a key topic in energy infrastructure in general, and in the nuclear sector in particular with the development of Small "Modular" nuclear Reactors (SMRs).
In the infrastructure sector, two critical variables identified are the reduction of the project cost and schedule determined by the transition from stick-built infrastructure to modularisation. The results of a literature review analysis suggested, on average, a 28.6% construction schedule saving and a 15% capital cost saving. The analysis of the interviews with managers that worked in offshore oil & gas projects in Norway pointed out that the shorter execution time influences the increase in costs since contractors, subcontractors, and suppliers focus on delivering on time. A significant finding is that modularisation reduces in some instances the risk of rework. The results suggested that having smaller modules as units that can be removed or replaced would decrease the high costs of rework and enable cost savings.
However, the transition from stick-built construction to modularisation presents several challenges, e.g. module transportation. The analysis of the interviews with experts in heavy-lifting and transporting modular projects showed that several relevant permits and procedures must be prepared before transport, respecting local regulations (e.g. load, size, delivery time, storage area). Communication during the design phase, communication during transport, special equipment, accessibility and equipment availability of the final location of the modules are the main enabling factors. Incidents and obstructions, module lifting, load and dimensions of the modules, and the weather conditions are the main challenges of module transportation.
Several takeaways for the specific case of SMRs have been identified from the previous interviews with experts and analysis of the literature. For instance, a key result of the research reveals the actual importance of vendor selection, for the timely inclusion of modules, interface information and freezing critical modular parameters. Another key takeaway identified is the division of the responsibilities between the module transportation company and the client.
A systematic literature review focusing on the economic and finance of SMRs suggested that SMR investment can be attractive in some scenarios, and there is a gap in knowledge about the cost-benefit analysis of the modularisation and SMR decommissioning. Furthermore, a novel and under-researched area in energy infrastructure in general (SMRs particular) is the link between modularisation and circular economy (shifting from a system in which resources are extracted, turned into products and finally discarded towards one in which resources are maintained at their highest value possible), which could improve the sustainability of energy infrastructure in general (SMRs in particular). The key idea of this approach (i.e. Modular CE) is that modular infrastructure could be made reconfigurable and extend/adapt their lifecycle by decoupling the life of the infrastructure from their modules. Modules can be designed in a way that, when a module reaches its end of life, it could be exchanged extending the life of the infrastructure. Furthermore, when the infrastructure needs to be retired, modules that are still functioning could be used in other infrastructure. In this way, the residual lifetime of certain modules with a longer life is not wasted. Modular CE has not been investigated in energy infrastructure.
Leveraging the results of a systematic literature review focusing on "Modular CE" in the case of modular product and modular building and discussions with experts in circular economy, the drivers (e.g. addressing the United Nation Sustainable Development Goals), enabling factors (e.g. market for second-hand modules), challenges (e.g. design and interface standardisation), advantages (e.g. reduction of construction and demolition waste), disadvantages (e.g. higher complexity) of Modular CE have been identified. Furthermore, leveraging a case study analysis and discussions with experts in modular projects, the drivers (e.g. environmental conditions), enabling factors (availability of technology for lifting and transportation), challenges (licensing and regulation), advantages (increased productivity), and disadvantages (e.g. supply chain start-up cost) of modularisation have been identified. Finally, "modularisation" and "modular CE" have been compared highlighting that Modular CE retains (in addition to its own) drivers, enabling factors, challenges, advantages, and disadvantages of modularisation. Furthermore, policies fostering "Modular CE", such as working toward standardisation, have been presented.
Exploitation Route The final outcome of this research project is to provide a set of guidelines for the initiation and delivery of modular energy infrastructure (with a particular focus on nuclear and oil & gas sectors) considering the link between modularisation and circular economy (i.e. Modular CE). As summarised in the previous section, Modular CE could dramatically change the life-cycle of energy infrastructure, improving their sustainability, and allow addressing the Nation Sustainable Development Goals. Therefore, the final outcome of this funding can be relevant and taken forward by policymakers, engineers, construction company, and anyone else is involved in the initiation and delivery of energy infrastructure.
Sectors Construction,Energy