The international nuclear industry, similar to other sectors of energy and also infrastructure, approaches and uses building information modelling (BIM) in different ways and intensities to support efforts to improve project development, operations and overall asset management over the long-term. Yet it is still early days for the adoption and use of BIM – in all sectors.
Potential uses of BIM in the nuclear sector range from possible new build projects (both large plants and also small modular reactors (SMRs)) to waste management to help boost efficiency through the full lifecycle of an asset.
Among the many key players active with BIM in the nuclear sector at present are Finnish nuclear waste management company Posiva as it develops what is set to be the world’s first Final Disposal facility for spent nuclear fuel; and, its retained major consultant Sweco, which is providing BIM and other services to the pioneering geological repository and encapsulation plant project.
Also of note is UK-based firm Waldeck Consulting, which is active with BIM in a number of areas globally, including discussions on SMRs and assisting with the UK nuclear industry’s journey towards greater engagement with BIM (see adjacent text box).
Posiva & BIM
Juha Matikainen, unit manager for structural engineering and rock engineering with Posiva, explains that the nuclear waste management company’s use of BIM is focused on its current major construction initiative – the Final Disposal project, located on the island of Olkiluoto on the west coast of the country.
With the construction licence approved a year ago, design work at a very advanced stage for the surface buildings and deep access tunnels already constructed to the mostly underground future disposal tunnels, the project is set to be the first in the world and is leading the way ahead on delivering on final disposal.
Matikainen notes, too, that as part of its many collaborations with Swedish Nuclear Fuel and Waste Management Co (SKB), the companies also have information exchange on uses of BIM. SKB is developing its own final disposal facility.
“We have one project which includes an above ground encapsulation plant and the repository inside the bedrock,” says Matikainen. “BIM is also used in the already built ONKALO part” – the rock characterisation facility.
Matikainen adds, though, that while consultant Sweco ‘is our BIM supplier’ the BIM work is ‘only one part of the civil design scope’ of services on the project.
Posiva’s key BIM manager on the Final Disposal project is Antti Hämäläinen from Sweco. He is a BIM specialist and typically covers activities such as quality assurance, managing BIM models, generating virtual reality (VR) documents and undertaking consultancy work on BIM.
On the Final Disposal project, Hämäläinen is working as main BIM coordinator for Posiva.
Posiva – Final Disposal Project
Posiva is jointly owned by power companies TVO and Fortum, and is charged with establishing the Final Disposal project which is currently expected to be operational – the first in the world – by 2020s, and then be used for about 100 years.
Then, after closure of the repository, all responsibilities for the filled and sealed off system – with canisters buried in individual silos, or deposition holes, at the ends of networks of carefully excavated and then backfilled tunnels – is handed over to the state of Finland.
Everything on the surface will have been dismantled and no access will be possible to the deposition depths below the restored site – “one of the principles of this concept” of final disposal, NEI has been told by Posiva corporate adviser Erkki Palonen.
On that basis, the possibility of having a thoroughly detailed and accurate virtual model – via BIM – holding all data generated over the planning, development and operational lifetime of the site is important.
The spiralling access tunnel already has been excavated to the disposal horizon, at depths of 400m-450m below sea level. A central underground access zone will function as “pit bottom” from which long central tunnels will run, and then branching off each will be the local deposition tunnels. Only a few local tunnels will ever be open at a time. Throughout the life of the facility there will be a repeated, local three-step process of excavate, disposal and backfill.
Each local disposal tunnel up to about 350m long is to hold about 30 bored deposition holes, spaced at about 10m centres. Each of the 1.75m diameter holes will hold a copper canister, sealed off according to the KBS-3 engineered barrier system. The facility is licensed to take 6500 uranium tonnes, equivalent to about 3250 of the copper storage canisters, placed at about 20-40 canisters annually – although the Encapsulation Plant on the surface, which prepares the canisters, has been designed with higher capacity.
In late 2015 the company received the Construction Licence for the project, enable the works to advance further on a number of fronts – including preparation for the Encapsulation Plant which is expected to start construction works in 2019. Excavation of the first parts of disposal facility will be started at the end of this year and for the first disposal tunnels is anticipated to commence around 2019-20.
Posiva – BIM contribution
With complex surface and underground structures and arrangements, the Final Disposal projects has large volumes of information and data being generated and needs to be optimised, and held. BIM plays a key role in pulling together the arrays of data and holding it all together in an assembled digital model.
‘The BIM design tools are used by all design parties – for both the above ground and the underground parts of the project,’ says Hämäläinen. “This wide use of BIM has been required at the top-level in the project,” – architecture; structural design; mechanical, electrical and plant; and rock engineering.
These areas of engineering in the project are providing their data in a common format – IFC – to effectively work together as an assembly, a combined digital model. The software system holding the models and data is provided by Finland-headquartered software company Solibri.
Solibri notes that while BIM brings efficiency benefits to the development phase, and over the long-term for owners with vision for asset management beyond construction completion, it is “not a technology”. Rather, it explains, is an approach to sharing data and coordinating digitally and requires technologies to make this all happen.
Different suppliers have different software systems in the BIM services sector, and also data sharing formats can vary too – such as the plain-text files of IFC (Industry Foundation Classes) which emerged from building SMART (earlier termed IAI).
Solibri adds: “Modern BIM systems are able to create rich internal representations on building components. IFC adds a common language for transferring that information between different BIM applications while maintaining the meaning of different pieces of information in the transfer.”
The benefits coming from the approach include: reducing the need for remodelling – i.e. not having parties trying to build their subtly different (or more) versions of the same structure or element as a model; boosting the transparency of the process, which Solibri says also includes benefits to developing the project economics by being able to take off quantities at any time and stage of the design to help evolution of cost estimates.
Hämäläinen explains that all underground excavated rock surfaces are laser scanned to create point clouds of data. Point cloud data are converted to optimised surface models, which can be used in any BIM software and they are included in the combined BIM model.
“By using IFC as a file format between design softwares,” he says, “we will maintain the crucial information which is contained in the model.”
The combined BIM model – the combination of all data from different disciplines, gathered and held in an interlinked assembly of models – is an important tool for communication and visualisation during meetings, says Hämäläinen.
In addition, he adds, the network of relatable information supports highly effective quality assurance work, including both visual and software clash checking. Solibri itself says its tools in effect “x-ray” BIM models, offering 3D visualisation and walk-in functionality “to reveal potential clashes flaws and weaknesses”.
“The BIM model is also used for virtual reality models,” says Hämäläinen. The end result of the project has been experienced by using VR glasses. Development is still ongoing in the VR world for the project, and new useful VR tools will be implemented during the design phase.
But they are more than simple 3D objects: e.g. these underground surfaces – like any above-ground structural
or building element – are also full of relevant additional information. The extra information and data can provide useful key details for future benefit in operating the overall asset, such as informing planning decisions related to facilities management, etc, explains Hämäläinen.
Comparing the Final Disposal project work with other activities in the international infrastructure and energy sectors, Hämäläinen says: “In general, these Posiva projects are very detailed with a high accuracy level and every design discipline has created a BIM model if you compare projects to traditional industry projects.” Matikainen comments that he feels Posiva’s efforts with BIM is giving it a leading role through application and experience.
Looking at the progress of IT and digital technology in service of infrastructure and energy sector projects, Hämäläinen considers BIM to be “mainly the ‘standard’ way of working for us.”
“Although we are doing BIM all the time there is still a role for 2D drawings,” he says. They are “still useful and handy views from BIM models,” and they do not have to be paper but can be available on tablets, smartphones and augmented reality (AR) glasses such as Hololens.
There is still “huge potential in BIM” in areas that have yet to be implemented widely, says Hämäläinen. Key tools within the BIM and digital environments that he says could see greater application include VR, AR, real-time communication and also IoT (Internet of Things).
“They are coming more in use,” says Hämäläinen, “and we are pushing that”.
