Electricité de France uses Maple to reduce secondary circuit risks in nuclear power plants
Maple, the world leading mathematics software was used by Electricité de France (EDF)’s National Centre of Nuclear Equipment (CNEN) to develop, validate and research a predictive maintenance software program. Maple is developed by Maplesoft, a provider of high performance software tools for engineering, science and mathematics. The EDF software, called BRT-CICERO, is used in the development of inspection programmes for pipe networks in the engine rooms of French nuclear power plants.
Given the availability of the installations and the risks associated with personnel security, EDF developed BRT-CICERO software to optimise control of the pressurized water pipes in the secondary circuit of nuclear reactors. It calculates internal losses of component thickness using the relevant parameters: isometry of piping lines, chromium content of steels, chemical conditioning and thermo-hydraulic parameters within the secondary circuit.
This software, first developed in the early 1990s and updated using Maple, has a prescriptive use in all of EDF’s nuclear sites. It enables identification of the most exposed elements of piping to corrosion-erosion and predicts the point at which their thickness will fall short of the minimal thickness specification. Therefore, BRT-CICERO is an essential tool in managing the risk of corrosion-erosion in piping, and building a shutdown inspection programme. These inspections measure thickness using ultrasound and steel content using portable devices.
The upgraded version of BRT-CICERO was developed by a team of five engineers. They formulated a physico-chemical model, using systems of equations within Maple. The model was then verified by comparing it with the old version of the software. The systems of equations were captured and solved in Maple, and the corresponding C code generated automatically -- directly from the equations.
To satisfy regulatory requirements -- allowing industrial use of the new version of BRT-CICERO software -- a body of technical documents had to accompany the development of the software. This must also pass qualification tests which define its range of use and proves its formula before being used in EDF’s nuclear plants. Maple’s advanced interactive technical documentation function was critical in making this possible. To increase security, the main parts of the test were realized in a range of extreme conditions. More than 14,000 test operations and simulations took place to obtain BRT-CICERO’s qualification.
“We have been very impressed with the speed of Maple’s mathematical computation, its graphical strength and very strong interactive document interface. The automatic code generation, directly from equations, allowed us to automate and considerably speed up development of our validation tools,” commented M. Bouvier, who leads application development. “We now envisage export business for our expertise, as many plant managers have shown a keen interest in the software.”
The integration of predictive maintenance into security procedures has contributed to the fact that there has never been a serious incident in the secondary levels of nuclear plants in France.
Located near Paris, the CNEN (EDF’s national centre for nuclear equipment) is in charge of the design and the development of French nuclear facilities. The centre, which employs 650 people, developed the concept of the third generation of reactors (EPR – European Pressurised Reactor). The CAD Service, which developed BRT-CICERO, involves 54 people who develop professional applications for design and development engineering departments. CAD software for nuclear plants -- with its pre-programmed libraries that integrate mechanical and electrical elements, or software that controls nuclear plants -- is developed here. The CAD Service is a numerical simulation resource that gives engineers with the necessary tools to design and analyse their installations.