Electricité de France uses Maple to reduce secondary circuit risks in nuclear power plants - User Case Studies - Maplesoft

User Case Study: Electricité de France uses Maple to reduce secondary circuit risks in nuclear power plants

Maple™, the world-leading mathematics software, was used by the National Center of Nuclear Equipment (CNEN) of Electricité de France (EDF) 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 to develop inspection programs for pipe networks in the engine rooms of French nuclear power plants.

Different types of piping systems
in the engine room

The corrosion-erosion of carbon steel is a general form of corrosion, accelerated by a circulating flow of water or wet steam. It can cause damage to the water-steam networks in nuclear and thermal power plants. Corrosion-erosion leads to a reduction of internal wall thickness. If it is not spotted in time, this issue can lead to leaks or even component failure.

Given the availability of the installations and the risks associated with personnel security, EDF developed BRT-CICERO software to optimize control of the pressurized water pipes in the secondary circuit of nuclear reactors. It calculates internal reduction of pipe wall thickness using 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 elements of piping that are most exposed to corrosion-erosion and predicts the point at which 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 in building a shutdown inspection program. 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 physicochemical 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 was generated automatically, directly from the equations. 

Corrosion-erosion can cause
leaks from pipe bends

To satisfy the regulatory requirements needed to allow industrial use of the new version of BRT-CICERO software, a body of technical documents had to accompany the development of the software. This body of documents also had to pass qualification tests that define its range of use and prove its formula before being used in EDF’s nuclear plants. Maple’s advanced interactive technical documentation features were critical in making this possible. To increase safety, 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 certification

“We have been very impressed with the speed of Maple’s mathematical computation, 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 Mr. Bouvier, who leads application development. “We now envision 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.

About CNEN
Located near Paris, the CNEN is in charge of the design and the development of French nuclear facilities. The center, which employs 650 people, developed the concept of the third generation of reactors (EPR: European Pressurized 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 at that site. The CAD Service is a numerical simulation resource that gives engineers the necessary tools to design and analyze their installations.