The groupe d'analyse nucléaire

The nuclear analysis group (Groupe d'analyse nucléaire, GAN) was created in 1981 by École Polytechnique in order to develop a nuclear analysis capability to support the continued technical requirements of nuclear plant operations at the Gentilly-2 station, owned by Hydro-Québec. These analytical requirements are mostly related to licensing, fuel management and reactor performance analysis. It is important for the operation engineers to fully understand the simulation techniques used in daily activities, as well as their domain of validity. Since its creation, GAN researchers have incorporated a significant portion of their work on advanced analytical methods within computer codes, for computer simulations. For example, the following codes are presently used for nuclear reactor analysis:

DRAGON: this cell and assembly calculation software is used to solve the neutron transport equation using the collision probability or characteristics methods. This code compares favorably with other similar codes used worldwide. It can read different nuclear cross section data libraries. Completely developped at GAN, this code possesses unique features such as 3-D supercell transport calculation capabilities and can use sophisticated leakage models. Furthermore, the code allows the recovery of consistent nuclear properties for reactor calculations with Cartesian or hexagonal lattices. Developped with financial support form NSERC, AECL, Hydro-Québec and École Polytechnique, the DRAGON code is freely available and is used by a number of research orginizations in the world for the study of both power reactors and research reactors.
DONJON: this software is used for finite reactor analysis and relies on the solution of the neutron diffusion equation. One of its module, namely TRIVAC, provides solutions to the diffusion equation using finite element or finite difference techniques. This module has also been implemented in other reactor codes such as HQ-SIMEX (a reactor core simulator used for fuel management calculations at Hydro-Québec). The code DONJON also contains the NDF module that solves the diffusion equation using a nodal approach. DONJON is a natural complement to DRAGON and allows various static calculations for the direct and adjoint flux, for flux harmonics and generalized adjoints. The modules included in DONJON also allow space-time reactor calculations to be performed using the improved and generalized quasistatic approximations.