KETEP 세계에너지시장정보

A computing means-assisted method to determine an optimal plan for loading a nuclear reactor core, in which method respective positions of nuclear fuel assemblies are tested by said computing means according to at least one criterion before assigning optimal positions to the assemblies and proceeding to load the reactor, the core of the reactor including a plurality of cells having symmetries of positions relative to a plurality of axes of symmetry, common assemblies being intended to be each introduced into a cell, the common assemblies for preparing a future loading being divided into at least three categories defined by the number of production runs of the nuclear reactor: the method being characterised by: - a first category of assemblies that have not been used in a previous production run and having a burn-up below a first threshold, - a second category of assemblies that have been used in a previous production run and having a burn-up between the first threshold and a second threshold, greater than the first threshold, and - a third category of assemblies which have been used in at least two previous production runs and which have a burn-up above the second threshold, the method including the following steps of: - identifying groups of cell positions that are symmetrical with respect to said axes of symmetry, and counting a number of symmetrical positions in each group, - making up families of common assemblies, the common assemblies of a same family having at least similar burn-ups, and said families each including a number of common assemblies corresponding to a number of positions of one of said groups, respectively, - selecting, from a database of valid standard loading plans, a standard loading plan whose burn-ups of assemblies, per family, are closest to the burn-ups of the common assemblies, per family, and, as part of a numerical simulation, assigning to the common assemblies respective initial positions corresponding to the positions of the assemblies in the standard plan selected, - testing by numerical simulation the loading plan made up of the common assemblies at said initial positions, relative to at least one predetermined criterion, - swapping common assembly positions while retaining the assembly families previously made up and testing by numerical simulation the loading plan formed of the common assemblies at said positions swapped, relative to said predetermined criterion, and - repeating the swapping and testing step until at least one candidate plan is obtained for loading the reactor, the candidate plan best meeting said predetermined criterion.