Year
2010
File Attachment
Abstract
AREVA-TN International works in collaboration with nuclear industry operators to manage the transportation of fuel assemblies in casks. In order to optimize the management and evacuation of spent fuel from nuclear power plants, AREVA-TN International developed the “Transportabilité” calculation tool. The aim of such a tool is to quickly determine the dose equivalent rates and thermal powers for a chosen fuel batch in the suitable cask among those available, and to check whether the transportation is possible according to the regulatory criteria. For each type of cask used, a calculation model is associated in the tool. The addition of a new model in “Transportabilité” is systematically carried out with a three-step methodology. First, the cask to be implanted is modelled and dose rate calculations are made using a three-dimensional Monte Carlo code. Then, three dose rate measurement experiments are done around the loaded cask. Finally, the model created in step 1 is tuned according to the experimental measurements while taking into account margins in order to cover uncertainties associated with the statistical calculations and the measurement instruments. The increase of PWR MOX (Mixed OXide) fuel use in nuclear power plants during the last decade has led TN International to design a new cask called the TN®112. This cask will allow the loading of 12 MOX spent fuel assemblies per transport, which offers an economic interest for both operator and our firm. Consequently, a new model has been added in “Transportabilité” to continue optimizing the management of spent fuel, and particularly MOX fuel. The goal of this article is to present the three-step methodology used for the TN®112 cask, notably the calculation procedure with evolution codes ORIGEN and DARWIN and the 3D Monte Carlo code TRIPOLI-4.3. This article also deals with the global benchmark done around the cask and the comparisons between measured and calculated dose rates.