[en] This paper presents the first experimental results of the thermal behavior of AECL's CANSTOR spent fuel dry storage module. The CANSTOR module is an air-cooled concrete vault about 22 m long, 8 m wide and 7 m high. It can store 12000 CANDU spent fuel bundles inside 200 baskets which are stacked into two rows of 10 storage cylinders. The first module was built on the site of Hydro-Quebec's Gentilly-2 station during the summer of 1995. Dissipation of the residual heat generated by the spent fuel is a major factor in spent fuel dry storage design and one of the key elements for its licensing. The fuel temperature must be kept below 160 deg C to avoid oxidation. Experiments on a mock-up and calculations showed that the air cooling circuit provides at least 15 deg C margin for the fuel with 6-year cooled fuel subject to the ambient design temperature of 40 deg C. Nevertheless, the Atomic Energy Control Board of Canada (AECB) requested Hydro-Quebec to monitor the temperatures and limit the age of the fuel to more than 8-year cooled. During the construction, fourteen temperature sensors were installed to measure the temperature of the air, concrete and top of storage cylinders. A computer based data acquisition system has been used to collect the data, starting before the first fuel was loaded. The first loading campaign occurred during the fall of 1995, mainly during the months of October and November. The module was half filled with 6000 bundles that had been cooled in the spent fuel bay for more than 8 years, in accordance with the AECB license. No loading was done during the 1995-1996 winter. This provided a few months of data with quasi-constant power dissipation. This paper presents this data and compares it with the calculations used in support of the licensing submission. It is shown that fuel of much less than 8-year cooled could be loaded into the CANSTOR module. (author)