Initial operational results of the first Belgian nuclear power station BR3

The BR3 Nuclear Power Plant, property of the Centre d'éiude de l'énergie nucléaire (CEN), is located at Mol-Donk on the site of the latter, and at a distance of 90 miles as the crow files from Brussels. The operation of the plant is done by an Industrial Group. The reactor went critical, for the first time, on 29 August 1962. The paper gives the results of the preliminary tests and of the first months of operation. The reactor BR3 is of the pressurized, light-water moderated and cooled type, with a nominal thermal power of 90,9 MW . The core is heterogeneous using UO2 fuel, clad with stainless steel and has two regions. The outer region is enriched to 4.43% by weight, the inner one to 3.7 % . Main coolant pressure Is 140 kg/cm2. Different "primary” circuits are in connection with the reactor .
The steam generator has a nominal capacity of 70 t/h . The turbine has two stages and three extraction lines and a nominal power of 11700 kW. The personnel was selected from the experienced personnel of the
conventional power plants and received a thorough training in both the nuclear and the classical field.
The paper gives the results of the practical determination of the plant characteristics: control-rod worth and boron worth determination, calibration of the control rods, temperature and pressure coefficients determination, determination of the dropping time of die control rods, etc.
The excess reactivity was calculated for the clean core. These tests were done at zero power and after 441 effective full power hours (EFPH)burn-up: 750 MWJ). A résumé is given of the load transient tests and the power coëfficiënt determination. Different problems encountered during operation are treated:
Radiation activity in the plant: we may conclude from the results that the habitual work in the normal areas is not affected by the radiation intensities present. Activity in the air of the building: the only problem which appeared «mtil now is the presence of radon in the reactor building and in certain auxiliary buildings. This radon comes from the concrete. Leak-rate of primary water: about 100 1/h. Mechanical difficulties, e.g. with the charging pumps, untightness of valves, etc.