The reactor pressure vessel surveillance program of the Belgian nuclear power plants

This paper presents an overview of the Reactor Pressure Vessel surveillance program as it is applied to the seven Belgian Pressurised Water Reactors (PWR). The first part of the paper recalls the original objectives of the surveillance program, detailing the number of capsules that were installed per reactor, the number that have been retrieved so far and discusses the type of dosimeters installed. The second part is a description of the experimental techniques applied to determine the neutron fluences, a work which is performed in the reactor dosimetry laboratory at SCK CEN and is based on qualified activity measurements. Finally, the paper ends by briefly presenting the calculation scheme developed at Tractebel and by providing a statistical analysis of the C/E values over the ~ 400 in-core dosimeters and 800 ex-core dosimeters that have been analysed to date. The method offers satisfactory results with an average C/E on all dosimeters close to 1.0 and a standard deviation comprised between 8 % and 10 % depending on the dosimeter considered.