Electricité de France and the Commissariat à l’Energie Atomique have developed experimental and theoretical approaches to obtain a better understanding and to provide accurate predictions in the field of circuit contamination. Dose rate and dosimetry measurements made at the Centrale Nucléaires des Ardennes plant confirm data published by the U.S. Nuclear Regulatory Commission and the Electric Power Research Institute for U.S. reactors. From dose and activity measurements and from model predictions, it seems possible that in the near future we will be able to modify some basic design and operation attitudes to reduce the occupational radiation exposure in nuclear plants.