Abstract :
Nuclear reactor containments, especially in the imnediate vicinity of the primary system, are generally not accessible to plant personnel for inspection during reactor operation. Some contaimnent systems are operated with nitrogen enriched atmospheres making personnel entry very difficult, for extended periods of operation. There are three barriers between the fissile materials and fission products in the nuclear fuel and the environment. The first barrier is the fuel cladding, the second is the reactor coolant pressure boundary, and the third is the reactor containment. This paper treats one aspect of the maintenance of the integrity of the reactor coolant pressure boundary - the reactor coolant leakage detection system. In addition, during the plant lifetime the integrity of the primary system is ensured by many safety systems, administrative controls and various surveillance, test and inspection program . This paper discusses an "ideal" leakage detection system, compares it to present systems, and offers a basis for improving present systems to a level closer to the ideal.
