Nozzle penetration for a nuclear reactor pressure vessel closure

摘要

In this type of nozzle penetration, the nozzle (6) consists of a material different than that of the closure (1). In addition, closure (1) is provided with an inside plating. In order to avoid heat stresses on the tension coupling (15) between nozzle (6) and closure (1), a compensating ring (8) is provided between the shoulder (9) of nozzle (6) and contact surface (7) of closure (1). The height "h" of the compensating ring (8) and its material are selected in such a way that the change in elongation resulting from heat expansion of the nozzle and closure materials is compensated in the region of the distance extending from shoulder (9) to tension coupling (15). The material and height "h" can be selected in such a way that a predictable difference in stress is created in the area of the tension coupling upon heating.