Maintenance of RPV-Internals Barrel bolt and baffle bolt replacement with Mast System

Having been developed in on-site applications for more than 20 years the current New Mast System by AREVA represents a very flexible and reliable repair and replacement system for any type of core internals in PWR and BWR type nuclear power plants. Since its first application in 1985, AREVA has significantly enhanced the existing mast system principle for repair issues and the replacement of baffle and barrel bolts. The modular design of the New Mast System makes it easily adaptable for repair, replacement, inspection, and sampling tasks on any type of core internals of all major plant manufacturers. The New Mast System consists of a mast manipulator and the task-specific tooling units. The considerably increased stability of the mast manipulator compared to the previously applied mast systems is only one of many developments. Basic requirements for the New Mast System feature high efficiency, high positioning accuracy, high precision repositioning at the same working location after tool exchange and the feasibility to repair all kinds of bolt damages in a safe and efficient manner. Since 2006, the New Mast System has been applied very successfully in several European nuclear power plants and has continuously been improved.