DESARROLLO DE SISTEMAS DE SOLDADURA APLICADOS EN LA VIGILANCIA Y EXTENCION DE VIDA DE VASIJAS EN NUCLEOELECTRICAS

Abstract

In this work three technological developments are shown, which are applied in the surveillance and potential extension of life of the vessels of the Mexican nuclear power plant of “Laguna Verde”, the objective of the surveillance is to evaluate in advance the degree of embrittlement of the vessel over its service life, at present, nuclear power plants can take measures that extend their lifetime from 40 to 60 years. The first two developments are welding systems: The first one is the Welding System for the Reconstitution of Charpy specimens, which reuses halves of previously tested specimens to obtain two reconstituted specimens at least that, these will be reinserted into the reactor, for the surveillance program, potential plant life extension of the vessel and to optimize operating parameters. The second development is the Welding System for Sealed of Containers of Charpy specimens and Tension specimens. These containers that initially were given by the manufacturer of the reactor, they were destroyed to evaluate in the Charpy specimens the embrittlement damage, for what is necessary to manufacture new containers. These containers are inside what is known as capsule surveillance which has between 6 and 8 containers which are of two types, rectangular container for Charpy specimens V and cylindrical containers for tension specimens, the development of this welding system is used to seal the containers with reconstituted specimens which must be filled with ultra–high purity helium at one atmosphere of pressure. The third development is the system for qualification of the welding process used to seal the specimen containers; this system verifies the container pressure, as well as an inspection of the filling gas purity (helium). At the moment these developments have already been used in the surveillance of two capsules and they will be carried out in 2012 a third surveillance, reconstituting the Charpy specimens and sealing the containers pressurized with helium to an atmosphere of pressure, with these reconstituted specimens.