Kalinin NPP: System for inside erosion-corrosion monitoring
Kalinin NPP: System for inside erosion-corrosion monitoring
Description
Background
Carbon steel piping and components of the secondary circuit of VVER reactor power plants are affected by the erosion corrosion process. The erosion corrosion process results in wall thinning of piping during operation of the plant. Wall thinning of pressurized piping and components if not detected leads to pipe rupture, plant shut down and the possibility of fatal accidents involving the operation personnel working close to the affected pipe/component.
The erosion corrosion process is influenced by a large number of parameters like flow velocity, fluid temperature, water chemistry parameters such as oxygen concentration and pH, material composition and piping geometry. The complexity of their functional interdependencies and the large effort involved in analysis of entire piping systems in power plants requires besides the weak point analysis also measurement of the remaining wall thickness.
Objectives
The subject of this supply contract was to provide Kalinin NPP with measurement equipment to monitor the erosion corrosion in secondary circuit piping systems. The supplies included the delivery of 3 ultrasonic thickness measurement equipment, 2 ultrasonic flaw detectors and necessary set of 14 ultrasonic probes, 1 personal computer, as well as software for the automatic transfer of the measurement data from the ultrasonic equipment to the computer for further analysis. The supply also included the supply of the technical and operational documents and provided training to the End user personnel in the use of the supplied equipment.
Project Results
The equipment and services were provided in accordance with the contract requirements in 2001. The Final Acceptance Certificate has been signed on November 26, 2002.
The supply of the ultrasonic equipment allowed the plant to implement an erosion corrosion monitoring program predicting the integrity and lifecycle of the piping. By replacing of thinned piping in time increase significantly the personnel safety as well as the safety and reliability of the plant.