Ageing management in NPP. Effectiveness of the methods for control, examination and monitoring in relation to mechanisms of degradation of mechanical properties

Galya Dimova,V.M Vassilev,Y.P Ivanova,M.D Datcheva,S.G Nikolov

doi:10.1051/matecconf/201814505015

Abstract

This paper describes ageing management activities for Long Term Operation (LTO) of components of Kozloduy NPP EAD. The stages of LTO Project are: Stage 1 - implementing a comprehensive assessment of the actual condition of the equipment; Stage 2 - providing of a Complex Analysis; Stage 3 – licensing of Plant Life Extension (PLEX) for long-term operation (LTO). The main activities are assessment of actual condition of the equipment and building; review of methods for control (non-destructive), examination and monitoring; assessment of effectiveness of methods; necessity of additional control/ examination/ service. The paper describes some mechanisms of degradation of mechanical properties, methods for control and criterions for their effectiveness.

Highlights

Many nuclear power plants (NPPs) around the world have been operating for over 30 years
The possibilities for plant life extension (PLEX) of nuclear power plants are demonstrated through analyses, tests and lifetime management for the expected long-term operation (LTO)
The subject of this paper concerns lifetime management and plant life extension of the NPP power units. It arises from the implementation of forthcoming PLEX activities on units 5 and 6 at Kozloduy NPP (KNPP)

Summary

Introduction

Many nuclear power plants (NPPs) around the world have been operating for over 30 years. The operating design life of Nuclear Power Plants (NPPs) is normally 30-40 years, [1]. The possibilities for plant life extension (PLEX) of nuclear power plants are demonstrated through analyses, tests and lifetime management for the expected long-term operation (LTO). The subject of this paper concerns lifetime management and plant life extension of the NPP power units. It arises from the implementation of forthcoming PLEX activities on units 5 and 6 at Kozloduy NPP (KNPP). Since 2010, the plant has undertaken a large-scale PLEX project for comprehensive assessment of equipment and lifetime extension of the power units 5 and 6, [2]. The PLEX project has been subdivided in the following stages: Stage 1 – performing of a comprehensive assessment of the current condition of equipment and buildings (ageing management review) (2010-2013), [3]

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Methods

Conclusion