DOI: 10.1533/9780857097453.3.315

Abstract: This chapter discusses management strategies in terms of mitigation and repair techniques for degradation in pressurized water reactors (PWRs). We begin by introducing PWR materials management strategies followed by details of ageing and life management of the PWR components. International cooperation activities for ageing management are also included. Development and application of mitigation techniques for reactor pressure vessels, reactor internals, steam generators, pressurizer nozzles, control rod drive mechanisms, and secondary piping are described next. Mitigation and repair methods for degradation of PWR components include: material changes, isolation techniques, weld material changes, design changes, weld overlays, stress improvements, environment improvement, mechanical repair and component replacement or removal. Finally, cracking history of components around the world and countermeasures are introduced.

Key words: PWR, life management, reactor pressure vessel, reactor internals, steam generators, pressurizer nozzles, control rod drive mechanisms, primary and secondary pipings.

7.1 Introduction

In the case of PWR power plants, Korea, China and Europe continue to build nuclear power plants which show advanced performance, whereas the [8]