Operating life extension: new insights into reactor vessel steel ageing

Speakers: Lorenzo Stefanini & Murthy Kolluri (NRG)

Language used during webinar: English

Introduction:

Operating life extension is defined as safety assessment for plants that are operated beyond their original design life. Because conservative design allows many nuclear power plants to operate longer than envisaged at construction, knowledge about ageing phenomena is becoming increasingly important. For most nuclear power plants, the original design life was 40 years. Currently, the design life of many plants is being adjusted to 60 years of operation and some even to 80 years, with proof of safe operation provided by LTO projects.


Within NRG's research programme, an important place has been given to the so-called Time Limited Ageing Analyses (TLAA), the analyses that determine the plant's design life. Knowledge of these determines the analysis method, conservatisms and ultimately the physical design life of the power plant. The presentation will zoom in on one such TLAA, namely reactor vessel steel (RPV) and, more specifically, the question of what are the effects of long-term exposure to neutron radiation on the mechanical properties of the RPV.

The presentation will present the results of a combined mechanical-microstructural study of a unique set of RPV samples as well as the findings of ageing control studies using the Pressurised Thermal Shock (PTS) scenario.

Participation is free of charge. Register via the KIVI website. The link for participation will be sent upon registration.

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