Mechanical stability paradigm for prediction of rpv service life

TL;DR

This paper introduces a new paradigm for predicting the service life of reactor pressure vessels based on mechanical stability, linking ductile state stability to critical fluence and demonstrating its application on WWER-1000 vessels.

Contribution

It proposes a novel life-time prediction method using mechanical stability exhaustion, grounded in fracture mechanics and applied to nuclear reactor vessels.

Findings

Mechanical stability level influences critical fluence.

The new paradigm accurately predicts vessel end-of-life.

Method demonstrated on WWER-1000 pressure vessels.

Abstract

In the framework of the engineering version of a Local approach to fracture the criterion of a fracture limit of RPV with crack-like flaw is derived. It has been shown that the level of ductile state stability (mechanical stability) of metal ahead of a crack governs the value of critical fluence. On this basis, the new paradigm of life-time prediction using the condition of exhaustion of mechanical stability of irradiated PV metal has been proposed. The technique of an end-of-life fluence assessment is developed, and predictive capabilities of this approach are demonstrated by the example of WWER-1000 pressure vessels