Embrittlement of nuclear reactor pressure vessels

Abstract

Neutron irradiation embrittlement could limit the service life of some of the reactorpressure vessels in existing commercial nuclear-power plants. Improved understanding the of the underlying causes of embrittlement has provided regulators and power-plant operators better estimates of vessel-operating margins. This article presents an overview of embrittlement, emphasizing the status of mechanistic understanding and models, and their role in increasing the reliability of vessel-integrity assessments. Finally, a number of outstanding issues and significant opportunities, including a new fracture-toughness master-curve method, are briefly described.

Influence of interface sink strength on the reduction of radiation-induced defect concentrations and fluxes in materials with large interface area per unit volume

“…"Radiation damage of materials," however, does not refer to a single problem. Rather, it is an umbrella term for a host of degradation modes, such as swelling [2], hardening [3,4], and embrittlement [5]. Further, mitigating one mode may exacerbate another.…”

Ternary Fe–Cu–Ni many-body potential to model reactor pressure vessel steels: First validation by simulated thermal annealing

“…The formation of these different types of precipitates may be at least partly radiation-induced, but no consensus exists about their actual origin, nature and mechanism of formation. There is, however, consensus about the fact that the interaction of these nano-defects with dislocations is the main cause of hardening and embrittlement of these steels [7][8][9][10][11][12][13][14][15][16]. In this framework, large scale atomistic simulations in multi-component alloys are of fundamental importance with a view to cast some light on the mechanisms leading to the formation of the mentioned different classes of precipitates, as well as in order to study in detail their interaction with dislocations as source of hardening.…”

“…The choice of the Fe-Cu-Ni alloy as first step towards the development of potentials for multi-component systems was dictated by the fact that these two alloying elements are phenomenologically considered to be the main responsibles for RPV steel hardening and embrittlement [13,23].…”

Vacancy enhanced formation and phase transition of Cu-rich precipitates in α - iron under neutron irradiation

“…[1][2][3][4][5] Thus, the evolution of these nanometer-sized Cu-rich precipitates must be considered in hardening and embrittlement models for lifetime predictions of RPV steels. 6 Radiation-induced Cu precipitation in steels and alloys has been extensively studied by experimental methods. [7][8][9][10][11] These experiments have identified three phase transition stages of Cu-rich precipitates: 1) Cu-rich precipitates nucleate in the body-centered cubic (bcc) structure; 2) as they grow, the precipitates undergo a martensitic phase transition, from bcc structure to a multiplied twinned 9R structure; 3) they finally transform into the face-centered cubic (fcc) structure.…”