New article published in 12(4B) - ENFIR/INAC 2024

A new methodology to identify Structures, Systems, and Components needed to cope with Design Extended Conditions in the scope of a Nuclear Power Plant Long Term Operation

Abstract: To obtain the License Renewal (LR) for the Long-Term Operation (LTO) of a Nuclear Power Plants (NPPs) is important ensuring the integrity of Structures, Systems, and Components (SSCs). Additionally, the SSCs must continue to perform their intended functions under Design Extended Conditions (DEC). DEC encompasses a wide range of conditions beyond the design basis, including both severe and non-severe scenarios. The ageing process can compromise the intended functions of SSCs in a NPP. NPPs must demonstrate their ability to cope with DEC without compromising safety. The objective of this paper is to describe one methodology have been developed to identify SSCs with scope of LR needed to cope with the DEC in LTO. The proposed methodology follows the recommendation of U.S. Nuclear Regulatory Commission (NRC) requirements and the International Atomic Energy Agency (IAEA) safety standards and demonstrating their commitment to safety and environmental protection. The main contributions of the new methodology is to identify the systems, components and subcomponents needed to cope with design extensions conditions  that not  have Maintenance Program (MP) or Aging Management Program (AMP) and address these components in the plant level AMP or recommend an Aging Managements Review (AMR) according to their characteristic and function. Accomplish the intended safety functions of SSCs throughout the plant's operational lifetime including during LTO is crucial to safety and reliable operation of the plant. An example of application of the proposed methodology is presented. Read full article.