Ageing Management Review (AMR) for LTO

Is your current ageing management sufficient for demonstration of LTO? Long Term Operation (LTO) of nuclear power plants (NPPs) requires a review of the ageing management of all safety relevant structures and components. This AMR is one of the cornerstones of the LTO assessment according to international standards.

NRG has supported Borssele NPP in their Ageing Management Review project as part of the successful LTO licence change of NPP Borssele in the Netherlands. NRG used the lessons learned from this project to support Ringhals in Sweden for their AMR in the framework of LTO.

The AMR methodology is based on the IAEA guidelines and provides a generally and globally accepted concept for LTO assessment. Two examples of LTO projects which have used these guidelines are carried out by NRG. Borssele NPP in The Netherlands used IAEA safety guide 57 “Safe Long Term Operation of Nuclear Power Plants” as a basis for its LTO assessment project. The outcome of the LTO assessment project was submitted to the Dutch regulator for a licence change application to revise the Safety Analysis Report for Long Term Operation until 2034. In 2013, the Dutch regulator approved the licence change. The experience gained in the Borssele LTO assessment project was used to set up the LTO assessment project for Ringhals NPPs in Sweden. Ringhals also adopted IAEA Safety report 57 for the general structure of its LTO project.

As a starting process for the AMR, Scoping and Screening has to be performed. Within the Scoping and Screening processes, all Systems, Structures and Components (SSCs) in the framework of LTO are identified on a component level based on the criteria from IAEA Safety Report No. 57.

In the AMR itself, a detailed technical evaluation of all in-scope passive long-lived components (e.g. main coolant piping) as well as passive subcomponents of active long-lived SCs (e.g. main coolant pump casing) is performed to demonstrate that the effects of ageing are adequately managed such that the intended function(s) will remain consistent with the licensing basis during Long Term Operation.
If applicable, recommendations will be made to improve existing plant programs and/or practices to align the NPP with current nuclear industry. With the fulfilment of the AMR recommendations, the effects of ageing on in-scope SCs are adequately managed (i.e. the intended function(s) will be maintained consistent with the plant’s licensing basis during LTO).