Structural integrity challenges associated with long term operation of civil nuclear power plant

The UK is entering a new era for civil nuclear power which involves extending the operating life of existing plant, building new plant and designing plant for future fission reactors (Gen IV). The latter two will be required to operate for periods which present challenges for the present materials and methodologies. This paper reviews these potential challenges in the context of the current understanding of materials performance and existing assessment methodologies. In addition, it provides an example of an unexpected creep-related challenge arising from long term operation of Type 316H boiler tubes.