Impact assessment in the UK nuclear power industry: An overview of the R3 impact assessment procedure

The R3 Impact Assessment Procedure was developed by Magnox Electric Ltd and its predecessors with the prime intent of providing a compendium of methodologies for assessing the effect of dropping nuclear fuel flasks on steel and concrete surfaces. However, since then the intent of the procedure has broadened and as eventually released encompasses three volumes, namely:Volume 1 – missile production primarily arising from pressure boundary failure or rotating plant failure, jet and blast loading, global pressurisation.Volume 2 – whipping pipe motion following pipe failure.Volume 3 – target response – the response of concrete and steel structures to impact and the effect of pipe impact on pipes and beams.The procedure is firmly based on correlations derived from appropriate tests and does not, in general, rely on Finite Element analysis. The advantage of this approach is that it provides bounding results which frequently indicate that further, more advanced, analysis is not required. The procedure may be used as a filter to identify potential problems quickly. Where necessary, analysis methods can be refined in these areas to provide support to safety arguments. The paper presents an overview of the procedure with examples of applications.