The influence of experience and knowledge on reactor safety in Germany

Abstract

After five decades of nuclear power generation in Germany, the government decided to phase out nuclear power plants until 2022 as a consequence of the Fukushima disaster in 2011. Electricity generation is accompanied by human and technical errors, which questions if the nuclear phase-out has an influence on reactor safety. Past errors, available as so-called reportable events of nuclear power plants, can be approximated with experience measured in cumulated electricity generation by applying the Duffey-Saull method with a high coefficient of determination (R 2 = 0.84). Errors are declining with growing experience, which means the reportable events per TWh are declining over time. Today, approximately 0.9 reportable events per generated TWh occur and, given unchanging operational conditions, it is expected to remain at this magnitude in the near future. Moreover, knowledge induced by public Research and Development expenditures may supplement experience in reducing reportable events. Thus, the cumulative fission knowledge stock of Germany was added to the Duffey-Saull method for the first time. By adjusting the knowledge depreciation rate within this extended method, the prediction of reportable events is more accurate. Best results were obtained with 10.8% depreciation rate, which is also in line with the literature.