A one day workshop organised jointly by FESI and the Office for Nuclear Regulation (ONR) on Beyond Code Safety Requirements for Nuclear Pressure Systems was held at BAWA, Filton, near Bristol, on 10th April 2019.
ONR considered that it would be useful and timely to hold the event based on its experience in recent years of assessing safety case submissions from licensees and designers associated with new nuclear build. This experience indicated that ONR’s ‘beyond code’ expectations regarding highest reliability structures and components (those for which gross failure is discounted) may not always be clearly understood. The objectives of the workshop were to clarify these expectations and to identify where advice and/or interpretation for structural integrity measures beyond codes and standards could be improved. The workshop was attended by approximately forty participants.
The morning sessions primarily consisted of the ONR and licensees’ representatives giving short presentations on three disciplines that contributed to structural integrity: materials testing, welding and manufacturing control; non-destructive examination (NDE) and inspection qualification; and stress and defect tolerance evaluation.
In the afternoon, discussion groups were held in parallel for each of the technical areas, the aim of which was to consider the various aspects relating to how beyond code safety requirements could be met identifying: good practices; areas for Improvement; shortfalls (if any); and developments and emergent issues. The three ONR representatives who led the parallel sessions then presented back to all the participants highlighting the main points that emerged from the discussions.
Post event, the outcome of the discussions, largely based on the information compiled on the outline sheets, is being collated. This will inform ONR decisions on which aspects there would be benefit in addressing in terms of its approach and its guidance to inspectors (these may be short term or longer term matters), and which are matters that the industry could consider taking forwards. ONR will then write a summary of the feedback from the event and what it thought was actionable. A further short piece on the event will be published in the FESI Bulletin, including the summary by ONR.
The format of the workshop, being a combination of presentations and discussion groups, had been somewhat different to that of previous FESI events. Based on the generally positive feedback received from the participants, it would certainly be worth using this type of format again in the future for when FESI members may have a particular structural integrity related topic or issue they would like to be aired on a wider basis than within their organisation.
John Sharples
The photograph above shows an aerial photograph of Sizewell B Nuclear Power Station, Électricité de France (EDF’s) nuclear power station in Suffolk, England. This plant supplies 3% of the UK’s electricity.