The European Union’s Nuclear Safety Directive 2014/87/EURATOM (NSD) requires the member states to undertake topical peer reviews (TPR) every 6 years with the first starting in 2017. The member states, acting through the European Nuclear Safety Regulators Group (ENSREG), have decided that the topic for the first topical peer review is ageing management.
The Swedish Radiation Safety Authority (SSM) by the provision of the act of nuclear activities (1984:3) can decide by injunction that licensees take the necessary measures required in individual cases for compliance with the act. Based on this legislation SSM in February 2017 decided that licensees operating nuclear reactors should report relevant information according to the technical specification (RHWG Report to WENRA – TPR Technical Specification, 21 December 2016). This report, issued by SSM, is based on the licensee’s assessments and the results from SSM’s review.
Reports from all licensees were provided to SSM in June 2017. All information was processed and compiled in this report by SSM during July to October 2017, whereafter the licensees had an opportunity check for any factual inconsistences. Finally, the Swedish national report was completed and distributed to ENSREG in December 2017.
Based on SSM’s performance based regulatory philosophy Swedish licensees have pursued slightly different paths to develop their respective overall Ageing Management Programmes, all with the goal to ensure the availability of required safety functions throughout the service life of the plant. SSM introduced the requirement to develop overall programmes for ageing management in late 2004.
In developing the overall Ageing Management Programmes, Swedish licensees have largely compiled information from already existing programmes, such as maintenance, component qualification, in service inspection and chemistry programmes. Using these programmes a lot of experience gained from the operation of the licensees reactors as well as external ageing related experience has been used. The overall Ageing Management Programme have therefore naturally become an interdisciplinary programme linking ageing perspective in a range of programmes. The key elements used by the Swedish licensees to assess ageing are based on the nine attributes in NS-G-2.12, which are similar to the ten elements described in NUREG-1801. It is SSMs opinion that since Swedish licensees started to develop their overall Ageing Management Programme after approximately 20 to 30 years of operation, it is natural that ageing assessment has been based on these programmes more than for instance on manufacturing documents. Additionally, Swedish licensee´s in order to check consistency, have used IAEA SRS 82 and NUREG-1801 in the ageing assessment. To have an international assessment of the overall Ageing Management Programmes, all three licensees have also conducted IAEA SALTO or pre-SALTO reviews.