Implementation of the obligations of the convention on nuclear safety. Fourth Swiss report in accordance with Article 5

Switzerland has signed the Convention on Nuclear Safety. Most of the requirements of the articles of the Convention were already standard practice in Switzerland. In the last years, all Swiss nuclear power plants (NPPs) as well as the Swiss Federal Nuclear Safety Inspectorate (HSK) built up documented quality management systems. The independence of HSK from licensing authorities is fulfilled on a technical level. In 2005, a new Nuclear Energy Act came into force requiring formal independence of the supervisory authorities from the licensing authorities. A separate act to legally settle the Inspectorate's fully independent status was adopted by Parliament. HSK participates in international projects and is represented in numerous nuclear safety working groups in order to ensure the exchange of scientific, technical and regulatory know-how. The regulatory processes applied to the licensing and safety surveillance of nuclear installations and their operation are up to date with the current state of science and technology. Deterministic and probabilistic safety evaluations guide and prioritise inspections and provide the basis for a graded approach to safety review and assessment. The surveillance of the NPPs' operating, control and safety systems, their component performance and integrity, their organisational and human aspects as well as the management, conditioning and interim storage of radioactive waste are permanent features of the supervisory authority's activities. Within the frame of a new integrated oversight process there is an annual systematic assessment of nuclear safety for each NPP based on the analysis of events, inspection results and operator licensing reviews. The assurance of low radiation doses to both NPP workers and the general public is an additional goal that is directly associated with the safe operation of NPPs. In case of an accident in a nuclear installation, contingency plans are in place and are continually updated. Emergency drills are conducted at regular intervals. The international alerting system is also in a mature stage. The first generation of NPPs in Switzerland has been the subject of progressive back-fitting. The second generation of NPPs incorporated various safety and operating improvements in their initial design. All Swiss NPPs have undergone the safety review process required under the Convention and have incorporated the improvements identified in the respective safety review reports. The Swiss policy of continuous improvements to NPPs ensures a high level of safety. The legislation and regulatory framework for nuclear installations is well established. It provides the formal basis for the supervision and the continuous improvement of nuclear installations. The supervisory authority conducts inspections and technical discussions with the utilities to ensure that operators assume full responsibility for the safety of their installations. All NPPs have implemented programmes to improve their safety culture. Plant-specific full scope replica simulators are operating at all Swiss NPPs. The Inspectorate's organisation includes staff members dealing with human aspects, NPP organisation, and safety culture. Considerable attention is paid to human factor aspects of operator support systems, including procedures, guidelines and checklists. The review and assessment procedure includes an evaluation of the safety analysis report, safety-relevant systems, design-basis accident analyses, probabilistic safety analysis and reports on ageing surveillance programmes. An Ageing Surveillance Programme is in place for all NPPs in order to maintain safety margins and safety functions of structures, systems and components throughout the plant lifetime. Concerning the radiation protection, the supervisory and control methods currently applied by the inspectorate are in compliance with the Convention's requirement to keep radioactive doses to the public and the environment as low as reasonably achievable and also to keep the generation of radioactive waste associated with the use of nuclear power at the lowest possible level. There is an automatic dose rate monitoring and emergency response data system in and around all NPPs in Switzerland. All Swiss NPPs have a special independent, bunkered system for shutdown and residual heat removal. The various levels of defence that exist ensure that safety limits and individual dose limits for the public are met during normal operation of the NPP and for all design-basis accidents