Radiological protection report 2009

On January 1st 2009, HSK became ENSI, the Swiss Federal Nuclear Safety Inspectorate and at the same time the body became independent of the Swiss Federal Office of Energy. However, the task of the new regulatory body remains unchanged. ENSI continues to monitor ionising radiation and radioactivity in Swiss nuclear facilities and their immediate vicinity. It prepares forecasts on the potential course of any nuclear incident, including the spread of radioactivity into the environment. It also judges whether measures adopted by operators of nuclear facilities are appropriate. This is the sixth annual summary report on the radiological protection issues regulated by ENSI. The year under review was marked by an incident at the Beznau nuclear power plant that was thought to be impossible in Switzerland. Two individuals exposed to radiation as part of their work received radiation doses in excess of the annual limit of 20 millisievert (mSv), something that has not happened in the areas regulated by ENSI since the introduction of the Radiological Protection Ordinance in 1994. As a result of this incident, ENSI instituted proceedings under administrative criminal law. Despite this, ENSI concluded that radiological protection is being carried out consistently in Swiss nuclear facilities. Measures to optimise radiological protection have reduced exposure rates significantly. This has been helped by the fact that in recent years, operators have consistently introduced hydrochemical measures in accordance with the latest developments in science and technology. The challenge now facing the operators of nuclear facilities in Switzerland is to maintain the high levels of radiological protection and reduce the higher exposure levels experienced by certain specialists. In addition, operators must give particular attention to work performed in high and variable radiation fields. Section A of this annual report deals with exposure rates for personnel and individual jobs. In recent years, facilities have reduced collective doses and average individual doses by a factor of two. The average individual exposure rate for personnel in nuclear facilities is now 0,6 mSv. This is significantly lower than both the maximum annual limit for persons exposed to radiation during their work and the average annual radon exposure rate of 1,6 mSv for the population in Switzerland as a whole. At the Beznau nuclear power plant, the highest individual dose was 37,8 mSv, which was significantly higher than the annual limit. At the nuclear power plants of Goesgen, Leibstadt and Muehleberg, the maximum individual dose was in each case less than 10 mSv. Exposure to higher doses was restricted to individual specialists working on components with high local dose rates and for whom it would not have been easy to replace with other personnel. Section B of the report contains information on the monitoring of environmental radioactivity in the vicinity of nuclear facilities. For this purpose, ENSI has established a network that automatically monitors dose rates in the vicinity of nuclear power plants and this network has been operating as a matter of routine for many years. The monitoring results are publicly available. Emissions from Swiss nuclear facilities are comparable with previous years and the maximum annual exposure rate for infants in the immediate vicinity of a nuclear facility was below 10 microsievert. ENSI monitors scientific and technological developments relating to the atmospheric dispersion of radioactive particles and introduces changes as appropriate. The CN-MET Project (Centrales Nucleaires et Meteorologie) was successfully completed in 2009 and so MeteoSwiss now provides high-quality meteorological information designed to improve the protection of the public in the event of an incident resulting in the release of radiation