Abstract

In 2020, the gamma radiation level at the site boundary of the Borssele nuclear power plant was below the maximum permitted level of 10 microsievert per year. The maximum effective dose was 1.2 microsievert. This is the result of measurements carried out by RIVM on location. RIVM is tasked by the Authority for Nuclear Safety and Radiation Protection (ANVS) to report annually on whether the Borssele nuclear power plant meets the criterion stipulated in the licence.

The nuclear power plant must ensure that the maximum exposure of persons outside the site boundary does not exceed 10 microsievert annually. This is stipulated in the revised 2018 Nuclear Energy Act licence. In order to determine the maximum effective dose, gamma radiation is measured at the site boundary. The measurements are carried out within the framework of the MONET monitoring network, which falls under the administrative management of RIVM. The measurements are then corrected by subtracting the natural background value.

The resulting measurement data are then corrected with the so-called Actual Exposure Correction Factor (ABC factor). An ABC factor takes into account the specific use of the area where exposure to the gamma dose may occur. Around the boundary of the Borssele nuclear power plant, the zoning plan only specifies industrial use, which is associated with an ABC factor of 0.2. After applying this factor, the maximum effective dose resulting from external gamma radiation is 1.2 microsievert per year.

In 2020, measurements of the gamma radiation level were carried out continuously at eight locations at the site boundary. This report provides the daily averages of the radiation dose recorded by the MONET monitors around the Borssele nuclear power plant and explains how the background level at each measuring location was determined.