Over the years 2015 and 2016, the radiation level caused by gamma radiation at the site boundary of the COVRA N.V., the Central Organisation for Radioactive Waste, was below the maximum permitted level. This is the conclusion of this report based on field measurements carried out by RIVM.
Dutch legislation on the use of nuclear energy requires that the maximum dose rate at the site boundary of the COVRA N.V. does not exceed 40 microsievert annually. Control measurements of the gamma radiation level were therefore carried out with gamma radiation monitors placed at twelve locations at the site boundary.
This is done within the framework of the MONET monitoring network, which falls under the administrative management of the RIVM. The measurements are processed by subtracting the natural background
The result is then translated into the effective radiation dose for an individual by applying the so-called 'Actual Exposure Correction factor' (ABC-factor). ABC-factors are closely linked with the specific use of the site where the effective radiation dose is calculated.
RIVM is tasked by the Authority of Nuclear Safety and Radiation Protection (ANVS, formerly known as KFD) to annually report on whether COVRA N.V. meets the criterion set out in its license. Both the daily averages of the effective gamma dose around COVRA N.V. are shown and an explanation of how the background level for the MONET monitors is determined is provided in the report.
Over the period 2015 to 2016 the highest gamma yearly dose, to which the ABC-factor is applied, is found to be 2,9 and 3,0 microsievert respectively. This is lower than the value of 40 microsievert per year which is stipulated in the permit.