Radiological Impact Assessment

NRG supports organisations with respect to Radiological Impact Assessments (RIAs). These assessments, calculate the consequences of activities and work in which man and the environment are exposed to radiation. Such an analysis is required when applying for a licence in the context of the Nuclear Energy Act as well as for an environmental impact assessment (EIA).

NRG has several dispersion models with which Radiological Impact Assessments of varying complexity can be approached. NRG’s specialists are familiar with state-of-the-art modelling software and can use it to supply tailor-made work. Radiological Impact Assessments can be prepared for the following scenarios:

• Radiation shielding
• Dispersion of radionuclides in air
• Dispersion of radionuclides in water

Radiation shielding
NRG has both simple and complex software to calculate transmission factors and shielding materials for different types of radiation. This enables us to advise on the optimal dimensioning of shielding, area layout and selecting the appropriate shielding materials. We can also advise about shielding for radioactive sources and the personal protection of employees.

Dispersion of Radionuclides in the Air
In larger nuclear installations, such as nuclear reactors, radionuclide laboratories and cyclotrons, dispersion of radionuclides into the surroundings occurs via the air. In unforeseen circumstances, such as in a fire, high levels of radioactive substances might be emitted. For a Nuclear Energy Act licence, an analysis of the consequences of these emissions for man and environment is mandatory.

The software which NRG uses to model the emissions of radionuclides in air is based on a Gaussian plume model and complies with the Guidelines of the New National Model prescribed by the Dutch government. For complex situations, taking into account the influences from the built environment, NRG possesses Computational Fluid Dynamics software.

Dispersion of Radionuclides in Water
In nuclear installations, such as nuclear reactors, dispersion of radionuclides usually occurs via water. In unforeseen circumstances, such as in flooding, a greater discharge of radioactivity might occur. For a Nuclear Energy Act licence, an analysis of the consequences of these discharges for man and environment is mandatory.

NRG has an internationally validated 3D hydrological model which can model the dispersion of radionuclides in water. This model is unique because, besides providing an accurate description of the water flows, it also enables the dispersion of the radionuclides in biota (animals and plants) and sediments to be mapped out accurately.

NRG advises and supports clients at both national and international level with the calculation of the dispersion of radionuclides in water.