Radiation Shielding Design Process
Alexandra Adrych-Brunning is a Senior Radiation Physics Consultant at TÜV SÜD Nuclear Technologies and is an ambassador for the Women in Nuclear network.
The risk from ionising radiation can be reduced by minimising exposure time and increasing the distance from the radiation source. However, when these measures are insufficient or impractical, shielding is necessary. This article outlines the Shielding Design Process which was developed in the late 1990s by BNFL( now Sellafield Ltd) to optimise the design and implementation of radiation shielding. be assessed, as this influences the shielding requirements. In addition to primary sources, secondary radiation must also be considered, such as capture gammas that arise when neutrons interact with shielding materials.
This information, known as the source term, is compiled into a basis of design report, which serves as the foundation for shielding assessments. This report includes key parameters such as dose rate criteria, dose limits, shielding material properties and conversion factors.
Designing the Shielding Shielding design is dictated by how people interact with the radiation source, with the objectives of managing exposure dose rates
Understanding the Radiation Source The first step in shielding design is identifying and characterising the radiation source, which could, for example, be nuclear waste, nuclear fuel or medical radionuclides. It is necessary to establish the type of radiation being emitted, whether alpha, beta, gamma, neutron or a combination of these. The intensity or activity level of the radiation must and the potential doses received. Dose rate limits are determined by occupancy( the amount of time a person spends in the radiation field) and the dose accrued. Highradiation areas require low occupancy, while areas with lower dose rates can tolerate higher occupancy. Radiation levels in different locations are recorded in a designation of areas report, which aligns with
24 Radiation Protection Today www. srp-rpt. uk