Gamma radiation shielding is an important component of radiation safety programs aiming to reduce personnel exposure to ionizing radiation. Attenuation data for commonly used shielding materials is available in many resources, such as the National Institute of Standards (NIST) XCOM database of attenuation coefficients and Health Physics and Radiological Health.  Ultimately, selecting the most appropriate gamma radiation shielding material for a given source of ionizing radiation will require knowledge of the source of radiation, application of attenuation data from available resources, and understanding of the basic principles of gamma ray interactions with matter.  Other factors such as cost and chemical compatibility must be considered. The basic information required for assessing the relative merits of a wide range of shielding materials is covered in our Gamma Attenuation White Paper.

NPO contracted TEAM Industrial Services to conduct a benchmarking study to evaluate the attenuation of Co-60 gamma dose reduction achieved by various commercially available shielding materials. Multiple replicates (n = 3 – 9) of products made from lead wool, tungsten, bismuth, and iron were compared to each other and to a solid lead plate benchmark. The attenuation directly correlated with a single factor, cross-sectional density of the shielding material (or mass of shielding material in the path of the gamma radiation, i.e., mass-in-the-path). Neither the physical format of the shield (solid lead, lead blanket, or flexible shielding) nor the identity of the supplier had a significant impact on the results obtained in this study.

Team Industrial – Gamma Attenuation Benchmarking Study, August 2021 – redacted