Lead Alternatives: Innovating the Radiation Shielding Industry

The development of non-lead shielding materials is an area that material sciences is advancing in the field of radiation shielding. Lead remains the most commonly used material for radiation shielding because of the ease to be able to work with it, the price, and most prominently its ability to reduce gamma radiation. However, one drawback of lead is that it is a toxic substance if ingested into the body. Because of this, innovations are being made to produce thinner, more flexible, and effective non-lead shielding. Specifically, polymers are being utilized for their material properties and infused with tungsten and other metals to produce a new generation of shielding products.

Composition of Polymer Based Shielding Materials

Non-lead alternatives come in a variety of forms. The main sheet form is metal impregnated polymers which are a polymer that contains a shielding material. This capitalizes on the shielding properties of the metal, and the flexibility of the polymer.

The composition of these materials can vary depending on the product but generally, a polymer base is used for the product. Materials, such as metals and non-lead, high atomic numbered elements are added for shielding including Tungsten, Bismuth, and Iron. The percentage of these materials can vary anywhere from 0-95% of the material depending on the product. In addition, to improve the material properties, other materials like glass and carbon fibers are also in the material.

Metal Impregnated Polymers – T-Flex

The T-Flex® Shielding Range – a line of new radiation shielding materials have been commonly used in the Nuclear industry as an alternative to lead wool blankets or solid lead parts. Usually made with a shielding material of iron, bismuth or tungsten, these materials come in sheet or roll form, or can be molded and extruded. In addition, magnets or gromets can be placed in the materials to allow for hanging from racks or attaching to metal surfaces. Protective layers can also be added to increase the durability of a sheet of material. Mainly, this material is used in the nuclear energy and non-destructive testing (NDT) industries.

Table 1: T-Flex Attenuation of Co-60 Gamma Radiation (1250 keV)

Material Thickness T-Flex Tungsten T-Flex Bismuth T-Flex Iron
0.25” 17% 12% 6%
0.5” 32% 24% 12%
1” 54% 42% 23%
2” 80% 67% 41%
4” 96% 90% 66%

Nanotek ShieldingNanotek Shielding

Metal impregnated polymers are mostly found within the nuclear industry, however, due to high cost and thicker materials, those materials are often not as well suited for other industries that need shielding such as in diagnostic imaging and NDT.

There are two main types of NanotekTM Shielding to address a wide variety of uses of shielding materials. NanotekTM XYZ was developed to provide a cost-effective alternative to lead radiation shielding. The result is a polymer based shielding material that can be made into thin materials to replace sheet lead and installed on walls with its adhesive backing, or the material can be used to provide thicker shielding in the form of interlocking bricks. XYZ can be molded into custom shielding pieces and used as curtains, shielded vest, barriers, nuclear medicine vials and other shielding or storage products.

Table 2: NanotekTM XYZ Attenuation of X-Ray Radiation

Material Thickness (XYZ) 150 kVp 120 kVp 80 kVp
1.0 mm 44% 59% 78%
2.0 mm 68% 82% 94%
3.0 mm 79% 90% 98%
4.0 mm 86% 94% 99%
5.0 mm 81% 96%
6.0 mm 92% 97%
7.0 mm 94% 98%

NanotekTM RSM is a material that is designed to provide a lightweight alternative to lead. While the cost is greater than lead or Nanotek XYZ, this product can provide better X-Ray protection in thinner layers and weigh less than conventional lead or other lead alternative shielding.

Table 3: NanotekTM RSM Attenuation of Iodine-131 (364 keV)

Material Thickness NanotekTM RSM
2.70 mm 32%
5.45 mm 52%
8.17 mm 71%
10.90 mm 79%
16.30 mm 88%
21.73 mm 93%

Using tungsten and other heavy metal composites is an innovative way to provide effective shielding and is a viable alternative to lead. Due to the flexibility and non-toxicity, the possible uses of these materials are endless.

If you would like to find out more information about what shielding solutions MarShield can come up with, you can find more information from the MarShield website or you can contact MarShield directly, and we will help you find the right radiation shielding solution for you.

MarShield Custom Radiation Shielding Products provides radiation shielding solutions for the Medical and Nuclear Industries and is a division of Mars Metal Company. Contact us today to discuss your unique radiation shielding needs!

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About the Author

Paul Rochus

Paul Rochus is the Business Development Executive and a Shielding Technician at MarShield Radiation Shielding since January 2019. Before his time at MarShield, Paul completed his Bachelors of Engineering from McMaster University in Engineering Physics with a focus on Nuclear Engineering and Energy Systems. At McMaster, Paul developed knowledge in radiation safety and interaction of radiation with matter, as well as nuclear reactor design and analysis.