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Castable Shielding

On-site casting is sometimes the only way to achieve the  desired shielding. Our castable shielding products can be used to fill walls, surround spent fuel and withstand high temperatures.


Small Mix Kit



SWX-237 High Temp Boron-Silicone
SWX-237-0 High Temp Poly Substitute (Boron Free)

Boron-Silicone is a fire-resistant, heat-resistant, field-castable elastomer with a high hydrogen content. It is self-extinguishing and will withstand temperatures up to 400° F (205° C) for extended periods while retaining 90% of its hydrogen. Boron-Silicone contains 1% boron for thermal neutron capture and the suppression of capture-gammas.

Other boron concentrations can be supplied upon request.



SWX-237-0 Poly-Substitute is a boron free version of the standard silicone elastomer mix, boasting the same physical properties, including the high hydrogen content and high temperature specification.  It is frequently used when fire and temperature restrictions prevent the use of HDPE.

Although this is a solid material, its resiliency will minimize secondary missile formation due to impacts.  Its density is 1.59 g/cc (99 lbs./cu ft).

Boron-Silicone is available in a variety of shapes and sizes. Shieldwerx has provided large pre-cast rings for use as a shield for coolant recalculating lines.  The material is also used in the manufacture of large fuel transportation containers.

Quantities Required to Cast One Cubic Foot:


Type      Dry Mix

237        99 lbs

259        56 lbs

277        96 lbs

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