Novel Steel Composite for Nuclear Shielding

Background

In nuclear reactor environments, particularly within fission and fusion reactor cores, effective radiation shielding is critical to ensure both the safety and longevity of the structural components. These reactor cores are constantly exposed to intense neutron and gamma/x-ray radiation, which can degrade materials and components over time and pose significant risks to both the reactor’s integrity and the surrounding environment. As reactor technologies advance and power outputs increase, the demand for more efficient and robust shielding materials that can simultaneously manage multiple types of radiation while maintaining structural strength becomes increasingly important. The ability to protect against diverse radiation forms without compromising the reactor’s mechanical stability is essential for the sustainable and safe operation of next-generation nuclear facilities. Current shielding solutions typically employ separate materials and layered approaches to address different types of radiation, which introduces several inefficiencies and limitations. For instance, high electron density materials like lead or tungsten are used for gamma/x-ray shielding, while neutron protection often requires a combination of moderating substances such as water or polyethylene and neutron-absorbing elements like boron or hafnium. This multi-layered strategy not only consumes valuable space within the reactor design but also fails to optimize the overall shielding effectiveness. These shortcomings highlight the need for efficient shielding solutions that can streamline reactor designs and enhance radiation protection.

Technology

The technology is a novel structural steel composite for mixed neutron and electromagnetic radiation shielding application. The composite has an iron-based steel alloy matrix and a metal-hydride (MH) secondary phase(s) with one or more high neutron-absorbing and moderating MHs. By utilizing an innovative fabrication process at lower temperature and pressure, the steel preserves the hydride phase, allowing for up to 55% metal hydride content without decomposition, enabling the production of thick plate geometries while maintaining the integrity of the metal hydrides. What sets this technology apart is its ability to combine neutron moderation, neutron absorption, and electromagnetic shielding into a single, cohesive and structural material. Traditional shielding solutions typically require separate layers or materials to address each type of radiation, leading to spatial inefficiencies and compromised performance. In contrast, this composite steel streamlines the design by integrating all necessary shielding functions, resulting in enhanced effectiveness in reducing fast neutron flux and superior structural integrity in high-radiation environments. This steel composite outperforms conventional materials like water, boronated steel, and boron carbide, offering a more efficient use of space, improved shielding performance, and a simplified design. This makes it a significant advancement for nuclear applications demanding comprehensive radiation protection without sacrificing structural functionality.

Advantages

Integrates neutron moderation, absorption, and electromagnetic shielding into a single material, simplifying reactor design. Superior shielding effectiveness against fast neutrons compared to traditional materials. Maintains structural integrity and mechanical strength in high-radiation environments. Allows up to 55% metal hydride content without decomposition. Efficient use of space by eliminating the need for separate shielding layers. Optional inclusion of borides for enhanced neutron absorption or electromagnetic protection.