NRC Approves NAC International’s OPTIMUS®-L to Transport High Activity Radioactive Sources

NAC International Inc. (NAC) has announced that it has received regulatory approval from the U.S. Nuclear Regulatory Commission (NRC) for its patented OPTIMUS®-L packaging system to transport High Activity Radioactive Sources (HARS). This certification enhances the capabilities of our already versatile OPTIMUS® systems, which are fabricated and licensed to transport a range of radioactive materials from HALEU (high assay low-enriched uranium) fuel to used fuel from nuclear power plants. 

The OPTIMUS-L system’s expanded capacity to transport high-activity sources in a wide range of environments opens the door for NAC to provide more cost-effective transportation and disposal options for our customers. The NRC approval effective April 30, 2025 enables NAC to transport shielded sealed source devices used in a wide variety of applications using the OPTIMUS-L system (packaging and contents).

This certification represents an advancement in NAC’s mission to provide safe, efficient, and scalable solutions for the transportation of radioactive materials. The OPTIMUS-L system is now licensed to carry a broader range of high-activity contents, including sealed sources such as Cesium-137 and Cobalt-60, widely used in medical, industrial, and research applications.

A New Standard in High Activity Source Transport

The OPTIMUS-L system, originally developed to support the shielded transport of lower dose radioactive waste, now supports higher activity materials through a Phase II development program. In response to industry demand for a compact, lightweight, and modular Type B(U)F package, NAC enhanced the system’s capabilities with a novel licensing approach that takes into account the shielding provided by sealed source devices themselves.

This innovation enables OPTIMUS-L to safely transport high activity sources without requiring additional external shielding. This is ideal for use in constrained environments such as hospital loading docks, laboratories, and urban facilities without extensive overhead lifting capability.

The enhanced OPTIMUS-L system accommodates up to 2,800 curies of Cesium-137 and 5 curies of Cobalt-60, with a thermal load of approximately 13.5 watts, well within the system’s 50-watt limit. These capabilities are validated through rigorous structural, thermal, and shielding analyses, including dynamic simulations and MCNP6.2 modeling, ensuring full compliance with NRC safety requirements under both normal transportation conditions and hypothetical accident conditions.

Operational Flexibility and Efficiency

NAC’s OPTIMUS Type B systems are designed for maximum adaptability to transport a wide range of radioactive materials. The OPTIMUS®-H license accommodates high activity contents such as spent nuclear fuel and remote-handled transuranic waste. OPTIMUS-L can be used for lower activity contents such as contact-handled transuranic waste, High-Assay Low-Enriched Uranium (HALEU), and mixed low-level radioactive waste. OPTIMUS-H and OPTIMUS-L offer numerous operational advantages over traditional large format Type B packages:

• Compact footprint (49 inches in diameter, 9,200 pounds) compared to larger systems typically used to transport high-activity sources
• Modular design allows for scalable deployment and simplified logistics
• Common Cask Containment Vessel across OPTIMUS-H and -L systems standardize operations and reduce training requirements
• Forklift compatible pallets enable quick and safe loading and unloading. This eliminates the need for overhead rigging infrastructure or mobile cranes
• Certified for use in both the U.S. and Canada, expanding its applicability across North America
• Designed to meet IAEA-SSR-6 criteria, for ease of Competent Authority approval in your country

These features make the OPTIMUS-L particularly well-suited for the retrieval, replacement, and disposal of disused sealed sources, especially in facilities that no longer wish to maintain a radioactive materials license or are transitioning to newer technologies.

Supporting a Safer, More Adaptable Nuclear Industry

The OPTIMUS product line reflects NAC’s commitment to innovation and adaptability in the nuclear sector. By offering a flexible, high-performance solution for transporting a wide range of radioactive materials including intermediate level waste, transuranic waste, and irradiated components, NAC is modernizing the infrastructure that supports nuclear safety, research, and energy development.

NAC continues to expand the OPTIMUS-L licensing basis to include additional sealed source configurations and shielded irradiator devices, enhancing its versatility and reinforcing NAC’s position as the premier provider for nuclear materials lifecycle management solutions.

For more information about NAC’s OPTIMUS transportation systems visit: https://www.nacintl.com/solutions/transportation/transportation-systems/optimus