Simulation and experimental validation of spent nuclear fuel cask shields

Area of Science:

• Nuclear Engineering
• Materials Science
• Radiation Protection

Background:

• Spent nuclear fuel requires robust shielding for safe transport and storage.
• Dual-Purpose Casks (DPC) are critical for managing spent fuel.
• Accurate modeling of radiation sources and shield performance is essential.

Purpose of the Study:

• To design and validate an effective radiation shield for metallic Dual-Purpose Casks (DPC).
• To ensure compliance with international radiation safety standards (SSR-6).
• To combine computational simulations with experimental validation for shield optimization.

Main Methods:

• Utilized ORIGEN 2.1 for calculating neutron and gamma fluxes from spent fuel.
• Employed Top-Mc software for simulating radiation shield performance in DPCs.
• Validated simulation results through laboratory experiments and MCNP code.

Main Results:

• Identified Cm-244 as the dominant neutron source after 5 years of cooling.
• Developed a 10 cm composite shield with 20% boron carbide, reducing surface dose to 1.98 mSv/h.
• Experimentally verified 99.69% thermal neutron absorption for a 0.99 cm thick shield.

Conclusions:

• The combined computational-experimental approach successfully designed a compliant radiation shield for spent fuel DPCs.
• The developed composite shield offers efficient radiation attenuation for transport and storage.
• Experimental validation confirmed the accuracy of the simulation methods used.