The Feasibility of Passive Neutron Measurement for Dry Storage Safeguards Approach

This work investigates the feasibility of using passive neutron measurement in identifying the removal or diversion of spent nuclear fuels (SNFs) in dry cask storage. In particular, we adopted a tomographic approach to measure emitted neutrons along the cask's periphery through a laboratory-scale demonstration. An Arktis S670e helium-4 (He-4) detector array was utilized to measure neutrons. A 1/10th model cask was also built to mock the TN-32 dry cask. The test bench was conducted with three 252 Cf sources to exemplify different assembly loading configurations. The measured neutron intensity patterns were then used to create images that represent the different source configurations. Also, Monte Carlo N-Particle Transport (MCNP) simulation was carried out to intercompare the experimental results with computational ones. Here, we describe the details behind the proposed safeguards technique through laboratory-scale demonstrations and examine its potentials and limitations.