Electropotential Verification for Nuclear Facility Design Information Verification

Verifying that a nuclear facility’s infrastructure matches the declared design is vital to the continued success of international safeguards regimes. Electropotential verification (EPV) is a newly proposed verification method that could provide real-time online monitoring of a facility’s infrastructure design. EPV works by passing a low-voltage current through a conductive infrastructure such as pipes in a uranium enrichment plant and taking voltage readings from various probing locations throughout the infrastructure network to establish baseline values. Deviations from the baseline readings would point toward changes made to the system configuration, which could indicate possible undeclared activities. EPV has two large advantages over DIV methods that rely on line-of-sight approaches such as visual inspection or 3D laser scanning. First, because the low electrical current will interrogate and detect changes throughout the entire infrastructure network, portions of the facility deemed sensitive or proprietary do not have to be visually inspected. Second, significant alterations to the system can be detected and flagged instantaneously instead of during periodic inspections. To show the viability of this technique, a laboratory-scale tabletop network of stainless-steel pipes was constructed, which is analogous to the complex piping infrastructure present in a facility. Measurements of this mockup have shown successful detection of system alterations, including the addition, removal, or change in the location of grounded elements. Additionally, the software Hi-FEM, which uses hierarchal finite element modeling to simulate electrostatics, was used to model the laboratory measurements. The models showed good agreement in relative potential differences throughout the network. This model validation is important to show that the simulation tool is viable to use in further study of EPV. Future efforts will work to show concept viability on a larger scale and create conceptual instrumentation designs for concept implementation.