To provide inspectors with an effective tool for non-intrusive verification of spent nuclear fuel, a global leader in nuclear safeguards technology asked Resolve Optics to design a wavelength corrected UV Zoom lens to enable its Digital Cerenkov Viewing Device to view a nuclear fuel assembly situated 13 metres away from the lens and through 10 metres of water. Spent nuclear fuel emits a faint UV (Cerenkov) light when gamma rays from fuel assemblies interact with electrons in the cooling pond water. To meet the challenges of this demanding application – Resolve Optics designed the UV zoom lens to optimally operate from 10 to 55ºC.
Imaging objects from 3m to infinity
By incorporating a telescopic focus in the design, the novel lens can image objects from 3m to infinity. Miniature motors on the lens allow accurate remote setting of both zoom and focus functions. A filter slide was also incorporated in the design enabling the lens to be switched between UV (270 to 350 nm) and visible (400 to 700 nm) without the need for refocusing. The lens achieves high image resolution with low distortion throughout the zoom range without refocusing. A lockable C mount ensures the lens cannot come loose during operation. The Digital Cerenkov Viewing Device equipped with UV Zoom lens provides a highly effective system that captures the Cerenkov image of spent nuclear fuel for analysis and comparison.