A transponder card for a nuclear reactor control rod drive control system is provided. The pair of entangled photons is divided into two beams, one of which illuminates a semi-reflective object and the second of which is reflected from a variable optical time-delay element. A tubular extension is thermaly connected to and extends from the tubular member. The selected content items are grouped into explicit conceptual clusters and user-implied conceptual clusters based on metadata in common to the selected content items. The spray ring does not extend past a surface of the first window facing the aperture and each of the cleaning ports is oriented such that a fluid provided under pressure to the cleaning ports is ejected toward the second window.