On June 30, 2020, the NRC issued a Notice of Violation to Centro Comprensivo de Cancer de la UPR (Licensee), for a Severity Level III problem associated with two related violations. The first violation involved licensee's failure to maintain or adequately control a high dose rate remote afterloader (HDR) unit, the HDR console, the console keys, and the HDR treatment room as required by Title 10 of the Code of Federal Regulations (10 CFR) 35.610(a)(1) and the second violation involved the resultant failure by the licensee to secure from unauthorized removal or access licensed material as required by 10 CFR 20.1802. Specifically, on November 21, 2019, the licensee's medical physicist left the treatment room area and inadvertently left the HDR console keys in the console and the key securing the HDR unit, as well as the key and keycard used to access the outer door of the HDR unit room, unsecured on the desk and during this period the licensed material was not secured from unauthorized removal or access.