Transmission of information using elastic waves on existing metallic pipes provides an alternative communication option for a nuclear facility. The advantages of this approach consist of transmitting information through barriers, such as the containment building wall, and providing an option for nuclear facility physical cybersecurity. Ultrasonic carrier frequency elastic shear waves confined to a metallic pipe create a communication channel which is difficult to eavesdrop on without direct physical contact. Compared electric or fiber optic cables, the communication channel consisting of a thick nuclear-grade stainless steel pipe is resilient to physical damage, such as channel severing. In this paper, we discuss acoustic communication system design considerations, including data transmission requirements for a nuclear facility and transducer operating conditions. A viable candidate for acoustic communication channel is a chemical volume control system (CVCS) stainless steel pipe, which penetrates through the containment building wall. A laboratory bench-scale system consisting of a nuclear grade CVCS-like pipe and ultrasonic transducers was assembled for a preliminary communication system analysis. Because of low bandwidth and spectral dispersion of ultrasonic transducers, on off keying (OOK) protocol was chosen for data communication. Laboratory tests have shown the acoustic communication system to be resilient to low frequency noise, such as process noise at a nuclear facility. Amplitude shift keying (ASK) communication protocol was developed using GNURadio software environment, and demonstration of data transmission was performed using piezo-electric (PZT) and electromagnetic acoustic (EMAT) transducers. Main achievements thus far include demonstration of transmission of sound and text files with PZT and EMAT across six-foot long nuclear grade stainless steel pipe, and demonstration of image transmission with PZT over the pipe. In the former example, 32KB image was transmitted at 2Kb/s bitrate. Efforts are currently under way to further enhance data transmission rate.