The on-line and process radiation monitoring capability at the Barnwell Nuclear Fuel Plant has been evaluated. Experiments have been performed to test the monitors’ capability to assay plant streams. Several of the monitors have been subjected to evaluation experiments in the laboratory to determine sensitivity, accuracy, reliability, and overall system performance. The incorporation of many of these monitors into a real-time or near-real-time material control system is under way. Many of the monitors have been tested for operability in situ and the results of these tests indicate satisfactory performance over the intended sensitivity ranges. An effort is under way to develop new nondestructive assay techniques for on-line monitoring of special nuclear materials present in the process streams of a nuclear fuel reprocessing plant.