A neutron-gamma mixed-field dosimetry system based on a single lithium fluoride thermoluminescence dosimeter (TLD-700) was developed. The system's ability to perform in the mixed thermal neutron-gamma field of the lead/bismuth irradiation facility at the Ohio State University Research Reactor was then evaluated. Such a system is needed to gather accurate dosimetry data for radiobiology experiments which are performed in the lead/bismuth facility. The system was found to be inadequate for the purpose of measuring both dose components in the irradiation facility. In that environment, the system's response to the gamma radiation is obscured by the response to neutron radiation. A sensitivity analysis was performed to estimate the system's performance under different conditions, in order to determine the condition for which the system is useful for resolving both the gamma and the neutron components of the dose. The analysis suggested that the system might function properly under the following two situations: 1) If a lithium fluoride TLD could be produced with a much lower 6Li enrichment (∼ 0.001%), then the neutron sensitivity would be reduced enough to allow the gamma response to be seen; 2) The same system could be used in a radiation field containing a much lower neutron-to-gamma absorbed dose ratio ( D n/ D g ≈ 0.1). This type of field might be found at other facilities.