Randomly packed beds of ceramic pebbles are a practical approach to ceramic breeder blankets. This paper examines various models for the heat transfer through such beds. While many models are acceptable for some blanket conditions and single-sized ceramic pebbles, the full range of interest requires some modifications. In this study, the models are examined, modified and compared with fusion-relevant data. A modified form of the Schlunder, Zehner and Bauer model is recommended for both bulk bed thermal conductivity and for the near-wall interface region.