A realistic estimate of the interionic potential that may account for the experimentally observed fusion rates (≈10−23 deuterium-deuterium fusion/s) in palladium is presented. Moreover, some preliminary calorimetric studies on the hydrogen absorption process in palladium, performed in a cell with pressure up to 20 bars, are discussed. A detailed analysis of the sensitivity and calibration of the calorimetric system is also presented.