Reaction between plutonium and deuterium. Part II. Rate measurements by weight changes

The effects of pressure and temperature upon the rate and mechanism of the reaction between plutonium and deuterium have been studied for temperatures to 4000C at pressures from 1 to 15 kPa. The rate was determined by measuring the weight changes of plutonium disks as the reaction proceeded. Below 2000C the reaction product spalled to expose fresh metal. The equation R = k/sub T/AP0.6 fits the data, where the rate R is the milliequivalents of deuterium reacting per hour, A is the geometrical surface area, P is the deuterium pressure, and k/sub T/ is the velocity constant at temperature T. The energy of activation for the spalling reaction is 5.9 kcal . mol-1 for PuD2.7. Between 250 and 4000C the product adhered to the parent metal to form a growing layer. The equation R = k/sub T/*AP/ΔW fits the rate data, where R, A, and P are defined above, ΔW is the measured weight change in milliequivalents of deuterium, and k/sub T/* is the velocity constant at temperature T