Development of a Demountable In-line Plutonium Calorimeter

A new high sensitivity demountable in-line calorimeter has been developed in order to overcome the problems of servicing and decommissioning conventional in-line calorimeter systems. The device is mounted on a solid aluminium glovebox well extension, which maintains the containment of the glovebox environment. This extension forms a passive inner component to the calorimeter measurement chamber. It is close coupled to a demountable thermal element which contains all of the temperature measuring and power delivery electrical circuitry. This demountable component is readily mounted and removed from the glovebox extension. Two prototype instruments have been developed which exhibit high sensitivity and base power stability. Efficient and simple sample loading arrangements are employed and measurements have been undertaken on a variety of plutonium samples. The calorimeter has extensive self test and diagnostic capabilities as well as internal electrical calibration. Results of live sample measurements are presented in the paper.