Hydrogen Generation from α Radiolysis of Organic Materials in Transuranic Waste. Comparison Between Experimental Data and STORAGE Calculations

The Alternative Energies and Atomic Energy Commission and Orano have developed a modeling tool named the Simulation Tool Of RAdiolysis Gas Emission (STORAGE) for assessing gas generation of intermediate-level waste. The first version of this model was designed to estimate gas (more specifically hydrogen) generation by radiolysis of organic materials contained in waste packages.

To verify the validity of the model, a series of measurements was performed on U, Pu–contaminated solid waste issued from the Orano plutonium laboratories at the MELOX facility. Twenty-one drums containing technological waste (gloves, bags, filters, metallic parts, etc.) packaged inside polyvinyl chloride sleeves were set up and hydrogen production was measured over a period of more than 1 year. Several levels of contamination and organic content were studied.

STORAGE calculations are conservative and most of the time in good agreement with experimental measurements with the uncertainties. As expected, the simplest cases (organic waste or filtering media) are well described by the model. The data are obviously more widely dispersed when the waste is composed of a mixture of organic materials and metal. Nevertheless, an understanding of the waste (package composition) allows a fairly precise description and ultimately a satisfactory estimation of the hydrogen production rate.