Study of gas generation in real L/ILW containers

Abstract

To obtain reliable estimates of the quantities and rates of the gas production in L/ILW a series of measure- ments was carried in the last 7 years in Hungary. The typical gas production rates were 0.05-0.2 STP litre gas/day for CO2 and CH4 generation, and less for H2. No explosive gas mixture was indicated in the L/ILW drums during the investigated storage period. Compositions of headspace gases in closed L/ILW vaults were in agreement with gas generation processes observed in L/ILW drums. The stable carbon isotope measurements show that the main source of the CO2 gas is the degradation of organic matter and indi- cates microbial degradation processes as the main sources of CH4. Typical tritium activity concentrations were\10 Bq/l gas in the drums and\1,000 Bq/l gas in the vaults. Typical 14 C activity values of the headspace gases were \2.0 Bq/l gas in the drums and\1,000 Bq/l gas in the vaults.