MSSS OBLM Chemical additives to Silo

The Magnox Swarf Storage Silos (MSSS) were designed to store Magnox swarf residues underwater in a series of silo compartments. The liquor in MSSS is not routinely purged. Instead, additions have been made historically to offset losses due to evaporation and occasional liquor transfers, so that the liquor level is maintained. In 2019, there was an increase in the requirement for water top up in the OB. This was associated with a leak to ground. The extent of the leak has stabilised but frequent addition of water is...