U-235 but requires complex lenses and initiators.

During the initial months of the occupation, Tuwaitha was protected by American forces and administered by contractors from the Raytheon Corporation. Complete control of the facility was turned over to Iraqi authorities in the Summer of 2004. During American occupation the complex was looted, mostly for scrap lead. Lead-lined barrels and containers were emptied on-site then taken to a nearby improvised lead foundry then smelted into ingots.