Binding Heads of Agreement covers a test bench and a commercial-scale plant at Pelindaba, home to Necsa's 20 MW SAFARI-1 research reactor.
Funded with about $95 million cash on hand and $21 million of equity, and expected to be accretive to adjusted earnings per share in the first year.
Seven test facilities are already operational at the Chusclan site near Marcoule, with further installations under development.
Each pebble gets three data matrix codes etched half a millimeter deep by infrared laser, linking it to a record of its dimensions and density.