The British were kept out of the loop, being told at different times that the huge construction site was a desert grasslands research institute and a manganese processing plant. The Americans, also kept in the dark by both Israel and France, flew U2 spy planes over Dimona in an attempt to find out what they were up to.The Israelis admitted to having a reactor but insisted it was for entirely peaceful purposes. The spent fuel was sent to France for reprocessing, they claimed, even providing film footage of it being supposedly being loaded onto French freighters. Throughout the 60s it flatly denied the existence of the underground reprocessing plant in Dimona that was churning out plutonium for bombs.

The truth about Israel's secret nuclear arsenal | World news | The Guardian Sunday, January 19, 2014 @ 3:25pm