A non-negligible fraction of the costs were hidden because the army paid for it in order to obtain, build and maintain atomic weapons. The French Court of audi

A non-negligible fraction of the costs were hidden because the army paid for it in order to obtain, build and maintain atomic weapons. The French Court of audit (Cour des comptes) could not establish it, and had to guesstimate. The need for such weapons diminishes and transparency is getting better and better, therefore this trick is becoming obsolete.