In an article published in several European newspapers, documentary-maker Yosri Fouda said Khalid Sheikh Mohammed and Ramzi Binalshibh told him they had decided against the attack on nuclear power plants "for the moment" because of fears it could "get out of control".
Both men are on the FBI's most wanted list and have a $25m bounty on their heads.
The FBI says Khalid Sheikh Mohammed is one of Bin Laden's key lieutenants, while Ramzi Binalshibh is said to have shared an apartment in Hamburg with Mohammed Atta, the alleged ringleader of the hijackers.