Exit Plan Read Free Page A

either from foreign agents or someone inside.”
     
    “It’s hard to prove the absence of something,” Moradi offered.
     
    Rahim pulled out a notepad and flipped through the pages. “This is already one of the most secure installations in Iran. My people have enhanced those measures. We’ve been able to correlate the movements of everyone on base that day with the entrance and exit logs for each building. Dr. Sabet has helped us with scenarios for sabotage, and who would have the knowledge to perform it. Everyone on the list is being watched. Most have been questioned.”
     
    Moradi nodded as he took in the information. He’d expected this result. If Rahim had found anything amiss, the perpetrators would have been arrested instantly. VEVAK might have different masters than the Shah’s SAVAK, but they used the same methods.
     
    “Could it have been that damned computer worm again?”
     
    “Unlikely, sir. I had every computer on the installation checked, as well as all personal computers in the dormitories. Every CD and flash drive was also examined. There was no sign of the Stuxnet worm. As you recall, we found this worm on dozens of computers when the cyber attack was first discovered three years ago,” remarked Rahim.
     
    Stuxnet was a devilishly effective piece of malware that sought out and attacked the motor controllers on the centrifuges, causing them to undergo wild variations in speed. This greatly reduced an infected centrifuge’s performance, and even caused damage to the main support bearing. But even though the worm destroyed itself after completing its dirty work, numerous computers were infected as the malware worked its way from its original source to the centrifuges.
     
    “Have any of the staff suffered a family tragedy, or had some other personal crisis?” Moradi knew he was reaching, but he had to ask.
     
    Rahim shook his head. “No, sir. I’ve reviewed the local security officer’s records, and confirmed their accuracy with my own sources, as well as the reliability of the officers themselves.”
     
    “Thank you, Major. You’ve removed the possibility of malign influence. Unfortunately, that would have been the simpler answer.”
     
    The next meeting was the important one, with the physicists and engineers who had failed in their fourth attempt to create an improved centrifuge design. Iran had built a working centrifuge, but it was primitive, “first-generation” technology, and it was based on a design provided by a Pakistani nuclear scientist, A. CX Khan. Centrifuges separated two uranium isotopes from each another by spinning uranium hexafluoride gas at tens of thousands of revolutions per minute. One isotope, U-238, was marginally heavier than the other, more desirable U-235. The difference of three neutrons pushed the heavier, unwanted U-238 toward the outside. The gas near the center, slightly richer in U-235, was removed.
     
    But the increase was infinitesimal. Natural uranium contained less than 1% U-235 by weight. This had to be increased to about 4% to be used as reactor fuel, and to 90% for a weapon. And each centrifuge only enriched the gas by a few hundreds of a percent.
     
    So the centrifuges were ganged together, each one taking the product of the one before and increasing the concentration of U-235 by some tiny amount. The sixty-four-centrifuge test cascade that had torn itself apart produced a trivial increase. The buried halls at Natanz had thousands of centrifuges installed in series, but even then the product had only just exceeded 4% thus far.
     
    And that was the problem. It was taking too long to produce even small amounts of reactor-grade material. Iran needed to move quickly from reactor-grade to weapons-grade levels, and in large quantities. They could not build just one bomb. They needed several, at least a half dozen, to have a viable nuclear weapons capability.
     
    Unfortunately, the Pakistani first-generation centrifuge design was inherently