There were other things. The diagram, for starters. Aside from being truly rough, it was anything but a nuclear weapon. Definitely not one of Vishkov’s designs because it had no chance of exploding. There was no core. There was no compression system. It resembled a semi sphere, flat side down, with four short cylindrical plugs rising from its top at mild angles. No dimensions were given, and no materials identified.
What is it? he asked himself, over and over. Joe couldn’t figure it out, not without more information. The world of nuclear weaponry did not work in an atmosphere of unknowns and variables. Guesses weren’t his area of expertise.
A buzzer sounded in the cabin, causing Joe to look up. Nothing caught his attention, so he returned to his thoughts, examining the diagram in detail, not with his eyes, but in his mind. His eyes were shut, and the paper’s edge was pressed between his fingers. One comer was bunched up already, worn and crumpled as if soon to be discarded. It might soon be, Joe thought, as it was worthless as far as he could tell.
“Anderson.” Joe hadn’t seen the major approach. “You’re wanted in the com suite. Up forward.”
There was a look in the major’s eyes. Not fear. Not anger. Joe knew he had been a bastard, but that was his way and he never apologized for being himself. If the look was more of distaste it would not have surprised him, but it was not. It was one of single-mindedness, like the man he was looking through didn’t matter. “Where again?” Joe stood.
“Forward. Back of the flight deck.”
Joe worked his way past the Humvees and the gear, then up the ladder like stairs.
The communications officer handed him a bulky headset, which he wiggled into more than put on. “This is Anderson.”
“Anderson, this is Bud DiContino.” The transmission was nearly static-free. “We just received some further information you can probably use. Ready to copy?”
“Go ahead.”
The pause before the words brought static. “We’ve just confirmed that the Libyans took delivery of four hundred and twenty pounds of eighty-one-percent-enriched U235 just over three years ago. This is confirmed and very hot.”
“Where?”
“Osirak. Some salvage company was hired by the Libyans to haul away scrap from the reactor complex. Another source inside the terrorist network gave us the numbers. That came directly from Sadr, but you are the only one to know that. Both of these things put together lead to only one thing: The Libyans bought the fuel and arranged for it to be shipped under cover back home.”
“The fuel cells weren’t supposed to be at the complex,” Joe said. “That’s the only reason the Israelis hit it, because it was cold. They wouldn’t have risked irradiating Baghdad. Are you sure of this?”
“Positive. We confirmed the source of the transfer, and where the money came from.” And a lot more.
“I still don’t believe it’s a bomb, DiContino.”
“You’re right.”
What? “You lost me.”
“We were able to get good answers to your questions. Each of those crates contains a thermal reactor. Make sense?”
All at once it did. “Dammit and dear God. They don’t have to build a bomb out of the stuff — they just have to bring it to critical mass.” Joe did some simple and quick calculations in his head. “Four hundred pounds is enough for twelve critical masses, three per device…”
Bud had cut the number in a third, intentionally. It was a security issue, one that he hoped they would deal with right for once. “Device?”
“That sketch is a simple catastrophic thermal reactor. Each of those four cylinders on top of each half sphere is a chute. If the division of fissile material is even and uniform among the sixteen chutes — four per device— then about twenty-five and a half pounds of U235, three fourths of a critical mass, would be in each one. It’s so simple.” Joe squeezed the coiled headset cord tight in his fist. “Any one of the chutes dropping its contents into the reactor core would create nothing. But two, or three, or all of them dropping would be enough for a self sustaining chain reaction. If all four of them drop into the core there will be so many neutrons releasing that the pile will heat up and melt down in less than three minutes. And if it starts fissioning, there’s not a damn thing I can do about it.”
The communications officer was staring up at Joe. He couldn’t hear the other side of the conversation, but this side was scary enough. Joe rotated his body away from the crewman.
“What happens if these things go critical while the aircraft is still at altitude?”
“Did you ever hear of the nuclear bomber project?” Joe asked.
“Seventies, right?”
“No, that was the earlier concept. In the early eighties there was talk of using nuclear power for long-endurance aircraft. It was supposed to use reactor power for cruising at altitude and regular jets for takeoff and penetration.”
“SUMMIT,” Bud said, remembering the project that eventually ended up in the concept scrap heap.
“Right. We did some studies for the Air Force on the effects of a catastrophic reactor failure in flight, fairly similar to what you’re asking about. If one of those things goes critical and melts down, this is what will happen: The core of U235 will melt through the core liner first, then the cargo-hold floor, and finally the outer skin of the plane. In itself that’s going to release a hell of a lot of nucleides into the atmosphere. Those are the isotopes of the different metals that will be liberated when it melts. As soon as the piles melt through and hit the air, any moisture is going to turn to steam, because all we have are four lumps of molten uranium. Anything that contacts them is instantly vaporized or reduced to its own molten state. Then we have the good news/bad news syndrome: Because the piles would be beyond red-hot they wouldn’t be very cohesive as a structure, so on the way to the ground they’d break into several pieces, which would each start to cool rapidly. Without a proper mass structure the chain reaction will stop — no reaction, no heat. The fuel source may have been enriched only in a powdered form, then compressed; that’s what Osirak was supposed to be fueled with, and it’s a higher concentration than Tajoura’s fuel. Once that stuff melts, cools, hits the ground, and is cooled further, you’ll have a gravelly, metallic consistency with some ash like by-products. Depending on the altitude of release the area of contamination could be as large as, say, six hundred square miles. There would be several very hot spots and a whole lot of widespread hot spots that would pose severe health risks. Some of the hotter areas would be putting out on the order of four hundred rems, enough to kill half the people who come in contact with the area. All in all, DiContino, it would be a major mess, way off the scale of anything we, or anyone else, have ever had to deal with.”
“Well, that’s precisely what the terrorists plan to do — right above Washington.”
“You’re crazy!”
“No, but they may be. We’ve pretty much confirmed it. You’re the fireman on this one, just like before.”
Joe had hoped never to repeat anything like that. “It was in a little different setting.”
“True, but I’m certain of your adaptability,” Bud said. It was a statement of fact, and a challenge.
Sure. “The hijackers are just going to lay down their guns — you’ve confirmed that, right? Look, that aircraft cannot be allowed over any populated area.”