8.4 (2012)

by Peter Hernon

  “Whatever you need will be made available,” Carson said tersely. He asked what kind of weapon they wanted.

  “One of the MK/B-61s,” Booker said. “It’s a superb warhead. Many of them are still in service. The cruise missiles use your basic MK/B-61. Excellent safing components and a superb hard case.” One of the larger weapons still in use, the bomb came in four configurations, ranging from a 500-kiloton yield up to one megaton. It was designed so that the yield and fusing could be programmed in flight.

  Carson sat down at his desk and tapped a few keys on a computer terminal. “We have more than a hundred of those warheads in storage in Building 12-11.” He printed out a sheet of paper and handed it to Booker. “The manifest lists the dates of disassembly. May I ask what yield we’re talking about?”

  “One megaton, maybe a little more if we have to boost it,” Booker said. “Right now we’re not sure.”

  The debate on what size weapon to use was still raging in Memphis. Atkins hoped to hear soon from Guy Thompson, whose team had been crunching numbers around the clock, trying to calculate the maximum yield and where to place the weapon. They were playing a deadly balancing act. Atkins wasn’t sure that clear-cut, definitive answers existed. No matter what they did, it was going to be a huge gamble. At times he thought the only thing that came close to explaining what they were up against was Chaos Theory, the notion of the importance of randomness in the universe.

  Carson drove them to one of the igloos. A truck-sized forklift rolled away the twenty-five-ton concrete barrier that blocked the entrance. Punching a code into a keypad, he unlocked a pair of steel blast doors that opened automatically. They entered a bunker that roughly resembled a Quonset hut in shape. The arched roof was fifteen feet high. A pair of tracks ran down the middle of the floor.

  “The walls are made of corrugated steel two inches thick,” Carson said. “On the outside, they’re banked with six feet of dirt.”

  Fascinated, Atkins watched as a tractor operated by remote control rolled down the tracks and removed one of two dozen stainless steel drums stored on a metal rack that ran the length of the wall. The drum contained the “pit” or nuclear package of an MK/B-61 weapon that had been retired five years earlier.

  Carson placed a small handheld instrument that resembled a photographer’s light meter next to the steel canister. “This is a spectrograph,” he explained for Atkins’ benefit. “Each one of these bombs has its own electronic fingerprint. This tells me we’ve got the right one.”

  The tractor loaded the canister on the forklift. Within minutes they were headed to Building 12-11, one of the Gravel Gerties. After Carson opened the double doors, again with a special keypad, Atkins stepped into a tunnel that intersected with a labyrinth of other long passageways.

  “Where to now?” he asked Booker, who was striding ahead of him. The physicist looked completely at home.

  “The X-ray cell.”

  A guard had them place their right hands on a glass-surfaced scanner. The reading was automatically compared with a similar scan taken when they’d first arrived at the plant. They were ushered through a steel door into a wedge-shaped space outfitted with a turntable and CAT scanner. The weapon’s nuclear package had already been removed from the stainless steel canister and placed on the turntable.

  “That’s all there is to it?” Atkins asked, staring incredulously at the cylindrical device. About four feet long, it was barely a foot and a half in diameter.

  Booker grinned. “That may not look like much, but it makes a hell of a bang. Its compact size makes it perfect for an underground explosion. When I’m finished, we’ll put it back in its hard case. It’s got one of the best subassembly designs I’ve ever seen. A series of polyurethane spacers absorb shock and support all the internal components. It was designed to slam into the ground and still go off.”

  Seated at a computer terminal above the turntable, Booker carefully examined the CAT-scan images of the pit. The X-rays showed diagonal slices of the weapon. For security reasons, Atkins wasn’t allowed to watch. He knew that Booker was inspecting the weapon’s nuclear components, namely the plutonium-239 in the primary and the lithium deuteride uranium in the secondary.

  Booker had explained the physics. When the secondary implodes, the lithium converts to tritium, which, in turn, undergoes fusion with the deuterium to create the thermonuclear blast.

  After nearly an hour hunched over the computer screen, Booker pronounced the nuclear package fit.

  “Now comes the tricky part,” he said.

  Atkins understood. Booker had to install the double layer of high explosives that were bonded with plastic so they could be shaped. The explosives and detonators surrounded the weapon’s pit. When this material exploded, it started the implosion process, compressing the plutonium to a supercritical mass. The amount and type of high explosives used in the weapon was a carefully guarded secret.

  They took an elevator to a lower level, where Booker would work alone on the explosives in a space that reminded Atkins of an operating room—all bright lights, gleaming tile, and stainless steel. Booker put on a heavy lead apron, gloves, and a facemask to protect himself from any radioactive emissions from the pit. He also wore antistatic booties.

  “I helped develop the explosive,” he said. “I wish I could tell you about it. Wonderful stuff. A mixture of PETN, C4, and some other goodies.”

  Atkins knew that C4 consisted of TNT plus a plasticizer and had the consistency of putty. It was fashioned into precisely cut “lenses” and carefully fitted around the plutonium pit. The lens design, one of the great breakthroughs of the Manhattan Project, controlled the explosion, shaping the blast to flow inward and set off the required implosion. The explosives were already cut and available. But it would take Booker several hours to position them and install the detonators and fuses.

  “Come back in two hours,” he said. “If my legs don’t give out, I ought to be finished by then.” He entered the operating room through another pair of air-locked steel doors.

  At the plant manager’s invitation, Atkins rode with him to his office.

  There was news from Memphis.

  Guy Thompson was calling on a satellite hookup.

  “We’ve got it pretty well nailed,” Thompson said. In his excitement, he spoke too fast and Atkins had to slow him down. “A one-megaton underground explosion would approximately equal an earthquake in the magnitude 6.5 range, maybe a little less.”

  “What distance are we talking about?” Atkins asked.

  “Maximum intensity up to twenty-six to thirty miles,” Thompson said. “We’ve done some wave-form modeling that suggests a one-megaton explosion would release large amounts of tectonic strain energy.”

  The estimate, he explained, was based on the results of the 1969 Milrow shot, the second of three underground explosions conducted in the late 1960s and early 1970s near Alaska in the Aleutians. One of the key indicators was the amplitude of Love waves such a blast produced. Love waves—seismic surface waves with a horizontal shear motion—were evidence of the release of tectonic strain energy. The more waves picked up by seismographs, the greater the tectonic release.

  “The Love waves from Milrow were incredible,” Thompson said. “It produced a main earthquake of magnitude 6.5 and dozens of aftershocks in the magnitude 3 and 4 range.”

  “How deep did they set it off?”

  “Thirteen hundred meters,” Thompson said. “And there was absolutely no triggering of large earthquakes along other faults in the area.” That had been a major worry because it was one of the world’s most active plate boundaries. The seismic behavior was virtually identical on the other Aleutian blasts—Longshot in 1965 and Cannikin in late 1971.

  Atkins almost shouted out loud. That was good, good news. The fear that a nuclear shot in the New Madrid Seismic Zone would trigger quakes on other faults was everyone’s nightmare. Here was solid evidence that it hadn’t happened before.

  His fear all along had been that
a nuclear explosion might set off a chain reaction on other faults. There was no question in his mind they had to try something. The stakes were too horrendously high. A big quake was a virtual certainty. He was resigned to Booker’s nuclear explosion, but he’d been worried sick about the risks.

  Now some of that fear had been lifted. He began to think that they might be able to stop the earthquake cycle, or at least slow it down.

  “The only problem is the depth of the shot,” Thompson said. All right, here it comes, Atkins told himself. He was saving the bad news for last.

  “Everyone agrees we’ve got to get lower than thirteen hundred meters for maximum effect,” Thompson said. “The Caruthersville Fault is about eighteen miles down. The closer we can get to it, the better.”

  That sure as hell eliminates boreholes, Atkins thought. It would take weeks to drill down that far. They didn’t have that kind of time.

  “We’ve got one option.” Thompson said. “There’s an abandoned coal mine within five miles of the place where the Caruthersville Fault intersects with the New Madrid Seismic Zone and the fault that opened up after the 7.1 earthquake. It’s two thousand feet deep.”

  Atkins understood why the mine was perfectly located for their purposes. Seismic stress was most likely concentrated at the ends of a fault or at the point where one intersected with another. The two newly discovered faults and the eastern edge of the New Madrid system all came together in roughly the same area.

  The mine was near that bull’s-eye.

  “We’re trying to get a team there to scout it out. Right now it looks like the best site. Walt Jacobs tells me you’ve already been there. It’s called the Golden Orient.”

  Atkins remembered their trip to the mine—how frightened he’d been from start to finish.

  “John, are you all right?”

  Atkins was aware of Guy Thompson’s voice on the other end of the line. He noticed how the plant manager was watching him.

  “I’m fine,” he said. He was lying. He didn’t want to have anything to do with that mine. But the issue was already settled. They had to explode the bomb at depth. The mine was their only option.

  He was going to have to go down there again.

  At the mention of Jacobs’ name, he wondered how his old friend was doing. He continued to worry about Jacobs and his ability to cope with the loss of his wife and daughter and still do his job. The man needed professional help.

  Atkins quietly asked about Elizabeth Holleran. He’d had no idea when he left for Texas how much he’d miss her, or how often he’d find himself thinking about her.

  It was Guy Thompson’s turn to fall silent. He hesitated before he said, “Something’s happened, John. She’s all right. We’ll talk about it when you get back. We had some trouble with our equipment.”

  MEMPHIS

  JANUARY 19

  6:30 A.M.

  ELIZABETH WASN’T SURE HE UNDERSTOOD HER, or that he was even listening.

  “Walt, did you hear what I just said? Someone stole my laptop. It had to be the same person who turned off the emergency generator. It happened at the same time.”

  Elizabeth Holleran had gone to Walt Jacobs’ partitioned workspace after catching several hours of sleep in the equipment room. This time she’d kept the door locked. The sun had just come up. She’d found Jacobs sitting at his desk, staring at printouts of seismograms from aftershocks that continued to occur along the new Caruthersville Fault. The activity hadn’t slowed.

  Jacobs looked up as if hearing her for the first time.

  “Someone … stole your computer?” He sounded incredulous.

  “In the equipment room. When the power was out.”

  Elizabeth spoke softly. They were in the library annex. Across a hallway, Guy Thompson and some of his people were feverishly working at an array of computer terminals, trying to calculate the seismic effects of underground nuclear explosions. They’d worked right through the night. Thanks to the president, Thompson had four new high-speed computers to help them crunch numbers. He’d brought the machines back from Washington. Fortunately, they hadn’t sustained any irreparable harm when the generator went out. They’d lost some real-time seismic data on the aftershocks but had arranged to have it retransmitted.

  Anger had replaced Elizabeth’s shock. She regretted she hadn’t gotten a good look at the thief. She couldn’t even guess his size or weight and was upset with herself for not reacting more quickly. She’d let him get away.

  Elizabeth had already told Thompson, someone she knew she could trust completely. Then she’d gone to Jacobs, who listened quietly as she described what had happened. He seemed distracted.

  Before leaving for Texas, Atkins had told Elizabeth about Jacobs’ wife and daughter.

  She wanted to respect the man’s need for privacy to deal with his grief and would have preferred not bothering him at all. That’s why she’d initially gone to Thompson, but Jacobs was in charge of the lab. He had to know.

  She wished Atkins were back. She needed to talk to him, to be close to him. She admitted to herself for the first time that she was falling in love with him. It was a strong, warm feeling and one she didn’t want to lose.

  A single fact haunted her. The man who’d entered her room had to be someone who worked at the annex and knew she slept alone, someone she’d seen before. One of the scientists. Someone who knew her movements and was probably still in the building, keeping an eye on her.

  Guy Thompson was sure that it was deliberate sabotage by the same person who’d turned off the generators. In his opinion, someone wanted to shut down or steal as many computers as possible to create confusion.

  “It’s got to be someone who doesn’t want us to set off that bomb,” he’d said. “What other motive could there be?”

  Elizabeth wasn’t convinced, if only because she found it almost impossible to believe any of the scientists at the center would go to such lengths. And even if they had, most of them, Jacobs included, had expressed serious doubts about setting off a nuclear bomb underground. So who was it?

  She repeated Thompson’s comments to Jacobs, who kept staring through her. It was creepy. As if she weren’t there.

  Finally, he seemed to snap out of it. But when he spoke, it wasn’t about what she’d just told him.

  “We can’t do it,” he said, fixing his deep-set eyes on her. “We can’t set off a nuclear bomb near an active fault.”

  AMARILLO, TEXAS

  JANUARY 19

  12:20 P.M.

  IT TOOK BOOKER NEARLY THREE HOURS TO complete the delicate task of affixing the bonded outer layer of high explosives and detonators to the MK/B-61’s nuclear package. Working alone in the “operating room” cell deep in one of the Pantex plant’s Gravel Gerties, he was halfway through the procedure when Atkins told him by telephone hookup that they’d decided to go for a one-megaton shot.

  “Consider it done,” the physicist said.

  Compared with layering the high explosives, setting the yield was a simple procedure. By injecting a sufficient quantity of tritium-deuterium gas into the plutonium pit, Booker was able to boost the bomb’s yield from 500 kilotons to just over one megaton. The implosion process would heat the gas to the point where its atoms underwent fusion. The result was a jolt of high energy neutrons that produced the extra bang.

  Booker finished up by using an overhead hoist to slip the nuclear package back into the missile’s center subassembly, its “hard case.” The unit contained an array of timers, electronic fusing, and firing circuitry. Weighing less than four “hundred pounds, the bomb resembled an elongated, slimmed-down trash can made of gleaming stainless steel.

  Booker was drenched with sweat when he took off the lead apron and stepped into the hallway. The steel blast door clicked shut behind him. Atkins told him that Guy Thompson and other seismologists back in Memphis had recommended detonating the bomb in an abandoned coalmine.

  “How deep?” Booker asked.

  “About two thousand fee
t. I’ve been there. It’s a vertical shaft mine with two air vents.”

  “Good. I can work with that,” Booker said. “But we’ll have to worry about venting.”

  Atkins knew that was one of the main risks of an underground explosion, the possibility that radioactive debris and gases would escape into the atmosphere, venting from cracks that blew open in the ground.

  It had happened before—sometimes with disastrous consequences. Massive amounts of “hot” dust, soot, and gas had contaminated the earth’s atmosphere.

  One of the worst accidents, Booker explained, happened during a test code-named “Baneberry.” The device was detonated in December 1970 at the Nevada Test Site sixty-five miles northwest of Las Vegas. Booker had been there.

  It was a relatively small shot—ten kilotons. At zero hour, the moment they fired the weapon, Booker had been sitting in the “red shack,” the control room three miles from the test site.

  “The hole was too shallow. Only about five hundred feet deep. We’d stemmed it with sand and gravel after wiring the bomb. When it went off, I was watching the television monitors. You could see the ground ripple up and down as the shock wave moved toward us. It pitched us up in our chairs. Then all hell broke loose.”

  The explosion ripped a gaping hole in the desert floor and sent a cloud of radioactive gas eight thousand feet into the sky. The cloud drifted as far as North Dakota.

  “We’ll have to figure out how to collapse those air tunnels and the elevator shaft,” Booker said. “We won’t have time to backfill them.” He looked at Atkins. “This is going to be tricky.”

  “How will you detonate the bomb?” Atkins asked.

  “We used cable with all of our underground shots at the NTS,” Booker said. “That’s out of the question. The ground’s too active. One good earthquake, and the cable could snap.” He considered the options. “We might try a radio signal, but I’d worry about all the deflection—bouncing the microwave beam down a mine shaft.” He thought some more. “I’d opt for a timed charge.”