“You measure the power of atomic bombs in coal?”
“No, actually. We measure the power of bombs in tons of high explosive. TNT, to be precise. It’s not really a scientific metric, but it’s a more useful indicator than energy content when you are measuring the impact of the device on the real…um, world. For instance the first American device, Little Boy, dropped on Hiroshima in ’forty-five, yielded eighteen kilotons. The same as dropping eighteen thousand tons of high explosives at the same time.”
“My God.”
“Little Boy was tiny by modern standards.” Axelrod straightened with pride. “The detonator alone for RDS-220 is a fission bomb larger than Little Boy.”
“A detonator as powerful as eighteen thousand tons of TNT?”
“We talked about fission, splitting atoms. When you put a certain amount of U-235 in one place, the radiation, the neutrons coming off all those disintegrating atoms start to split each other apart. Like rolling a billiard ball into a cluster of other billiard balls. Free neutrons knock out other neutrons, which knock out others. That reaction also gives off heat, and more neutrons, which in turn split more of the surrounding atoms in a spontaneous chain reaction. That’s what happens in a nuclear reactor. You put enough fuel in, and it starts to generate heat on its own.”
“You mean it starts to destroy itself spontaneously?”
“Right. But you can control the reaction by absorbing those free neutrons with graphite rods. It’s like putting a dishcloth on the billiard table. Some of the balls will roll into it and stop knocking each other around. With graphite, we can control the reaction and stop a nuclear reactor from melting down. We’ve even been putting reactors in submarines. Kit-class attack subs to start off with, in ’fifty-nine. And last year we launched the first nuclear-powered missile sub. There have been some problems, though. Back in July there was a terrible accident on K-19 out in the North Atlantic—the reactor coolant leaked, and the crew have been dying like flies ever since….”
“For God’s sake, Axelrod. Do you even know the meaning of the word secret? One more word about submarines and I’ll have to bury you myself.”
Axelrod’s face tightened anxiously for a second as he weighed whether Vasin was joking, then relaxed into a nervous smile. “An atom bomb uses the same principle as a nuclear reactor. A fission reaction. But instead, it’s designed to melt down on command, explosively. To do that you need to focus the reaction.”
“How?”
“If you just put a pile of blocks of uranium 235 together, they’ll start to react as soon as you have a critical mass. Takes about fifteen kilos of pure 235. It will get hotter and hotter and emit more and more radiation. But it won’t explode. You’d just get a kind of nuclear bonfire that would burn through the floor. And probably though the earth’s crust. Nobody’s tried it….”
Axelrod paused for a moment, as though considering how interesting such an experiment would be.
“And how does it go bang?”
“So, to get it to explode, we need to achieve critical mass very suddenly, and under great pressure. That means we have to enclose the reaction in some kind of vessel. That’s called the tamper. And we need a way to transport the critical mass of uranium in a safe state until you’re ready to detonate it. Actually, the answer is very simple.”
The scientist glanced questioningly at Vasin, as though at a particularly unpromising student. “Obvious, really.”
Vasin spread his hands with a gesture that said, No idea.
“You cast the uranium 235 into a hollow ball.” Axelrod cupped his hands to imitate a sphere. “The critical mass is all there, but there’s not enough of it in one place to trigger a chain reaction. It doesn’t go critical on its own because it’s hollow in the middle, you see? It’s too spaced out.”
“And then?”
“Then you surround this hollow ball with an outer shell of explosives. You detonate those explosives and the blast makes that ball implode.” He squeezed his cupped hands into a tight fist. “Suddenly, it’s a solid ball and therefore goes critical. A chain reaction kicks off and energy is released. Nuclear explosion.”
“That’s what happens inside that?” Vasin pointed to the file on the desk.
“Yes. No. I mean, both. RDS-220 isn’t like an old-fashioned fission bomb. It’s a thermonuclear device. A hydrogen bomb, in common parlance.”
“Which is?”
“Very different. The first atom bombs worked by splitting heavy atoms apart, nuclear fission. Thermonuclear bombs work the opposite way. They make lighter atoms join together. Nuclear fusion. That’s what happens in the heart of the sun, in all stars. They are all giant, continuous thermonuclear explosions. Balls of hydrogen, fusing together to make other elements and giving off light and heat. Every atom in the universe was created inside a star. Every atom in your body, in mine. To reproduce the effect on earth we need to create the same conditions as on the sun. We expose hydrogen to heat and pressure. Something like seventy-three million times the pressure of the atmosphere of earth. And the fusion begins.”
“And how do you make a sun…on earth?”
Axelrod smiled in fond pride, as though Vasin had asked him about the school grades of a particularly brilliant child.
“By using a fission bomb as a detonator, we get the necessary energy. As long as you surround the detonator and the hydrogen in a strong enough casing. The tamper has to be very thick and heavy to withstand the pressure for as long as twenty, maybe thirty milliseconds. Then you get enough energy concentrated inside to start a fusion reaction.”
“Which is explosive?”
“What you call an ‘explosion’ is just rapid combustion. Combustion is something solid turning to gas and expanding. Expose almost anything to enough heat and it will turn into gas. So, when the hydrogen atoms in the bomb fuse together into different elements, they release enormous amounts of heat and light that vaporize everything around them. But that explosion also vaporizes the casing of the bomb itself, releasing the pressure, and the fusion reaction stops. That was the genius of Petrov’s design. The heavier and stronger the tamper, the longer it can contain the fusion.”
“That can happen in twenty thousandths of a second?”
“Certainly. That’s long enough to create a sun. A small sun. And you see, the stronger the tamper you have, the longer the reaction time. Petrov’s idea was to make a casing of twenty tons of pure uranium metal. Very dense. Very strong.”
“Twenty tons of uranium? But you said that fifteen kilos was enough….”
“Fifteen kilos of weapons-grade uranium is enough to make an atomic bomb, yes. That’s uranium 235. But like I said, natural uranium metal contains less than one percent of that stuff. Ninety-nine percent is uranium 238. It is much more stable, but has never been used to make a tamper. We always used lead. But Petrov was a genius, a revolutionary. He wanted to make RDS-220 out of uranium for two reasons. It’s much denser than lead—about twenty tons per cubic meter for uranium, eleven for lead. And uranium’s boiling point is more than twice as high.”
“Stronger tamper, bigger explosion.”
“Correct. Well done.”
“And the other reason?”
“Ah. Here is the pure beauty of Fyodor’s vision.” Axelrod sat forward, his whole body animated. “A new generation of devices, an order of magnitude bigger than anything ever seen before. He wants to open a new chapter.” He caught himself, as though stung. “Wanted.”
“A new chapter of…?”
“Petrov’s idea was a three-stage bomb. The first two stages were a standard hydrogen bomb. A fission device as a detonator, then two chambers of hydrogen as the main explosive force. But the casing itself would act as a third stage. The neutrons thrown off by the fusion would irradiate the uranium tamper. Even the trace amounts of U-235 could become f
issile with that much radiation and heat. So you have three stages: fission, then fusion, then once again fission. The uranium tamper was revolutionary. It would have doubled the power of the device. More, perhaps.”
“Might? Using a uranium casing has never been tried?”
Axelrod shook his head.
“So what did Adamov change?”
“The day after Petrov’s death, Adamov ordered the metallurgists who were casting the uranium tamper to stop. And ever since he’s been closeted night and day with his closest comrades recalibrating. And today—this.”
Axelrod traced a finger over the cover of the thick document that lay between them.
“The new tamper is made of lead. Not uranium, but lead. Which is inert. There is no third-stage fission. Professor Adamov’s substitution of lead for uranium will drastically reduce the power of the device. It is the opposite of what we have been trying to achieve. It’s sabotage, Major.”
“Are you sure?”
“I am quite sure the yield will be reduced.” Axelrod’s voice became low and urgent. “By how much, we won’t know until we calculate the projected yield with an inert casing. I want to get some time on our electronic computer to work out how much.”
“How powerful does it have to be?”
“That’s the point. General Secretary Khrushchev has ordered a one-hundred-megaton device. A hundred million tons of TNT equivalent. Yes. Roughly five thousand times more powerful than the Hiroshima bomb.”
“Fuck.”
It wasn’t often that Vasin was moved to swear. Axelrod glanced up with faint distaste.
“That’s one way to put it. A hundred megatons was meant to put the Americans in their place. Before Adamov began his alterations.”
“Will this device be bigger than the Americans’ bombs?”
“The biggest hydrogen bomb they have ever detonated was about fifteen megatons, but that was by accident. Anyway, the Yankees got scared and started making them smaller.”
“Scared of what?”
Axelrod shrugged.
“I thought it was the kontora’s business to tell us what the Americans are thinking.” He ventured a quick, nervous smile before continuing. “They got scared of the unpredictable effects, I suppose.”
“What unpredictable effects?”
“You wouldn’t understand.”
Vasin ignored the insult.
“You’re saying that maybe Adamov got scared?”
“Soviet scientists fear nothing, Comrade. We fear only fear itself. As the Yankees’ President said once.”
“But isn’t it dangerous to increase the scale so radically?”
“Thermonuclear bombs are quite dangerous, Major.”
“You don’t think that caution in this matter…”
“Cowardice in this matter is a betrayal of the trust placed in us by the Party, Comrade. And deliberate sabotage would be, of course, treason.”
Axelrod spoke with a bravado that was just short of absolute earnest. Ah, thought Vasin. A weak man, flinging words stronger than himself in the hope that someone will believe him. He’d seen the type.
“And who knows about these changes?”
“Everyone. That’s the way we have always worked here. A basic principle of our craft. At the beginning, the kontora, your chief, Beria, tried to impose compartmentalization of information. The Beard—Igor Kurchatov, the builder of our first Soviet device—refused. He insisted that here inside the program we have complete freedom to exchange information. And so it has remained. Therefore, Adamov handed out the new general design today to the heads of all the laboratories. Every senior academic worker has access to his department’s copy.”
“And who knows about the exact implications of Adamov’s change of design?”
“Protopopov, the chief metallurgical engineer. He’ll be kept busy casting the new lead tamper. The rest of the design is pretty much unchanged.”
“Does anyone share your view that Adamov’s plan is sabotage?”
“Every man here owes his advancement to Adamov. They are all his acolytes. For them the Director is the brain of the Institute. He taught them. He made them. They would never question his wisdom and judgment.”
“Except you.”
“Except me. But that is only because Fedya—Dr. Petrov—took me into his confidence over their dispute. Adamov had been worried about the uranium tamper for months. They argued about it. Constantly.”
“Why didn’t Adamov just overrule Petrov? If he is the law here.”
Axelrod flicked Vasin a helpless, pleading glance, as though he hoped to find an ally.
“Can I trust you, Vasin?”
Only a desperate man would ask such a question of his interrogator. Yet Vasin had heard it often enough. There comes a point when every man needs a confidant, even if his words will damn him.
“You can trust me, Axelrod. I promise.” Vasin even truly meant it.
“Petrov has powerful supporters. Had. His father, for instance. Petrov was the only scientist in Arzamas who could really stand up to contradict Adamov. And now he is dead. Adamov can do as he pleases.”
“Which implies, Adamov eliminated him in order to put his sabotage plan into action? Is that what you are telling me, Axelrod?”
“You answer your own questions so succinctly, Comrade.”
Vasin’s own words to Adamov on their first day, flung back at him. But there was no longer any hint of humor in Axelrod’s pale, agitated face.
* * *
—
The street was slick with mushy snow, churned into the consistency of porridge by pedestrians’ feet. Vasin passed a team of street cleaners in padded coats who were scraping the sidewalk clean with broad steel spades. On the corner a snow-clearing machine, the kind they called a capitalist because of its rotating, grasping arms that scooped the snow onto a conveyor, idled waiting for the team to finish throwing the slush into the road. A comforting ritual of Soviet urban life.
Our death-breeding city, Maria had called it. Vasin began to see the menace. The hurrying schoolchildren, the laden shoppers, the comforting clack of closing tram doors, all formed a familiar screen of normality. But sitting on that tram, driving in that car, eating in that restaurant, were men and women who held the death of the world in their minds and hands. Everyone around him had his or her little piece of Armageddon to build. And somewhere beneath his feet, as he walked the corridors of the Institute, the bomb itself was growing in its cellar-womb like a monstrous baby.
Could Adamov have murdered Petrov because he wanted to be free to sabotage the bomb? The project that would crown Adamov’s career with a mushroom cloud of such proportions that the world would stand awed? Why would Adamov wish to reverse a decade’s progress, the research of thousands of his students and colleagues? Sabotage?
Or fear?
Fear of the “unpredictable effects” of a device that was too powerful?
Vasin thought of Professor Adamov’s pale, papery skin, the thin gray bristle that covered his scalp. What was inside that brilliant brain? To hold death, so much death, in that mind of his. And still be calm. How could one carry such knowledge and remain sane?
Vasin could find no obvious impossibility in Axelrod’s story. The timing of the radical new design was certainly suspicious. But why would Axelrod seek him out? Why would a member of the Citadel, that ivory tower so tightly closed to the prying eyes of the kontora, choose a stranger from Moscow to confide in? Unless Axelrod was trying to deflect suspicion from himself?
Could it be, Vasin thought, that it was Axelrod who had slipped a hook into his mouth rather than the other way around?
V
Vasin found Efremov in his office at the kontora, sitting bolt upright at his orderly desk reading a report. Seeing Vasin�
��s head poking around the door, he set the papers facedown and folded his hands into a steeple.
“Not disturbing you, Efremov?”
“Come in, Major.”
Vasin closed the door behind him. Efremov did not invite him to sit.
“I need a favor from you. An important favor. And I promise it won’t involve distracting the golden minds of Arzamas.”
“You seem to have taken a lesson from the General this morning. I understand he set out some checks to your ambition and carelessness.”
“I took careful note.”
“And what is this harmless favor?”
“I need a copy of the lab report, specifically the thallium records.”
Efremov’s face twitched involuntarily. He unfolded his hands and leaned back in his chair.
“May I ask why?”
“Because I have reason to believe they are inaccurate.”
The adjutant’s voice became icy.
“I assume your informant in the Institute, Dr. Vladimir Axelrod, has been making suppositions?”
“It’s irrelevant who I talked to.”
“Oh, but it is relevant, my dear Vasin. Dr. Axelrod is a known troublemaker. A man of dangerous views, an irregular personal life, and unreliable politics. And based solely on the word of this man, you wish to undo the work of an entire State Security team who combed through the laboratory records for days, cross-checking under supervision. To what end this folly? Are you driven to turn the Petrov tragedy into a detective mystery? Or did Orlov send you to deliberately disrupt the most important show of Soviet might in history?”
“Is that a no?”
Efremov struggled to keep his composure.
“It is a no, Vasin.”
Unbidden, Vasin squared a chair directly in front of Efremov and sat.
“You are covering for somebody. I don’t know why, or for whom, but you’re hiding something.”
Efremov smiled thinly.
“Wild accusations are all you have left. You seem to have me confused with some hapless patsy you have pulled off the streets of Moscow.”
Black Sun Page 14
