Dark Sun: The Making Of The Hydrogen Bomb

The modus vivendi that the United States had negotiated with Britain and Canada the previous year was due to expire at the end of 1949- Since the US still needed British cooperation to assure itself a supply of uranium ore, Truman called a meeting at Blair House in mid-July to massage the senators and congressmen whose support he would need to broaden Anglo-American atomic relations. Into a small room hung with a huge painting of Franklin Roosevelt crowded Truman (“looking like a tired owl,” Lilienthal thought), Acheson, Louis Johnson (the new Secretary of Defense, large and bald), Eisenhower (who had just given up thirty-five years of chain smoking and was still twitching), and a phalanx of legislators including Arthur Van-denberg, McMahon, Hickenlooper and young Henry “Scoop” Jackson. Most of the discussion rehashed the earlier arguments that had resulted in the modus vivendi. But Truman revealed a significant change in his attitude toward atomic policy that evening. “I am of the opinion we'll never obtain international control [of atomic energy],” he told the leaders. “Since we can't obtain international control we must be strongest in atomic weapons.” Truman appointed a Special Committee of the National Security Council on July 26, 1949, consisting of the Secretary of State, the Secretary of Defense and the chairman of the AEC to study and evaluate the new JCS atomic weapon requirements. All three had attended the Blair House meeting, however, and heard Truman's opinion, which thus effectively foreordained the outcome: the United States would respond to the failure of international diplomacy by building more atomic bombs.

No one had briefed the press on the purpose of the Blair House meeting. Reporters filled the vacuum with a fantastic story: that the meeting had been called to consider “the detonation of three atomic bombs in Russia.” Apropos this revelation, Henry Jackson told one of Borden's aides in late July that he did not take “any stock in the possibility of the Russians actually exploding the bomb.” Jackson had good reason not to do so. On July 1, 1949, the CIA had issued its top secret annual report on the status of the Soviet atomic energy project. The intelligence agency repeated its previous estimates — that the Soviet Union “might be expected to produce an atomic bomb [by] mid-1950 [with a] most probable date [of] mid-1953” — but noted new evidence of Soviet work on gaseous diffusion which suggested “that their first atomic bomb cannot be completed before mid-1951” With a test of that first atomic bomb only weeks away, Lavrenti Beria would have been amused to know how badly the CIA was misinformed.

19 First Lightning

Billowing coal smoke, a train left Sarov in the late summer of 1949 carrying soldiers, scientists and the carefully husbanded components of the first Soviet atomic bomb. The first American bomb, of which RDS-1 was a precise copy, had gone under canvas by open truck from Los Alamos to the desert of southern New Mexico in the summer of 1945, but Russia required rails and trains — an old, rugged technology of iron and steam — to quarter its immensity; from Sarov to Kazakhstan the bomb train drove down cleared and guarded tracks two thousand miles. “We traveled quickly,” Veniamin Zukerman remembers, “stopping only at major train junctions to change engines and to check the rolling stock. We were struck by how completely deserted the platforms were.” Yakov Zeldovich and some of his young assistants jumped out at one stop for a stretch and a game of pickup volleyball; a grumbling MVD colonel chased them back aboard. “But then we were at our destination,” Zukerman concludes. “The engine slowly drew the rolling stock into the zone between two barbed-wire barricades. We drove off… for an inspection of our country's first atomic proving ground.”

The town of Semipalatinsk was sited on high, short-grass steppe land on the Irtysh River in northeastern Kazakhstan. Fifty miles northwest along the river, Mikhail Pervukhin had caused a small settlement to be built, designated Semipalatinsk-21, with laboratories nearby. A road led from the settlement thirty miles south to the test site, in a valley between two small hills. “Along the way there were neither houses nor trees,” writes an eyewitness. “Around was the stony, sandy steppe, covered in feather-grass and wormwood. Even birds here were fairly rare. A small flock of black starlings and sometimes a hawk in the sky. Already in the morning the intense heat could be felt. In the middle of the day and later there lay over the roads a haze, and mirages of mysterious mountains and lakes.” The American test had been code-named Trinity; the Soviets called their test First Lightning.

As Oppenheimer's men had done on the Jornada del Muerto, the Soviets built a hundred-foot tower on which to explode their bomb, but beside the tower they constructed a hall of reinforced concrete with rails and a traveling crane where the device could be assembled indoors. “A freight elevator could lift the car carrying the bomb to the height of the tower,” Zukerman notes. “Personnel could also climb up to the test platform by external staircases.” At Trinity site the desert had been ornamented only with instruments, but the Soviets wanted to study the potential destruction. Besides instruments in the barrens among the mirages, writes historian David Holloway, “one-story wooden buildings and four-story brick houses were constructed near the tower, as well as bridges, tunnels, water towers and other structures. Railway locomotives and carriages, tanks, and artillery pieces were distributed about the surrounding area… Animals were placed in open pens and in covered houses near the tower, so that the effects of initial nuclear radiation could be observed.” Trucks brought the bomb components down from Semipalatinsk-21 in the middle of August.

In the next weeks, Kurchatov conducted two rehearsals. Then Lavrenti Beria arrived with Avrami Zavenyagin, leading a state commission to observe the test. Beria brought with him the two men whom he had sent to witness the US Bikini tests in 1946, the only Soviets who had ever seen the explosion of an atomic bomb. They would report whether the spectacle Beria's scientists were preparing for him was authentic.

Assembly began in the hall beside the tower on August 28 with Beria, Kurchatov, Zavenyagin, Arzamas-16 director Pavel Zernov, Georgi Flerov and Yuli Khariton observing. The assembly crew put together the lower half of the lensed high-explosive shell first — a five-foot brown belly of waxen explosive blocks like a broken geode set into an aluminum case mounted on a wheeled trolley. Into that dark manger of high explosives went the aluminum pusher shell, the heavy purple-black uranium tamper, then the first of the two shining nickel-plated plutonium core hemispheres. Khariton personally checked the nickel-plated initiator for neutron activity before he clicked it into place in the cavity at the center of the core. The second plutonium hemisphere closed the core assembly. Over that, lowered with the traveling crane, went the other half of the uranium tamper and the aluminum pusher shell. It was night before the upper layers of solid and lensed HE blocks had been fitted into place. At two a.m. on the morning of August 29,1949, the workers finally wheeled the bomb on its trolley out the doors to the dimly lit freight elevator below the tower black in the overcast darkness. The bomb was scheduled to ride alone to the top of the tower. Beria expressed surprise and Zernov quickly stepped onto the freight elevator — “holding onto a crosspiece,” says Golovin, “… moving up in an imposing posture.” Four men followed, including Flerov; two of them inserted the sixty-four detonators one by one through openings in the aluminum case into the outer HE blocks and connected them with cables to the big capacitor bank that would fire them. Flerov and a colleague checked the counters that would monitor the neutron background within the bomb. Flerov was the last to descend from the tower. By then, Beria had gone off to a cabin near the command bunker, five miles from ground zero, for a few hours sleep.

“It drizzled all night,” Zukerman reports. As at Trinity, weather forced an anxious postponement; the shot had been scheduled for six a.m. but was moved forward to seven. They had luck with the weather. “Towards morning,” Zukerman continues, “there was a slight clearing. Although the sky was still overcast, there would be no visibility problems.” Kurchatov, Khariton, Pervukhin, Flerov, Zavenyagin and other scientists and managers gathered at the command bunker. Beria and his entourage arrived shortly after the automatic countdown began at T minus thirty minutes and the bunker filled up with generals. Before Beria came out to Kazakhstan, Kurchatov had ordered the earthen berm between the command bunker and the shot tower banked higher, which had blocked the view of the tower; now he opened the glass-paneled bunker door on the opposite side so that they would be able to see the light from the bomb reflected from the distant hills. The shock wave, slower than the light, would hit the bunker after a thirty-second delay, time to close the door again. As he always did, Kurchatov droned as he paced: “Well, well, well. Well, well, well.” At T minus ten minutes, Beria spat a last curse into the mutter. “Nothing will come of it, Igor,” he sneered. Kurchatov reddened at the slur. “I don't think so,” he countered. “We'll certainly get it.”

An eyewitness at an observation post seven miles to the north had no berm blocking his line of sight. “In front of us,” he reports, “through the gaps in the low-lying clouds could be seen the toy tower and assembly shop, lit up by the sun. In spite of the multilayered cloud and wind, there was no dust… Waves of fluttering feather-grass