Death of a Dissident - Alex Goldfarb [157]
In a story on December 18, 2006, the Russian Web site Gazeta.ru quoted Ekaterina Shugaeva, press secretary of Techsnabexport, the only Russian company officially licensed to transport and export Polonium-210. “Polonium is extremely complex in production and handling,” she said. “This capability exists only at Sarov [a nuclear facility at an old Soviet weapons lab, near the city of Samara]. No one else has the expertise to produce it.” According to Shugaeva, the production cycle starts with the neutron bombardment of bismuth (a metal) at the Ozersk nuclear reactor, near the city of Chelyabinsk. From there, the half-product is transferred to the Sarov facility. There, the polonium is purified from the bulk of bismuth, enriched, and packed. Polonium-210 is produced in a monthly cycle and is dispensed in capsules, which are placed into sealed containers. The containers are then exported to customers in the United States via an air cargo terminal in St. Petersburg. One hundredth-of-a-gram capsule of freshly produced polonium contains five thousand lethal doses.
When Polonium-210 decays—its half-life is 138 days, meaning that half of any given amount decays in the first 138 days, followed by a fourth in the next 138 days, and so on—it turns into lead, a nonradioactive metal. As the amount of polonium decreases, the amount of lead increases. By measuring the proportion of lead in a sample of polonium, an investigator can figure out how old the sample is and establish the precise date it was produced. Moreover, the production process leaves characteristic isotope impurities in every batch. By comparing the lead content and the impurities present in two samples of polonium, an investigator should be able to say whether they came from the same batch, produced in the same laboratory on the same day.
Samples of Russian polonium have presumably been available to British law enforcement from American sources. The Polonium-210 found in Sasha’s body has by now undoubtedly been checked against the Polonium-210 exported to the United States. From the level of lead and the isotope composition, the investigators should have been able to unequivocally establish the batch and production date of the poison—unless, of course, it originated from an illicit reactor, which is not subject to the IAEA safeguards.
By early spring 2007, the British authorities had not yet released any information related to the polonium source. But there is little doubt that physicists in the British nuclear facilities, working with spies in the British secret services, know exactly where and when the exotic nuclear poison that killed Sasha was produced.
Polonium, once it has been identified, is a detective’s dream. Like an invisible dye it marks everything it touches, and it cannot be washed off. Once the right equipment is used, traces of polonium are detectable in a dilution as unimaginably weak as a millionth-of-a-millionth part. If someone, say, turns on a light in a hotel room with a contaminated hand, the light switch will be radioactive for months. From the amount and distribution of radioactivity on an armchair, an investigator can tell whether it was the right or the left hand that left the trace, and whether the hand was contaminated from the outside or the radioactivity came from the tiny droplets of sweat of someone who ingested the poison. In other words, traces left by a perpetrator and a victim are distinguishable from each other.
The Scotland Yard detectives uncovered several polonium trails in and out of London. Again, no official information has been released as this book goes to press. However, enough has been leaked from reliable sources to London newspapers to reconstruct a more or less complete picture, and the investigators essentially confirmed these leaks to Marina.
Within hours of Sasha’s death, HPA radioactivity hunters identified and closed off