Sich Discovers Chernobyl Worse than Prior ReportsBy Ramy A. Arnaout
Associate News Editor
Alexander R. Sich, a graduate student in nuclear engineering, reported that the Chernobyl nuclear meltdown was much worse than Soviets had previously admitted. His doctoral thesis provided a definitive study of the disastrous meltdown near Kiev, Ukraine, that occurred nearly eight years ago.
Sich spent 18 months researching near the site of the April 26, 1986 explosion, speaking with experts, examining official reports, and exploring the crumbling concrete sarcophagus that encases the remains of the reactor.
Contrary to existing reports, Sich concluded that the helicopter airlifts of 5,000 tons of clay and other materials to smother the smoldering reactor core was unsuccessful.
The pilots of the over 1,800 helicopter missions were told to aim for a "red glow" in the reactor building, which Soviet officials believed to be the burning core. According to Sich, the pilots hit the wrong target. His research indicated that the core was actually located about 50 feet from the glow. The source of the glow remains uncertain. However, it could have been a small chunk of burning reactor material ejected during the initial explosion, according to The Boston Globe story on Jan. 30.
Because the core was never smothered, the reactor continued to burn for 10 days before finally extinguishing itself, according to Sich. The core underwent what experts consider the worst-case scenario -- a complete core meltdown, he said.
Nine days after the accident, the liquified core melted through the 6-foot radiation shield of the reactor chamber and spilled out onto the concrete floors of the level beneath, Sich believes. There the material spread out enough to end the nuclear reaction, according to the Globe.
Sich believes that the reactor emitted between 185 and 250 million curies of radiation because the core was not shielded immediately. These levels are three to five times as high as the 50 million curies reported in the official Russian account. One curie is the amount of radiation given off by one gram of radium.
In addition, Science reported that the large amount of radiation seems to be linked to a higher incidence of thyroid cancer among children in Ukraine and nearby Belarus.
Connections aid work
Sich had no official permission to perform his research, according to the Globe. However, he gained access to official records and to the site with the help of Alexander Borovoi, the Russian scientist in charge of monitoring and studying the Chernobyl disaster. Sich, a Ukrainian by descent, was also aided by his ability to speak both Russian and Ukrainian.
Sich's findings confirm the suspicions of many scientists who have visited the disaster site. Although they suspected that more radiation was released than Soviet reports recognized, Sich "has given enough new data to show that it is plausible," said Professor of Nuclear Engineering Norman C. Rasmussen, Sich's thesis adviser, according to the Globe. "I think the evidence is very strong."
Part of what made such thorough research possible was the amount of time Sich spent investigating the accident. Richard Wilson, professor of nuclear physics at Harvard University, said in the Globe, "Being there one day at a time is no comparison to being there 18 months [as Sich was] and really getting a clear sense of things."
Sich's research provides "probably the best analysis of what took place during the 10 days after the accident, of what [the Soviets] did, and what they tried to do," Rasmussen said.
With this research, Sich submitted an exhaustive 500-page doctoral dissertation, which was accepted by the department of nuclear engineering earlier this month.
"It is indeed disturbing that almost eight years after the accident, the first and only nuclear engineer from the West permitted to conduct research at Chernobyl was an American graduate student," Sich said. "The most important thing for me was living with [the Ukrainians and Russians] and seeing them day to day."
Core threatens environment
At present, the Chernobyl complex remains far from safe. The reactor continues to emit dangerous levels of radiation. Weakening structural confines are also threatening to contaminate the region's water supply, according to the Globe.
Over 11,000 square feet of holes in the reactor's sarcophagus structure are allowing rain and air to come into contact with the radioactive core, according to the Globe.
In addition, a dam originally built to protect the nearby Pripyat River may in fact be leading up to another disaster. The dam causes the water table, or the underground water level, to rise. If the table rises high enough, it may wash over low-lying radioactive waste in the reactor complex, where "one hundred eighty tons of partially burned nuclear fuel remain," according to Borovoi.
Ukraine, burdened by internal political turmoil and a debilitated economy, will have little revenue to correct these problems in the near future. For example, Ukraine does not even have enough money to pay for nuclear fuel shipments from Russia, according to the Globe. Nur Nigmatulin, deputy chairman of the government agency that runs Ukraine's nuclear power facilities, said that Russia recently announced it would be suspending nuclear fuel shipments to Ukraine unless past fuel debts are payed.