Chernobyl Accident Studied

Eight years after the explosion at the Chernobyl 4 nuclear reactor in Ukraine, an MIT graduate student has concluded the accident was far worse than previously thought, according to an article in Sunday's Boston Globe.

Alexander Sich '90, who has just completed an 18-month investigation of the Chernobyl site, told the newspaper that, in contrast to official Soviet reports, there was a complete meltdown of the reactor core during the 1986 disaster.

He also found that the amount of radiation released was between four to five times more than previously reported by Soviet officials.

Sich's research was part of his doctoral dissertation for the MIT nuclear engineering department.

Sich, who is fluent in Ukrainian and learned Russian as a Harvard undergraduate, worked closely in Chernobyl with Russian scientist Alexander Borovoi, who is in charge of research at the nuclear facility. Borovoi allowed him to gain access to the site and all of its records.

This level of access is unprecedented for a Western scientist, and even more unusual considering that Sich is a graduate student, the Globe said.

During his extended stay in Ukraine, Sich toured the premises, talked with workers and scientists and sifted through documents detailing what happened in the days before and after the devastating 1986 accident.

On April 27, the day after the accident, orders were given to six helicopter pilots to begin dumping materials on the reactor to put out the blaze.

The pilots were told to aim for a "red glow," which was believed to be emanating from the core.

Sich, however, said this measure was totally ineffective because the pilots actually missed the reactor core by about 50 feet.

He said he thinks that the "red glow" may have been a chunk of the reactor that was hurled away from the core during the explosion.

Unchecked, the core material escaped into the air over the next 10 days, releasing fatal amounts of radiation.

But some experts have questioned Sich's findings. Morris Rosen, deputy director of the International Atomic Energy Agency, told the Globe that the helicopter pilots were successful in their attempts to douse the blaze.

"Material certainly got into the core region," he said. "I can vouch for the fact, since I flew over the reactor days after the explosion."

According to Sich, the radioactive material in the core eventually burned its way through a six-foot radiation shield, melted the floor and quickly spread out over the floors of the lower level of the plant.

After the core spread, it cooled down and "froze" in place. It is still frozen today in the Chernobyl plant.

Following the accident, workers tried to curb the amount of escaping radiation by building a 24-story concrete sarcophagus around the structure.

But Sich said that the concrete encasement is structurally unsafe and in danger of collapsing.

"I believe the sarcophagus was and still is the most dangerous structure in the nuclear industry," Borovoi, the Russian scientist who aided Sich, in an interview with the Globe.

Workers also built a dike to stop radioactive material from leaking into the Pripyat River, located near the Chernobyl site.

Sich said his study shows, however, that the dam is having adverse effects on the surrounding ecosystem. It is holding back ground water and raising the water table, which is now a mere 15 feet below ground.

MIT professor of nuclear engineering Norman Rasmussen, who is Sich's thesis advisor, said that his student's work is very significant.

"[It is] probably the best analysis of what took place during the 10 days after the accident, of what they did, and what they tried to do," he told the Globe.