MOSCOW -- The Soviet Union, consumed by a mania for gigantic development, routinely used nuclear blasts in construction and mining projects from 1965 to 1988, never bothering to calculate the cost to people or environment.
"They never studied the long-term effects," said Boris N. Golubov, a Russian scientist leading an inquiry into the explosions. "And we're only starting to feel them now."
And in its haste to develop its vast resources at all costs, Dr. Golubov said, the Soviet Union set off 116 nuclear explosions for technical purposes. The most modest of them was equivalent to the explosion at Hiroshima. A large number were five to 10 times more powerful, and one was 165 times more powerful.
Dr. Golubov said there was simply no thought given to the effect on people and the environment. Though the blasts were carefully controlled at the time of the explosion, they were quickly forgotten, he said. No one studied their impact.
The explosions were monitored in the rest of the world -- their force could hardly have gone undetected -- but most Soviet scientists knew of them only by rumor until 1990, when the old controls on information began to weaken. The average person had no idea that there was any danger, and there was no debate about the wisdom of this course.
Today, the consequences of that heavy-handed policy are still unfolding, Dr. Golubov said. Together with unsafe Chernobyl-like nuclear power plants and wanton disposal of nuclear waste at sea, Russia has inherited a nearly catastrophic radiation problem.
The nuclear bombs were used across a wide swath of the Soviet empire to build dams, prospect for coal, gas and oil, create underground reservoirs and even to blow apart huge rocks to get at the metals inside.
Though the explosions were underground, their results were often wildly unpredictable. Some heaved tons of contaminated dirt into the air. Others profoundly altered geological structures, such as a project at Astrakhan near the mouth of the Volga River. There, Dr. Golubov fears, radioactive water will eventually flow into the Caspian Sea, home of the caviar industry.
Others undertook to rearrange nature, by reversing the flow of great rivers.
"Of course it was a mistake," said Dr. Golubov, a member of the respected Russian Academy of Sciences. "They often didn't get the results they wanted. And they could have gotten results by other means. It was stupid."
In those days of megalomania, before the Soviet empire collapsed on itself, the pursuit of power was paramount, scientists said. Technology was worshiped, and it was considered foolish to drag around tons of TNT when a small, awesomely powerful bomb could do the work more quickly and cheaply.
In Yakutia, a diamond- and oil-rich autonomous republic in Siberia now called the Republic of Sakha, a dozen blasts were set off from 1974 to 1987.
"It was a terrifying time," said Alexander S. Tsygonov, a nuclear radiation inspector in the capital of Yakutsk. "And there was never any discussion of it until 1990."
First try failed
The first explosion in Yakutia, near the huge diamond mine at Udachny, was a failure. The equivalent of 1,800 tons of TNT, set off at a depth of about 300 feet, was meant to create a dam that would produce water needed for diamond processing.
"It was too close to the surface," Mr. Tsygonov said, and the only result was a highly radioactive mound of dirt, which can be seen today from the town.
Udachny, an Arctic town of 22,000 which had only 5,000 people then, is only a mile and a half away. Inhabitants reported seeing a mushroom cloud, but no one was unduly alarmed.
"The population wasn't informed about nuclear explosions," Mr. Tsygonov said. "They trusted the authorities."
Even local officials were uninformed and unconcerned. Lev A. Safonov, vice president of the powerful Almaz Rossii-Sakha, which operates the diamond mine at Udachny, said the blasts in general posed no problems. And the one at Udachny that went wrong did no harm, he said.
"It is all blocked up with rocks for many meters," he said. "It was just an experiment. Usually construction lasts several years and one explosion could do all this work at once. But once it was done and the calculations were not confirmed, they stopped it."
That failed explosion occurred in 1974, and many others followed until the last one in 1987.
The 116 nuclear explosions carried out by the Soviet Union varied in force, ranging from the equivalent of nearly 1,000 tons of TNT to up to 165,000 tons of TNT. Forty-three were in the range of 5,500 to 11,000 tons of TNT.
In 1978, a blast equivalent to 20,900 tons of TNT was set off at Kraton 3, 24 miles from the Yakutia diamond town of Aikhal, which is 100 miles from Udachny. The Ministry of Geology was prospecting, trying to draw a geological profile that would indicate whether the ground held ore or other valuable deposits.
The explosion left far more radiation than was expected, making it impossible to do any sort of mining. Mr. Tsygonov displays a picture of the site, a desert-like field with a dying forest in the background.
Mr. Safonov, whose company operates the diamond mine there as well, conceded that that explosion was more dangerous.
"At Aikhal there were some long-living isotopes found," he said, "but I do not know details."
Dr. Golubov said the explosion went awry, the cement cork plugging the hole blew out and a stream of radioactive gas
spewed into the air.
"They analyzed accidents when they occurred," he said, "but the effects of five, 10 or 15 years later were ignored."
In 1990, Mr. Tsygonov decided to catalog the nuclear explosions in Yakutia and to warn of potential dangers from radiation. But the reaction was typical of the Soviet mentality.
"My report wasn't published by the government, only privately," he said. "And the first reaction from Moscow was to send specialists here to try to find mistakes in it. But it was a serious report, and they couldn't find any mistakes."
While the nuclear explosions were used to tackle the specific problems of permafrost -- quickly blasting through earth frozen harder than rock -- they may have created some special problems of their own.
"We don't know how radiation affects us here in the permafrost," Mr. Tsygonov said. "We live here on a sheet of ice. We don't know if the permafrost intensifies the problem, but we know the radiation stays on the surface and can't enter the permafrost."
There have been no long-term medical studies to document what effect the nuclear blasts had on people, though Valentin I. Arkhipov, vice minister of ecology for Yakutia, said statistics indicate that both health and longevity have been adversely affected in Yakutia.
"We can definitely say the explosions have had an influence," he said, "but we don't know how much and where."
Dr. Golubov said the United States also conducted nuclear explosions for industrial purposes, as confirmed in reports recently declassified by U.S. Energy Secretary Hazel O'Leary.
"The Americans stopped in 1972 for economic and ecological reasons," said the Russian scientist. "Here, public reaction was not possible. But in the United States, public protests began, and scientists warned of the consequences. They understood there were risks. But our program was still going on."
Perhaps the most infamous of the Soviet projects was one Dr. Golubov called one of the most grandiose: to reverse the flow of major rivers in Siberia. Soviet scientists planned to build a 70-mile canal near Perm in Central Russia, to divert the north-flowing Pechora River to the south-flowing Kola River, which flows into the Volga. They wanted to replenish the Caspian Sea.
In 1971, they set off three nuclear explosions equivalent to 45,000 tons of TNT -- 45 times more powerful than the blast that destroyed Hiroshima -- creating a crater 2,300 feet long and 50 feet deep. Another 250 were planned along the proposed path of the canal.
Soviet scientists proudly reported the explosion in 1975 at a meeting of the International Atomic Energy Agency, though they were vague about details, such as the date.
"In the explosion zone the radioactivity for many years was 1,000 times as much as natural background radiation," Dr. Golubov said. "At the time they praised it to each other as a great achievement. But the extent of the pollution cooled some enthusiasm even in the Ministry of Atomic Energy. Finally they realized no good could come of 250 explosions there."
A Russian reporter recently took a Geiger counter to the site, and said the radiation was so high he couldn't measure it.
Russian citizens, who once were so easily reassured, now are suspicious of everything. They recall that everything was set for further explosions on the project in 1976. Now, residents of Perm claim that unexploded nuclear bombs still lie beneath the earth, ready to go off.
"Nobody knows if the bombs were ever removed," said Nikolai Khudyakov, a forest ranger. He said townspeople believe the bombs were simply forgotten.
Nuclear officials deny this, and scientists tend to believe them, .. thinking it would be inconceivable for even the old authorities to leave nuclear bombs lying about.
But a people jaded by Chernobyl and a deeply damaged environment are not so sure.
Officials at the Russian Ministry for Environmental Protection concede that mistakes were made -- some serious indeed. But they say Russians should not be unduly alarmed.
"You can't change history," said Andrei Pechurov, a specialist on the effects of radiation. "What was done was done. It's an experiment valuable not only for Russia but for mankind."
Dr. Golubov fears that his nation will pay a higher price than anyone cared to imagine for these grand schemes.
"We'll be forced to spend 100 times more than they got from oil projects to research and reverse what they did," he said.
Dr. Golubov, who is leading a commission studying the effects of the industrial explosions, said his group began studying oil and gas projects first, because of fears that underground water might be affected. From 1980 to 1984, he said, 15 underground explosions were set off at Astrakhan to create underground gas reservoirs.
Dust in atmosphere
"Almost all of these explosions released radioactive dust into the atmosphere, but this was never mentioned," he said.
The explosions created temperatures hot as the sun, which caused stones to melt and form a sort of glass ceiling over the reservoirs. The reservoirs, cave-like structures, were supposed to hold gas for 30 years, supplying it to a plant on the ground.
"In 1986, all 15 caves collapsed nearly at once," Dr. Golubov said. "Some of them took in water. And highly radioactive water began to pour out of them, very near the Volga and Caspian Sea."
As a result, the supply of gas was interrupted, further exploration of deposits appears impossible and the reservoirs became depots for uncontrolled nuclear wastes, Dr. Golubov said.
Even more alarming, he said, the ground water began to rise, threatening to flow into prehistoric river beds that now lie under the surface of the earth.
"We worry that those prehistoric rivers will connect to radioactive water," he said. "Regional pollution could start that could penetrate the Volga and Caspian."
Such contamination could threaten fish and people.
"It could be a huge ecological disaster, a catastrophe," Dr. Golubov said. "What is very important is that this disaster is still developing, and we cannot predict all the consequences. We just don't know what might happen."