MOSCOW - A Russian researcher has revealed that the Soviet Union dumped nuclear generators that contained 230 times the reported radioactivity into the Sea of Japan during the 1970s.
According to Y.V. Sivintsev, a 73-year-old researcher at the Kurchatov nuclear institute, a total of four disused nuclear generators removed from submarines were dumped from ships into the sea south of Vladivostok from 1971 through 1979.
However, the Russian government said in a 1993 white paper on the marine dumping of nuclear wastes that it had dumped only two nuclear generators in 1979.
Sivintsev made the finding when he examined top-secret documents that were declassified in 1994. The documents revealed that the Soviet navy had dumped two nuclear generators in 1971 to a depth of 2,000 meters at the bottom of the Sea of Japan.
Sivintsev, who was a member of the team that compiled the 1993 white
paper, said that the Russians accidentally missed
the 1971
dumping because they were rushing to finish the report.
Sivintsev also recalculated the amount of radioactivity contained in the four generators and concluded that the figure was actually some 10,700 Curies -- 230 times higher than the originally reported amount of 46.2 Curies.
The four generators, however, contained no spent nuclear fuel and posed little threat to the environment, said Sivintsev. A 1994 joint study by Japan, Russia and South Korea also reached a similar conclusion.
More serious in terms of potential environmental damage was an accident that occurred in August 1987, according to Sivintsev.
In the incident, a helicopter lost its balance and ended up dumping six spent nuclear generators off the eastern coast of Sakhalin. The generators contained strontium 90 with radiation the equivalent of 683,000 Curies.
Soviet authorities inspected the site of the disaster but were unable to find anything. The radioactive effects on the nearby ecosystem remain unknown, according to Sivintsev.
Sivintsev reported the incident to an international conference on ocean pollution in Monaco in October 1998, but he received no inquiries from the Japanese government.
The Japanese people were surprised by the disclosure in 1993 that
the Soviet Union had dumped nuclear waste into the Sea of Japan, but
the threat of nuclear pollution caused by dumping used, highly
radioactive generators is far greater,
said Sivintsev in reference
to the 1987 incident. An independent, international inspection into
the case should have been carried out.
According to Kenkichi Hirose, a Science and Technology Agency official
in charge of nuclear safety, the Japanese government inspected the
nuclear dumping sites when the Russian government formally presented a
report in 1993, and concluded that there was no danger
to the
Japanese people. He did not comment on Sivintsev's revelations.