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. Last Updated: 07/27/2016

Plutonium Concern in Aftermath Of Blast

Two days after the nuclear explosion and fire near Tomsk, uncertainty remained Thursday about potential danger to the population, with questions being voiced about a possible discharge into the atmosphere of highly toxic plutonium.

Russian authorities initially told Finnish nuclear experts and the environmental group Greenpeace that both uranium and plutonium had been released by the blast Tuesday at the secret Tomsk-7 military complex. But the State Emergency Committee investigating the incident later said there was no plutonium danger.

The Tomsk explosion has been classified a "serious incident'' involving the release of what is described as a harmless amount of radiation. Although a radioactive cloud moved across parts of Siberia on Wednesday, authorities say they have no immediate plans to evacuate the local population.

According to the emergency committee, the radioactive cloud settled Thursday somewhere over an unpopulated area of the Siberian taiga. Marina Ryklina, a committee spokeswoman, said the cloud had been inspected and classified as "nonradioactive". Itar-Tass said snow had helped bring the cloud down and prevent the radiation from spreading.

A spokesman for the Nuclear Energy Ministry, Georgy Kaurov, told Reuters that the explosion had contaminated 90 square kilometers of Siberian forest, a far larger area than reported Wednesday. He too said the radiation level posed no risk to health.

Reports varied, however, on exactly how far the radiation had spread and what the measurements were.

Ryklina said that the town of Georgiyevka, tiny hamlet of 20 inhabitants 22 kilometers from Tomsk-7, had a slightly higher level of radiation than normal but that this posed "no threat to the health of the people living in the area".

But Greenpeace said that the Siberian town of Nadezhdino had also been seriously affected and that radiation measurements were as high as 4, 000 microroentgens per hour in both towns. The microroentgen is an international unit for measuring radiation.

"People need to be evacuated immediately", said Eduard Gisnatullin, a Greenpeace spokesman in Moscow. "People are exposed to 300 times the usual level of radiation. At least children should be moved, if not everyone".

Esko Ruokola, an inspector at the Finnish Center for Radiation and Nuclear Safety, said it was unlikely any plutonium was drifting over Siberia as the chemical "cannot be airborne" for a long time.

"Plutonium is quite dangerous, but according to the latest reports from Gosatomnadzor (the state nuclear inspectorate) there was none", Ruokola said by telephone Thursday. "If it was released and it is inhaled, then lung cancer almost certainly will result".

Greenpeace, however, said it was certain plutonium was released since, according to its information, the explosion occurred in a tank holding reprocessed nuclear fuel, which would contain plutonium.

This is at variance with previous reports that the blast occurred in a waste tank.

U. S. experts quoted by The Washington Post also cast doubt on the waste tank version, saying the explosion more likely occurred in an area where spent nuclear fuel is dissolved in a chemical bath to extract its plutonium content.

It remains unclear why the explosion occurred. The plant's director, Gennady Khandorin, told Izvestia that, for unknown reasons, the pressure in a 34-cubic-meter tank had risen so fast that it destroyed the tank within six minutes. The explosion tore off a reinforced slab covering the tank, short-circuiting the plant's electrical systems and starting a fire.

Khandorin said workers had not been evacuated, although one fireman called to the scene had received a high dose of radiation.

Television reports showed workers in white protective clothing cleaning up contaminated areas and taking measurements with Geiger counters.

The Tomsk-7 facility, one of three Plutonium-processing plants still operating in Russia, was built in the 1940s as part of the Soviet nuclear weapons-building complex. It is now officially used only for the nuclear power industry, although the settlement of 100, 000 is closed to foreigners and does not appear on maps.

Lidiya Popova, a nuclear physicist at the Socio-Ecological Union, a Russian environmentalist organization, complained about the number of conflicting reports.

"Officials don't know the exact situation", said Popova who visited Tomsk-7 twice last year. "I'm very worried. Independent controls are necessary. If the waste contained plutonium and it was dispersed into the atmosphere, then the local population is in serious trouble".

Plutonium is fatal if inhaled in large doses and can cause cancer in a later phase if inhaled in smaller doses.

Popova said she was certain that the accident involved plutonium-239, which she said was used at military complexes like Tomsk-7. She added that plutonium does not penetrate clothing, but that it can enter the body through inhalation or an open wound.

According to Popova, Tomsk-7 has an entire fuel cycle conversion complex on its premises.

She said it has five production reactors, of which only two to three are operational; at least one is used for heating Tomsk.

The accident, which was rated three on the International Atomic Energy Agency's seven-point scale, has stirred anxiety in the country and comparisons to the 1986 Chernobyl disaster were not uncommon in the Russian press.

"The nuclear monster spoke up in Siberia and the entire world felt its danger", read Thursday's headline about the incident in Izvestia.

Yelena Bonner, the wife of the late nuclear physicist Andrei Sakharov, expressed concern about the incident.

"We need Western experts to assess the situation", Bonner said Thursday in a telephone interview. "Our experience with Chernobyl proved to us that we need help when such accidents take place. The fact that this factory was producing secret weapons is the most worrisome. International control needs to be increased".