Yuri Kanin, Nature’s Moscow correspondent reported on Chernobyl (With Dosimeter in the Sarcophagus’, Nature, Vol. 339, 171-172, 1990). He describes the events thta have occurred recently as regards returns and resettlements in the region, continuing programmes of decontamination, rehabilitation, and research. Excerpts follow.
Chernobyl, with almost 800 years of history, had a predisaster population of 18,300. Now, it houses 6,000 people on a scheduled basis: 15 days in the zone and 15 days with their families outside. The buildings are repeatedly decontaminated.
Although radioactive objects have been decontaminated and removed and short-lived isotopes have disappeared, the ‘caesium period’ has now set in. (Long-lived caesium-137 and caesium-134 will be the chief contaminating isotopes for a considerable time.)
The town will, of course, remain. My firm belief is that it must become the centre of an international research site. Many of those to whom I have talked in Moscow, Chernobyl, Pripyat and at the nuclear station are coming round to the idea. There is undoubted interest abroad.
But some people have already returned to live in villages in the 30-km zone, happy to be at their hearths again. About 1,000 people are now living with elevated radioactivity. They are supplied with uncontaminated food and are regarded as brave people defying an invisible threat. But why do not the authorities exercise their authority? Most of them may be old people who have found it difficult to put down roots in new places, and the levels of radioactivity in the villages may be low. But people do not stay at home all the time; they go to the woods to pick mushrooms, they tend grazing cattle and many of them drink locally produced milk. Grandchildren are already paying visits, to take a country holiday and breathe ‘fresh air.’ The zone is no place for permanent living.
(In the town of Pripyat) the famous blue spruce trees are blue only at the top, with the rest of their needles green as in pine trees, but half as long again.
Kompleks (a communal service enterprise at Pripyat) is now creating a protective buffer zone of forest belts around the nuclear plant and Pripyat. It is also trying out a novel decontamination technology … three years ago, when the activity was high and the work dangerous, decontamination meant spraying, the removal of topsoil or both. Now the objective is to use electrochemical, acid, alkali and high-temperature and polymer treatments to process the waste into a compact mass. Then, extending the network of burial grounds can be avoided while the emplacement of compacted waste in fixed storage will be much more reliable.
Next July, Spetsatom (another communal enterprise) plans to test in the Chernobyl Zone an installation for soil-decontamination using infra-sound. It can separate, fraction by fraction, radioactive particles ranging from 20 to 400 mm. One installation can decontaminate 100 tones of soil an hour (or in one year, could treat soil to a depth of 0.2 m over an area of 100 km^2^).
An expert group from the Moscow-based Kurchatov Institute of Atomic Energy has been drilling holes into the bowels of the destroyed reactor. Why should anything of this sort be done?
Igor Kambulov, Head of the Kurchatov Institute group, says that the objective is partly research and partly the enhancement of the safety of the structure. The group plans to tell by drilling the exact location of the fuel mass. ‘We have found that its state is stable and subcritical by a wide margin’, so that a spontaneous chain reaction is highly improbable. But to enhance the degree of subcriticality … the group has been inserting further neutron absorbers … ‘the maximum temperature of the fuel is 150°C and it is falling steadily.’
You understand how difficult it is to control (radiation in the vicinity of the reactor) and realize how indebted we are to the brave men working there … until they receive the maximum permissible dose of radiation. Kambulov told me that the personnel working inside the Sarcophagus had been replaced five times since 1988.
And, lastly –
Changes in the flora and fauna of the zone are of special interest to researchers … a handful of enthusiasts are working on the greenhouse farm of the city of Pripyat, also a very interesting subject; they have many plans and ideas, but for the time being lack the necessary funds and instruments. But I believe they have started something. Chernobyl is a dark episode in the history of mankind which may yet serve as a world laboratory and so help prevent similar accidents.
Vera Rich, writing from Cracow (‘Concern Grows Over Health of “Chernobyl Children”, New Scientist, April 21, 1990), states that
In Palessie, in southern Byelorussia; between 50 and 70 per cent of children now have health problems. About 8 percent have thyroid complications in forms that had not been observed before Chernobyl. The incidence of cancers and congenital deformities was significantly high, the seminar was told. Meanwhile common illnesses had become up to 20 percent more common in the area because people’s immune systems had been weakened by radiation exposure …
… researchers estimate that one-fifth of the children in Byelorassia had received 10 gray or more since the accident — 10 times as much as would be needed to cause illness, and about 100,000 times as much as people normally encounter in a year from background radiation.
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