By Renfrey Clarke
MOSCOW — The 1986 accident at Chernobyl was not the first case in which the Soviet nuclear industry contrived to pour huge quantities of deadly radionuclides into the environment. In terms of total radioactivity released, the Chernobyl plant scarcely rates a mention beside another Soviet-built nuclear complex — the worst radioactive polluter in history.
The holder of this grim world record is the Mayak Chemical Combine, situated in the southern Urals north-west of the industrial city of Chelyabinsk. Between 1948 and 1990, Mayak produced plutonium for the Soviet nuclear weapons program. Throughout much of this period, it routinely poured nuclear waste into the rivers, lakes and atmosphere of the region. A total of 18 recorded accidents between 1954 and 1990 included the world's second-worst explosive release of radioactivity, in 1957.
Today, the area immediately downwind of the Mayak plant remains one of the most heavily irradiated territories on earth. And although the plant no longer produces plutonium, the risk of further contamination has again become critical. At a government commission meeting attended by journalists on May 5, a Mayak official made a plea for funds to stop contaminated water overflowing from storage ponds and pouring into the nearby River Techa.
The first nuclear reactor at the top-secret combine began operating in June 1948, creating the plutonium that in August 1949 was exploded in the USSR's first test of a nuclear bomb. Eventually, five graphite-moderated plutonium-producing reactors were built at Mayak, as well as several heavy-water reactors. The combine became one of three key centres producing fissile materials and conducting research for the nuclear weapons program. To house the workers and scientists, the secret city of Chelyabinsk-65 was built nearby.
Release into rivers
As early as July 1947, a decision was taken to release liquid radioactive waste from the plutonium extraction plant at Mayak into the River Techa, whose waters flow eventually into the Ob river system and the Arctic Ocean. Tens of thousands of people living along the Techa and Iset rivers were told nothing of this decision until the rivers and their flood-plains had become heavily contaminated.
In November 1951 large-scale discharges into the Techa were halted, after an estimated 2.75 million curies of radioactivity had been poured into the river. In December, the Soviet authorities began evacuating 8000 people from 20 local settlements.
From this time, low and medium-level liquid wastes were poured into a system of ponds centred on the small Lake Karachay. Eventually, the lake became the dumping site for some 120 million curies of radioactivity, out of a total of more than a billion curies that the Mayak combine is estimated to have released into the environment. For purposes of comparison, the amount of radioactivity released in the Chernobyl disaster was about 140 million curies.
Explosion
In September 1957 came the accident for which Mayak today is most notorious. Equipment supposed to cool a large tank of liquid waste broke down, and the waste overheated. Hydrolysis led to an accumulation of hydrogen, and a chemical explosion then blasted an estimated 20 million curies of radioactivity into the air.
Of this quantity, an estimated 18 million curies remained on the territory of the Mayak plant. The remaining materials rose to a height of as much as 1000 metres, and spread to the north-east for at least 350 kilometres in a plume some 30-50 kilometres wide, stopping just short of the large city of Tyumen. An area of about 23,000 square kilometres was contaminated to a degree of at least 0.1 cu/sq km.
An exclusion zone was later created, encompassing about 700 square kilometres of the most heavily contaminated territory, and some 10,730 people were evacuated from 23 settlements.
The accident remained shrouded in secrecy until some of its features were described for western readers in a 1976 work by exiled dissident biologist Zhores Medvedev. Analysing publications by Soviet scientists on the effects of irradiation of the natural environment, Medvedev deduced correctly that a major nuclear disaster had occurred during the 1950s in the southern Urals.
A further large-scale dispersal of radiation took place in the spring of 1967. This time dry, windy weather lowered the water level in Lake Karachay; the wind then lifted radioactive dust and spread it over an estimated 2700 sq km. The total radioactivity involved was about 600,000 curies.
As well, radioactivity continued to spread from the plant and from waste storage facilities on a continuous basis. Throughout Mayak's history as a plutonium production complex, radioactive materials were released into the atmosphere through 150-metre chimneys.
Most of these materials were relatively short-lived gaseous isotopes. But recent data indicate that aerosols of heavy radioactive elements were also present. In this way, an area of more than 10,000 sq km around Mayak became contaminated with plutonium.
Meanwhile, liquid wastes continued to pour into lakes and ponds that lacked impervious clay bottoms. Beneath these reservoirs, a lake of contaminated ground water was spreading and threatening eventually to flow into local streams.
Health effects
Determining in detail how the health of Mayak employees and local residents has suffered is difficult. However, there is reason to believe the damage to health has been considerable. In the early 1950s, particular meadows near villages along the River Techa were delivering a lifetime "safe" dose of radioactivity in a few hours. The people of these villages were using the river as a source of drinking water, and ingesting large quantities of highly dangerous strontium-90.
Among Mayak workers, a total of 1380 cases of chronic radiation sickness were diagnosed between 1949 and 1968. Of these victims, 117 died between 1952 and 1989.
To some degree, the effects on health have been masked by a steep rise in cancer rates among the population on Chelyabinsk province as a whole. Studies show that the correlation here is with the presence of metallurgical and chemical plants, rather than with spills of radioactivity.
In theory, the acute phase of the danger from Mayak ended in 1990, when plutonium production ceased. Since then, Lake Karachay has largely been filled in and covered with concrete. In June 1991, a furnace went into operation for evaporating high-level liquid waste and turning it into a glass-like substance for burial. The US is now paying half the US$300 million cost of constructing a new storage area.
Nevertheless, the dangers have by no means vanished. As the only nuclear waste reprocessing plant now operating in the former Soviet bloc, Mayak is still extracting plutonium and storing it. The amount stockpiled now amounts to some 27 tonnes. At various points in this process, the possibility of accidents remains menacing.
No funds
The problem of storing low and medium-level liquid wastes, meanwhile, remains substantially unsolved — and threatens a new disaster. The holding ponds now contain some 400,000 cubic metres of contaminated water. Every year the water level in the last pond rises by about 20 centimetres as a result of precipitation and the inflow of ground water.
According to Mayak deputy director Yevgeny Drozhko on May 5, the plant desperately needs money to build a further containment dam if waste is not to pour once again into the River Techa. But government funds, unlike the contaminated water, have dried up.
The main "solution" to these problems that has been urged by nuclear industry officials would merely substitute new dangers. Last year these officials were pushing hard to revive plans to build a full-scale nuclear power plant about 10 kilometres from Mayak, with three fast-neutron reactors that would use the stored plutonium as fuel. Waste heat from this plant would be used to raise the temperature of the contaminated water in the ponds, increasing evaporation rates and lessening the danger of an overflow. This scheme was again urged by deputy emergency situations minister Viktor Vladimirov on May 5.
In the Soviet Union, the nuclear industry was protected by secrecy from public scrutiny, and pressured to compromise on safety by officials eager for output at any cost. But when safety needs were identified, the funds needed to deal with them were usually signed over.
In post-Soviet Russia, the position has been reversed. The devastation wrought by the country's nuclear nomenklatura is now public knowledge. But although the perils remain, and at Mayak are reaching a new peak, the money needed to deal with looming disasters is denied by budget cost-cutters.
Reckless irresponsibility in nuclear matters is not something that has been left behind with state plan targets and the search for strategic parity with the west.