Russia is considered one of the most radioactively contaminated countries in the world. Basically contamination is the legacy of the Cold War. It was caused by:

• Nuclear weapons testing at Novaya Zemlya and at Semipalatinsk test site (Kazakhstan);

• plutonium production in the South Urals, Krasnoyarsk and Tomsk regions;

• dumping activities and naval nuclear reactors.

Military and “peaceful” programs were developed almost in parallel. They are managed by the same agency. Uranium mining was developed for both programs. Except of this, contamination from “peaceful” nuclear activities was caused by:

• facilities of the nuclear fuel cycle (nuclear power): uranium enrichment plants, fuel fabrication plants, reactors of nuclear power plants, reprocessing plant;

• peaceful nuclear explosions;

• satellite failures.

In this paper we shall focus on radioactive contamination from the facilities of the nuclear fuel cycle. We shall start from the back-end of the fuel cycle. As reprocessing technology for the spent fuel of the reactors of nuclear power plants in its main features is almost the same as for the spent fuel of the production (military) reactors, it is worthwhile to talk about contamination from the reprocessing plants, whether they are military or commercial.

This is the first plutonium production facility in the former Soviet Union, built in late 1940s in the South Urals, 70 km to the North from the regional city Chelyabinsk. It started operation in 1948 and had 5 uranium-graphite production reactors, all now shut down. It also had a reprocessing plant for separation of plutonium for nuclear warheads, and a number of other plants. In 1977 a reprocessing plant for separation of plutonium from the spent fuel of WWER-440, BN-350, BN-600, submarine and research reactors, was build on “Mayak” site.

Mayak.

Operation of the “Mayak” was marked by three major radioactive catastrophes, which led to contamination of the vast territories.

1. During 1949-1956 liquid radioactive waste (including high level) from production reactors cooling system, reprocessing and chemical-metallurgical plants was disposed directly into the river Techa system. The total discharge of radioactive waste, containing cesium, strontium and plutonium, was 76 million m³ with the total activity 2.8 Million Curies (in β-radioactivity). The river Techa was contaminated along its flow (240 km), and river Iset, for which Techa is a tributary, was also partly contaminated. 124 thousand people, mostly residents of the villages located on the banks of the river Techa, were subject to radiation. Many of them developed acute and chronicle radiation disease. 7,500 people were relocated from the villages, where effective dose for population comprised from 560 mZv to 1400 mZv (56-140 rem), by the year 1960. Residents of the village Muslyumovo continue to live in contaminated area. The wire fence that separated the village from the river, is broken, and there is no limitation for the access to the river even for children.

2. In September 1957 a tank containing high-level waste from the reprocessing plant exploded due to the failure of the cooling system and self heating of the explosive salts on the bottom of the tank. This explosion is known as Kyshtym accident. 20 million Curies were spewed out into the atmosphere. 90% of radioactivity failed on the “Mayak” site. The rest of radioactivity (2 Million Curies) was dispersed over Chelyabinsk, Sverdlovsk and Tumen regions and formed the so called East-Urals Radioactive Trace (known as VURS). The area contaminated by ⁹⁰Sr at the level 0.1 Ci/km², comprised 23,000 km². This territory hosted 217 villages and towns with the total population equal to 272,000 people. During 2 years 10,200 people were relocated.

3. After 1951 discharges of high and medium level waste into the Techa river was stopped, and this waste was discharged into the small (about 0,45 km²) swamped lake Karachay. Eventually Karachay was transformed into the storage facility for liquid radioactive waste and accumulated about 120 Million Curies of cesium and strontium. In may 1967 during extreme drought, strong gusty winds (small tornadoes) distributed radioactive dust from the stripped lake-side over an area about 1800 km². This contamination basically overlapped the plume from the Kyshtym accident. The total contaminated area was 2,700 km². In 63 villages and towns population comprised 41,500.

4. The reprocessing plant RT-1 also contributes to the radioactive contamination of the South Urals. Investigation conducted by one private company in 1990s, demonstrated that in the period 1988-1990 concentration of isotopes ²³⁸Pu+²³⁹Pu+²⁴⁰Pu in 10 cm layer of soil increased 5 times. Isotopic composition of plutonium in soil before 1976, i.e. before the start of RT-1 operation correlated with the isotopic composition of weapons plutonium. After the start of RT-1 operation, the input of ²³⁸Pu increased, that witnessed about the impact of RT-1 on the environment. The scientists came to the conclusion that due to the atmospheric transference of plutonium aerosols, contamination from the reprocessing plant RT-1 far exceeds the observation zone. Contamination of soil at the distance of 40 km from the reprocessing plant is 2000 Bk/m², and near Chelyabinsk (about 100 km away) it is 500-800 Bk/m². Just to remind, contamination of soil by plutonium as the result of the global fall-out is 100-200 Bk/m².

. This plutonium production facility was built in early 1950s and started operation in 1953. Currently it is the largest in Russia nuclear complex for plutonium production and uranium enrichment. Out of 5 production reactors continue operation 2. They still produce weapons plutonium, at the same time supplying heat for the regional city Tomsk with population 500,000. Although Siberian Chemical Combine escaped such disastrous accidents that happened at “Mayak”, it contaminated the environment by the man made radionucleides. Discharge of radioactive coolant from the through way production reactor into the tributaries of the river Ob’ was stopped only in December 1990. The most serious is contamination of the floodlands of the local rivers by the long lived isotope ²³⁹Pu. In some places contamination is as high as 3100 Bk/m2. The total number of accidental situations and minor incidents at this facility during the whole period of its operation is close to 40. The most serious accident happened on the 6^th of April, 1993, at the reprocessing plant. Explosion in one of the canyons resulted in contamination of the site by plutonium and in the dispersion of β-active radionucleides along 25 km to the North-East from the place of explosion. The accident contaminated an area of about 123 km² inside and outside the plant. It was fortunate that the prevailing wind blew the plume into largely forested, unpopulated areas in the North-East, rather than to the cities to the South (Tomsk) and West (Tomsk-7). Two small inhabited villages were contaminated. Later the doctors reported about the health effects in children of these villages after the accident – fatigue, nose bleeding and others.

Siberian Chemical Combine

Siberian Chemical Combine has been practicing injection of the liquid radioactive waste into the underground horizons at the depth of 300 m. The total amount of injected waste exceeded 40 million m³, with the radioactivity more than 1.1 billion Curies. Also, there are 50 storages of liquid and solid radioactive wastes on the territory of the combine. The activity of these wastes amounts to 125 million Curies. Some liquid waste is stored in open reservoirs.

This is the third large facility for production of weapons plutonium. For this 3 production reactors, out of which one is still in operation, and a reprocessing plant have been built. Krasnoyarsk Mining Chemical Combine was built in the mountain. To build it the amount of rock equal to the space of the Moscow metro, has been excavated. Likewise it was practiced at the Siberian Chemical Combine, the radioactive coolant from the through way production reactor was discharged directly into the river Enisey. The Enisey floodlands are contaminated by the man made radionucleides, including ²³⁹Pu, along the whole flow of the river up its mouth in the Kara Sea. This facility has been also injecting liquid radioactive waste from the reprocessing plant into the underground layers of sand at the depth of 300-400 m. In late 1970s the construction of the commercial reprocessing plant RT-2 was started on the site of the combine, for reprocessing the spent fuel from WWER-1000 reactors. The construction was halted in 1980s during perestroika, and only storage facility for the spent fuel with the capacity 6,000 tons has been built. A tunnel under the river Enisey for transportation of the liquid radioactive waste from the reprocessing plant to the new site of injection, has been built. The Russian Energy Strategy still envisages completion of the construction of RT-2, “if possible”. Capacity of the plant must be 1,500 tons annually, and capital investment was estimated in $3 billion.

Krasnoyarsk Mining Chemical Combine.

Out of all the accidents at the nuclear power plants the accident at the 4^th unit of the Chernobyl power plant, located to the south from Kiev, is the most devastative. The accident occurred on April 26, 1986, at about 1.24 a.m. Moscow time. Two explosions, following shortly one after another, blew off the reactor building, ejecting concrete, graphite and debris, and leaving a gaping hole. The reactor core was exposed to the outside air. The smoke and gases from the fire rose to the height over 1 km into the air, followed by a large amount of uranium fuel, transuranics and fission products from the reactor core, including induced activity isotopes and essentially all the noble gases. Radioactive materials were released from the reactor core into the atmosphere during the first ten days after the accident, before the releases could be contained. The heat from the fire resulted in releases of radioactive iodine (which resulted in thyroid cancer development in many of those who were in their childhood at the moment of the accident), volatile metallic elements like cesium and strontium, and other radionucleides, produced in the reactor in the process of its operation. The accident resulted in contamination of the rivers around Chernobyl due to atmospheric deposit from the accident and later run-offs from contaminated watersheds. The plume reached the Black and the Baltic seas. Most of the activity fell out over the land.

Chernobyl accident.

About 200,000 Russian citizens participated in clean-up works. After the accident territories of 19 regions were contaminated by ¹³⁷Cs and ⁹⁰Sr. In 15 years after the accident radiation situation in 12 regions is considered normal. But almost 2 million people still live in contaminated areas in 14 regions. As most radioactivity fell out in the rural areas, some covered by the forest and bogs, fires in contaminated forests and heathers result in new contamination. Only in Russia the agricultural area contaminated by radioactive cesium above 1 Ci/km² was about 3 million hectares. As admitted by the Russian Ministry on Emergent Situations, only in 1992-1998 measures on mitigation the consequences of the Chernobyl accident and payment compensations to the affected people cost the government more than $3 billion.

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Other accidents at nuclear power plants

1. Leningradskaya NPP

   A serious accident occurred in November 1975. A fuel assembly with nuclear fuel was destroyed due to the lack of water in technological channel. As the result, fission products and transuranic elements were released into the graphite cladding of the reactor. The discharge of radioactivity into the atmosphere continued during one month. By various estimates, from 137,000 to 1.5 million Curies were released into the environment. Tons of liquid radioactive waste were discharged into the Baltic sea. Following the accident, the radiation background in the city of Sosnovy Bor (5 km from the plant) varied from 600 microrem per hour to 8 rem per hour. Increased level of radioactive background was registered in Finland. Residents of the Baltic region were not informed about the accident.

   On May 1986 radioactive fall out was detected on the South Shore of the Gulf of Finland. 30 villages and towns were covered by radioactive rain. Radioactive background increased 10-15 times. Water in wells and rivers, local food products were contaminated by the radionucleides from the Chernobyl reactor. Radioactive iodine gave the most serious input into the effective dose.

   This is a research institute, accountable to Rosatom, that has a few research reactors and a pilot installation for production of the so called vibro-pack fuel – mixed plutonium and uranium fuel for breeder reactors. NIIAR is located in the city of Dimitrovgrad, in Ulyanovsk region, closely to the river Volga. In July-August 1997 one of the fuel assemblies at the reactor “Mir” lost its hermetic wholeness. Operators started to cool reactor and discharged radioactive coolant into the reactor pool. Inert gases from the pool started to emerge into the atmosphere, exceeding the permissible discharge 1.5-3 times daily. Besides the release of radioactive iodine started from the cooling pool. During 3 weeks the permissible discharge of ¹³¹I was exceeded 15-20 times daily. Residents of the region were not informed about the accident and did not get relevant treatment. Medical statistics data for 1985-1998 witnessed that morbidity rate of thyroid gland increased 7 times during this period.

2. NIIAR.

. It is located 80 km away from St. Petersburg, on the South Shore Of the Gulf of Finland and has 4 units. The first unit started operation in 1974. The first accident occurred two weeks after the start of the operation. On the 6^th of February, 1974 accident at the intermediate loop resulted in the release of radioactivity into the environment and killed 3 people.

Operating NPP inevitably and permanently contaminates the environment by the man made radionucleides. There are data about contamination of the soil and biota by ¹³⁷Cs and ⁹⁰Sr around Leningradskaya, Novovoronezhskaya, Kurskaya, Balakovskaya NPPs. Serious contamination exists around Beloyarskaya NPP, where the fast breeder reactor BN-600 is operated. In some years, for example, in 1992, the values of b -activity of snow and rain in the town, hosting the working force of Beloyarskaya NPP, increased 16 times. Concentration of tritium in Beloyarskya water reservoir is increased 2% annually. In 1981-1986 several times concentration of tritium in rain and snow fall out in the regional city of Ekaterinburg was increased 20 times. Factually surface and underground waters around all NPPs are contaminated by tritium. Tritium contamination can be found tens of km away from a NPP.

Contamination from the "normally" operating NPPs.

The fuel fabrication plant in Novosibirsk produces fuel for production reactors, highly enriched uranium fuel for research reactors, and fuel assemblies for WWER-1000 reactors. The plant is located 8 km away from the city downtown. A few years ago local scientists discovered drainage from the plant storage of liquid radioactive waste, outside the territory of the plant, into the area not limited for public access.

Fuel fabrication.

There are 4 enrichment plants in Russia: at the Siberian Chemical Combine in Seversk, near Krasnoyarsk (Zelenogorsk, formerly Krasnoyarsk-45), near Irkutsk (Angarsk), near Ekaterinburg in the Urals (Sverdlovsk-44). Information available on the enrichment plant in Zelenogorsk, can give an idea about the radioactive waste management at the enrichment plants in Russia and possible contamination from this type of activity. Solid radioactive waste is stored in special storage facilities on the site of the plant. Liquid radioactive waste is discharged into 2 pools located outside the plant territory. The volume of both pools is 29,000 m³. Scientists from the Institute of Geology of the Russian Academy of Sciences Siberian Branch investigated ecological situation around these pools. They discovered uranium in the pools and estimated its amount as 2 tons. In one of the pools, the scientists claim, there is drainage of water contaminated by uranium, in the direction of the closest river.

Enrichment plants.

Conclusions.

1. No facility of the nuclear fuel cycle can be considered as safe.

2. Long before the Chernobyl accident there occurred accidents at the reactors of nuclear power plants.

3. Accidents at and operation of the facilities of nuclear fuel cycle led to vast contamination of soil and water resources.

4. Nuclear industry is inclined to hide information about the accidents and contamination of the environment.

5. Citizens are not protected from radiological injury. They must be ready for new accidents and learn how to protect themselves.



31/05/2006