Threat of the Dnieper reservoirs

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The water reservoirs of the Dnieper River in Ukraine pose a significant threat of a large-scale human-made disaster if their dams fail. Such a threat is typical for reservoir dams; however, the Dnieper reservoirs are especially dangerous because of the geographical conditions, as well as the consequences of the Chernobyl disaster and other nuclear-related environmental threats in the region.

While the safety studies of each dam are regularly performed and the public assurances about individual dam's condition were given multiple times,^[1] the comprehensive analysis of the overall safety of the dams as a system or the impeding dangers that the damaged dam would cause has never been performed to this day. Various different scenarios of what would happen in case of the dam damage predict the catastrophes varying only by the scale (provided that one of the dams would indeed break down). According to the worst predictions and taking into account the already available radioactive contamination, a dam accident may result in a major threat for significant territories of Ukraine, and, possibly, the Black Sea basin.

[edit] The reservoirs

During the Soviet era, the Ukrainian part of the Dnieper River flow was turned into a system of hydroelectric power plants by forming of five artificial reservoirs. Listed downstream, these reservoirs are:

• Kiev Reservoir (alias Kiev Sea)
• Kaniv Reservoir
• Kremenchuk Reservoir
• Dniprodzerzhynsk Reservoir
• Dnieper Reservoir
• Kakhovka Reservoir

The creation of reservoirs significantly boosted the Soviet energy industry and created a deep-water route on the river, formerly innavigable in certain sections. However, by diminishing flow velocity and altering river flow (see Irpin River), the reservoirs caused environmental problems such as adverse changes in the balance of aquatic life forms, coastline erosion, and many others. The evacuation of significant territories now covered by the reservoirs was costly, and later, the system proved to be economically ineffective,^{[citation needed]} as reservoirs’ waters began flooding important objects, most notably mines in the Nikopol region.

[edit] The hyperflooding risk

Landsat satellite photo of the Kiev Reservoir.

Like with other reservoirs, Dnieper reservoirs pose a potential threat of causing major flooding if their dams fail. Such damage may be inflicted by a powerful natural disaster (e.g., an earthquake), a human-made disaster, or a deliberate attack by terrorists or enemy forces at war.

The dams are supposed to be strong enough to survive natural and terrorist threats. Both their construction schemes and government efforts work towards this goal. For instance, some engineers guarantee that every Dnieper dam will survive an earthquake (to its typical regional extent), meteorite or aircraft falling.^[1] There are also countermeasures against overflooding and malfunction of dams. Authorities pay significant attention to safeguarding the dams and bridges by special units of the Ministry of Internal Affairs and other security agencies.^[2]

However, the Dnieper reservoirs pose a special risk by the fact that they form a cascade with an atypically short distance between them. In the case of one upper dam failure, massive flooding will impact other dams within hours, subsequently releasing lower reservoirs to the Black Sea. A similar disaster occurred with the Banqiao Dam, resulting in a cascade of 62 dam failures. Assessments of losses in a possible Dnieper hyperflooding vary, but remain very pessimistic.^{[citation needed]}

In case of a dam failure, floodwaters may devastate densely populated areas around Dnipropetrovsk, Zaporizhzhia and Kherson, forcing evacuation and possibly killing millions, and destroying major industrial areas. A failure of the Kiev Reservoir would cause a flooding of the low-lying areas of Kiev, mainly densely-populated residential neighborhoods.^[3] The aftermath of a possible complex flooding also include the widespread contamination by industrial and urban wastes and creation of swamps on bottoms of emptied reservoirs.

The first concerns about possible hyperflooding were raised in the 1980s.^{[citation needed]} In 2001-2003 the Security Service of Ukraine organized exercises on the Kiev Hydroelectric station, simulating a possible terrorist attack. The results of the exercises were considered satisfactory.^[3]

[edit] The reservoirs as a radioactive hypercontamination threat

Discussion of possible hyperflooding revealed another much more significant threat when hypothetical details of the incident were studied. First of all, a release of each but the southernmost reservoir would damage several top-hazard nuclear sites in the Dnieper basin, as explained below. Subsequently, the whole Black Sea area would be radioactively contaminated to a significant extent. This would cause a Europe-wide nuclear disaster by means of large-distance air and water circulation.

[edit] The Kiev Reservoir threat

Map showing caesium-137 contamination in Belarus, Russia, and Ukraine (in curies per square kilometer). Note the significant contamination areas along the Dnieper River flow.

After the Chernobyl Nuclear Disaster in 1986, radionuclides washed away by rains contaminated the bottom silt of the Kiev Reservoir. During the years following the disaster, there were suggestions to drain the reservoir because it was too shallow. It appeared that, if done, this could have caused the tremendous amounts of silt to turn into radioactive dust, free to be dispersed by wind. In that case, scientists predict even more serious disaster than hyperflooding.^[3] According to some assessments, dust clouds would devastatingly contaminate the whole Europe. Some scholars regard such disaster as the terminal one.^{[citation needed]}

Authorities reassured that the dangerous silt poses no actual danger if reservoir kept intact, and dismissed the draining plans.^[4] But this has re-energized concerns about accidental release of the Kiev Reservoir (and all subsequent reservoirs).^{[citation needed]}

[edit] The nuclear industry sites under threat of possible flooding

The cities of Dnipropetrovsk Oblast, standing on the Dnieper, contain dozens of hazardous industrial sites, mostly toxic wastes dumps, which may be destroyed not only by hyperflooding but also by weather extremes due to their poor protection.

The most dangerous among those sites are the radioactive dumps in the riverbank city of Dniprodzerzhynsk. The now-defunct Prydniprovsky Chemical Plant (PHZ) has been enriching uranium ores for Soviet nuclear program from 1948 till 1991, preparing the so-called Yellowcake substance. Its processing wastes are now stored in 9 open-air dumping grounds containing about 36 million tones of sand-like low-radioactive material, occupying area of 2,5 million square meters. The sites, improperly constructed from the very beginning, have been abandoned by industry long ago and remain in very poor condition. The top concern is the dumps’ closeness to both the Dnieper River and city residential areas. According to government experts, the dams separating the grounds from soil water are already leaking, causing the pollution of Dnieper basin. It is believed that further deterioration of the dams in itself may cause a devastating radioactive mudslide. Ukrainian government is now acquiring control over the grounds and seeking international aid in projects, aimed at securing and gradual re-processing PHZ wastes. Recently, the International Atomic Energy Agency has evaluated the condition of the sites and is considering a major observation&aid mission to Dniprodzerzhynsk.^[5]

Ukraine’s uranium ore mines (which products have been enriched by PHZ) are also situated in Dnipropetrovsk Oblast in proximity of the Dnieper and its tributaries, particularly in the town of Zhovti Vody.

The Zaporizhzhia Nuclear Power Plant is also situated within miles from the Dnieper, in the left-bank city of Enerhodar.

In case of a hyperflooding, hazardous materials from these and many other industrial sites may be poured on surrounding territories and the Black Sea.

[edit] Government position and recent concerns

The safety issue of the Dnieper reservoirs has never been discussed on a state level during Soviet rule. It was only in 1990s when authorities of independent Ukraine acknowledged the discussion officially. However, Ukrainian government never admitted the threat being a real one. Occasional concerns about underfunding of the dams-operating state company were raised in early 2000s, but the issue has been settled.^{[citation needed]}

New concerns arose in 2005 after a fake terrorist threat case. A police officer, dissatisfied with his commanders, anonymously called an emergency line stating that he had planted a bomb in a cargo train crossing the Kiev Reservoir's dam. An immediate check proved the threat to be fake and the alerter was arrested. But the incident caused another wave of public concern.^[6]

On May 30, 2006 researcher Vasily Kredo alerted the nation again, calling the Kiev Reservoir “the most dangerous place on the planet”. The researcher says there is a remote possibility of a “radioactive tsunami from the Kiev Sea” that would kill 15 million and make Ukraine “never revive again”.^[7]

[edit] See also

• Dnieper Hydroelectric Station
• Operation Chastise
• nuclear industry
• Chernobyl compared to other radioactivity releases
• Chernobyl disaster effects
• Chernobyl Heart
• Chernobyl in the popular consciousness

[edit] References

Notes

Bibliography

• (Russian) "The strange initiative", Kievskiye Vedomosti, January 31, 2002
• (Russian) Chernovetsky will check "the most dangerous place on the planet", Korrespondent.net, July 19, 2006

[edit] External links

• Battle of Chernobyl: The Consequences - details about the radioactive contamination