Nearly 40 years ago, something happened in the quiet, unremarkable coal-mining town of Yunokomunarivsk in the central Donbas that made it the subject of urban legends.
On Sept. 16, 1979, the Soviet authorities detonated a nuclear bomb inside the “Yuniy Kommunar” (“Young Communard”) coal mine, at a depth of 903 meters, just beneath the town of some 22,000 people.
The subsurface nuclear blast had a yield of 300 tonnes of TNT, roughly 2 percent of that of the Hiroshima bomb. The experiment, many details of which are still classified, was designed to reduce buildups of stress in rock formations, and prevent methane explosions – a deadly hazard of mine workings.
For decades after the experiment, the “nuclear pit” of Donbas was carefully monitored by the Soviet and then independent Ukrainian authorities for any sign of a release of its radioactive debris.
But today, as the Kremlin’s war in the Donbas enters its fifth year, the mine is under the control of the area’s Russian-installed occupation authorities. They have announced that from April 14 they intend to stop maintaining the mine, and let it flood.
Should they do this, Ukrainian ecologists and military say, the Donbas may eventually face environmental disaster, with radioactive groundwater polluting much of the embattled region.
“Yuniy Kommunar”, or Yunkom as the locals call it for short, is located some 600 kilometers southwest of Kyiv, just east of the city of Yenakieve, a hometown of the ousted former pro-Russian Ukrainian president, Viktor Yanukovych.
Before the nuclear blast in 1979, Yunkom was considered the Soviet Union’s most dangerous coal mine because of increasingly frequent methane explosions, and unstable rock formations. According to official figures, between 1955 and 1979, there were at least 235 accidents at the mine, resulting in the deaths of 28 miners.
The Soviets had used nuclear explosions for non-military purposes in Ukraine before.
Back in July 1972, they detonated a 3.8-kilotonne bomb at a depth of 2,483 meters near the village of Khrestysche, near the border of Kharkiv and Poltava oblasts, in the hope of extinguishing a fire at a gas well. Codenamed “The Torch,” the mission failed, and sent a mushroom cloud of burning gas mixed with rock debris 1 kilometer into the sky. The fire was eventually extinguished a few months later using conventional means.
In total, between 1965 and 1988, the Soviet authorities conducted at least 124 “peaceful nuclear blasts to benefit the union’s economy” under the classified “Program No. 7.” At least three of the operations ended up causing massive releases of radioactive fallout.
There was no release of radioactive fallout at the Yunkom mine, but the nuclear blast’s enormous heat and pressure formed a 30-meter-long glassy cavern filled with some 600 cubic meters of highly-radioactive water at the very bottom of the pit.
The mine resumed working only a day after the nuclear blast, however, and ever since then the hazardous radioactive cavern was carefully maintained and monitored. The work did not stop even amid the severe economic slump that his post-Soviet Ukraine in the 1990s.
In an official report to Ukraine’s government in 1999, the then minister of ecology, Vasyl Shevchuk, warned that without proper maintenance and water pumping at the mine, the radioactive water might eventually break out of the cavern and cause the radioactive contamination of the region’s water basins.
In 2001-2002, Yunkom was eventually closed down, along with dozens of other unproductive coal-mining enterprises in the Donbas. Nevertheless, water pumping continued at the mine, even though the cost of maintenance reached $45 million a year.
Until 2013, Ukraine’s Ministry of Ecology continued to take soil and water samples near the Yunkom mine to monitor radiation levels.
But with the outbreak of Russia’s war in the Donbas in spring 2014, Ukraine lost control of the hazardous nuclear pit, monitoring work ceased.
Today, with a 400-kilometer front line still dividing the region in half, the Yunkom mine is located some 20 kilometers into the Kremlin-occupied territory. It is just one of several industrial sites in the Donbas that have the potential to cause serious damage to the environment should there be an accident.
In late November 2017, the Organization for Security and Cooperation in Europe (OSCE) presented a report saying that up to 36 decommissioned coal mines in the occupied Donbas were not being properly maintained, and were threatened with flooding and collapse.
The Yunkom mine was seen as one of the worst threats.
According to the OSCE experts, further collapses and flooding of mines could cause massive releases of chemicals into groundwater, and contamination of the region’s largest rivers, such as the Kalmius, Kalchik, and Siverskiy Donets.
The Russian-installed occupational authorities have already stopped maintaining many other old coal mines.
On June 24, 2017, they ordered to halt to pumping at the “Poltavska” and “Yenakiyivska” coal mines – both located just 5-6 kilometers of the Yunkom mine – starting from July 1.
Three days after, local people in the occupied town of Yunokomunarivsk held a rally to protest at the decision – an extremely rare event in the Russian-occupied Donbas. According to the protesters, the flooding of the “Poltavska” and “Yenakiyivska” mines could also cause the collapse of the nearby “nuclear pit.”
During the rally, video footage of which was uploaded to YouTube, an official from the occupation authorities said it had already been decided to let all the mines in the area flood.
The official said the decision had been taken “in conjunction with representatives of a scientific center in Saint Petersburg” who had been engaged in restoring and decommissioning mines in the Donbas since 2015.
“Billions (in funds) are needed to restore and sustain the mines,” the official told the local protesters. “There’s not where to get that money. Russia won’t invest in destroyed mines.”
Nearly a year after the rally, on March 24, the Kremlin’s occupation authorities ordered the start of the dismantling of the water pumps at the Yunkom mine, and to allow it to start flooding on April 14.
During an appearance on a local Russian-controlled TV channel on March 30, another member of the Russian-installed occupation authorities, Ihor Vitchenko, claimed that the Kremlin had been spending 11 million Russian rubles ($178,000) a month to maintain the Yunkom mine, while a complete overhaul of its safety equipment would cost at least 670 million rubles ($10.8 million).
For the occupation authorities, that was simply too much.
They made no secret of the fact that the decision to flood the Yunkom mine had been made in Russia, at Russian federal state institutions.
On Feb. 18, a Russian-controlled media outlet reported that three Russian institutions had taken part in the decision-making process – the private agency Institute Shachtproekt, based in Saint Petersburg, along with a joint stock company called VNIPI PromTechnologiya and a federal state budgetary institution called GidroSpetsGeologiya – both based in Moscow.
Their decision was that the “nuclear pit” should be flooded, and this would not cause any leaks of radioactivity into the ground. According to them, the flooding process will take approximately five years, after which the old coal mine will collapse into itself, thus burying the nuclear cavern at a depth of 1 kilometer forever.
Ukraine’s Ministry of Ecology and Natural Resources takes a different view.
The ministry believes the natural rising of groundwater to the earth’s surface may eventually cause the hazardous nuclear cavern to collapse and release its radioactive waters into the Donbas water basin.
However, the ministry’s experts say that forecasting the effects of the flooding of the Yunkom mine is extremely difficult, as no proper studies of the nuclear cavern’s condition have been made since 2013.
Ukraine’s Ministry of Defense agrees. During a briefing on April 2. Ukraine’s top military officer in charge of ecological issues, Colonel Maksym Komisarov, also said that the flooding of the Yunkom mine could result in a region-wide disaster.
Independent experts have a range of predictions concerning the fate of the infamous “nuclear pit” of the Donbas.
Speaking to Radio Svoboda on April 11, Ukrainian hydrologist Yevgheniy Yakovlev said that main source of danger in the radioactive cavern’s water were radioactive cesium and strontium. According to 1979 estimates, the level of radioactivity at the pit’s bottom reached 100 curies; however, after some 40 years of radioactive decay, the level may now be down to some 50 curies.
“The rock layers surrounding (the nuclear cavern) are weakened by water saturation,” the scientist said.
“There might be slow erosion, or possibly a rapid collapse of (the cavern) and the release of some 600 cubic meters of radioactively contaminated water into the Yunkom mine.”