April 8, 2024
IMAGE: A handheld Geiger counter. (Photo by Dean Calma / IAEA)
We knew something was not quite right in the country when the calls started coming in from all around Georgia. It was like an unfolding and scattered disaster, one caused by orphaned radioactive sources.
An early case emerged at the Lilo military base near Tbilisi. Eleven new recruits were showing clear signs of radiation burns. The military doctors who treated the soldiers did not understand how they got their wounds. There was no information about radioactive materials stored at the base. The real cause of the mentioned symptoms—initially acute and then chronic radiation sickness—could not be determined in time. It took several months after the first examination by doctors. The precise circumstances of the accidental exposures were extremely difficult (and often impossible) to reconstruct. How could soldiers get radiation burns on a base where there were no radioactive materials? What was the source of the radiation? How did the radiation source get to the base? The Georgian government had no answer.
After initial treatment in France and Germany, 11 patients could reasonably be considered recovered, or at least their wounds to be in later stages of healing. Subsequent careful observation, unfortunately, did not confirm this optimistic forecast. Considering the necrotic lesions, the doses they received probably exceeded 25 grays. They faced serious deterioration in their quality of life, resulting from disfigurement from scarring or loss of functionality because of amputations. The soldiers, injured during public service, would require expensive treatment for the rest of their lives.
I met them five years after the incident. In my official capacity, I was tasked with preparing letters of support to finance further treatment at clinics abroad and to compensate them for material losses. I felt anger, despair, and helplessness. Healthy young men were drafted into the army by government and then returned to their families with serious radiation sickness. They were not victims of nuclear weapons or a disaster at a nuclear power plant. This tragedy would not have happened if responsible people had followed elementary radiation safety rules.
Since 1951, the commission under the Presidium of the Academy of Scientists of the Soviet Socialist Republic of Georgia had been leading the work on issues of peaceful use of atomic energy in Georgia. While not a nuclear country, Georgia had at that time advanced scientific and research radiological infrastructure in medicine, biology, space materials science, and agriculture. All directions related to radiation in the Soviet Union were managed centrally from Moscow. The development of nuclear and radiological weapons was one of the priority and classified areas in the Soviet Union, and therefore the transit of military purpose or dual-use radiological sources went around national institutions.
Ten years had passed since the collapse of the Soviet Union, and Georgia had regained its independence. When the Soviet system collapsed, it did not leave behind institutions and personnel that were organized to respond to radiological incidents. When Russian troops abandoned their bases in 1992, however, they left behind scores of radioactive sources and failed to tell anyone about them.
As a result, the unsuspecting Georgian government and first minister of natural resources and environmental protection of Georgia, Nino Chkhobadze, had to respond to numerous radiological accidents with the heaviest consequences. Most of these sources clearly presented a potential high security risk. The country needed authorities to respond to radiological incidents.
I was doing research work in the Soliton Physics Department of Tbilisi State University when, in 1999, I received an offer from the Ministry of Natural Resources and Environmental Protection to work in the Nuclear and Radiation Safety Service. The service was to be created and staffed mainly by physicists. Under the leadership of the minister, a council of advanced scientists in the field of radiation was created, which would develop recommendations for difficult cases. I was a member of this council and was the national liaison officer between Georgia and the International Atomic Energy Agency (IAEA).
Before joining the ministry, I was not aware of any radiological incidents in the country. They were not widely reported. My experiences were related to the development of radiation safety in the medical field, but I found myself actively involved in the system for responding to radiation emergencies.
On August 26, 1997, several months after soldiers first reported the mysterious burns, a Georgian army radiology team detected high levels of radiation near an underground shelter on the Lilo military base. A group of Georgian scientists from the Andronikashvili Institute of Physics—Zura Saralidze, Noe Katamadze, and Shukri Abramidze—soon discovered that the Lilo base was littered with so-called orphan sources. These are lost, stolen, or abandoned radioactive sources.
The sources found at Lilo were used by the Soviet military to train for nuclear battlefields, according to Abel González, then director of nuclear safety and waste at the IAEA. Radiological devices were buried around the Lilo base so that by conducting maneuvers in a contaminated site, soldiers could learn how to calibrate equipment used for radiological monitoring in the event of nuclear accidents or a nuclear war. They could conduct radiation reconnaissance, practice combat operations under the conditions of the use of nuclear weapons, and train for how to deactivate military weapons and equipment.
After the Russian troops left, the Georgians later turned the base into a training center for border guards. They had no idea there were radioactive materials on the base.
After the first radiation measurements were carried out at Lilo in August, 1997, the president of Georgia, Eduard Shevardnadze, issued an order to create a national working group of specialists to conduct a radiological investigation.
On September 13, two days after the investigation began, a source of radiation was found in a pocket of a winter coat worn in turn by soldiers while standing guard. It was a small metal cylinder of cesium-137, with a dose rate of about 45 millisieverts (mSv) per hour at a distance of one meter (world average background radiation is 2.7 to 3.4 mSv per year). Subsequent measurements showed there was no additional contamination in the immediate vicinity. But a slightly elevated background radiation nearby led to the discovery of another radiation source buried 20 centimeters below a football field. An even greater number of sources were also found near the smoking area.
After these discoveries, Georgia’s minister of health asked the IAEA to help treat the soldiers and send a team of its specialists to the base to assess the radiological situation.
The first IAEA team arrived in Lilo on October 11, 1997. They helped find more sources and conducted a radiological survey of the site. They also confirmed that the radioactive sources discovered so far—including 12 cesium-137 sources and a number of radium-226 sources—were in lead containers and kept safe. After the Georgian task force completed its investigation of the base, President Shevardnadze created a national commission to inspect other Georgian military bases. By November 1997, the commission had identified 352 radiologically contaminated sites.
In one case, the commission found dozens of sources of cesium-137 at the former Soviet missile base in Vaziani. Seven sources were found in spent nuclear fuel storage. Apparently, these devices were found elsewhere in 1993 and then moved to storage.
In July 1998, several more discoveries were made. Three abandoned springs were discovered in the village of Matkhoji, 300 km west of Tbilisi. Parts of the former Soviet military base near Kutaisi were contaminated with radium-226. Two radioactive sources were discovered at the military base in the city of Poti near the Black Sea.
The worst was yet to come. In October 1998, extremely strong sources of strontium-90 were discovered near the village of Khaishi in western Georgia.
In December 2001, I sent a message to the IAEA conveying a request for technical support. Three lumberjacks found containers with highly radioactive materials in a forest in a mountainous region near the village of Lia. They were hospitalized in serious condition with radiation burns. The dose they received was equal to 2-6 grays. Villagers living nearby were thrown into panic and started to report headaches and other symptoms.
Finally, it was found out that the radioactive sources were so called RTG-90, a specific type of thermoelectric radioisotope generator (RTG) with a strontium-90 isotope charge. Identical sources of RTG-90 had been found in the Svaneti region between 1998 and 1999. In Soviet times, various radioisotopes and radioactive sources were used as sources of heat in thermoelectric energy transformers. The design of an RTG is simple by the standards of nuclear technology. The main component is a sturdy container of a radioactive material (the fuel). Thermocouples are placed in the walls of the container, with the outer end of each thermocouple connected to a heat sink. Radioactive decay of the fuel produces heat. The temperature difference between the fuel and the heat sink allows the thermocouples to generate electricity.
These RTGs contain 35,000 to 40,000 curies of activity. The radiation dose at a distance of one meter from the surface of the source is 100 roentgens per hour. For reference, the average annual background radiation is roughly 0.2–0.3 roentgen every year. It is fatal to stay nearby. I took measurements when the sources were safely allocated in lead containers, and I still remember the warmth that I felt with my hand when approaching the surface of the container.
The Ministry of Natural Resources and Environmental Protection of Georgia, under leadership of Minister Chkhobadze, extensively collaborated on the challenge of recovering orphan sources—including working with the IAEA, the US Department of Energy, several embassies, independent experts, and journalists. Georgia received extraordinary international support. I remember a strategic meeting in the minister’s office when Mohamed ElBaradei, director general of the IAEA, visited Georgia. Maps were laid out in preparation for the international search operation, along with the list of devices and the preliminary planned dose for responders.
The major cause of the incident was the improper and unauthorized abandonment of eight Strontium-90 radioactive sources in Georgia. Only six have been found so far.
In 2005, I participated in the Racha expedition, where Georgian and IAEA experts searched for lost radioactive sources. Radiation safety takes teamwork, and of course an international team is better.
During the Soviet period, there was a special paint factory in the village of Iri. The factory was a closely guarded secret, as it produced paint for military planes. Arsenic mines were located near the village. After the collapse of the Soviet Union, the factory was closed. The Russians took away anything of value. The place was deserted. Few families were left in the village.
Our expedition was testing a new type of search device, a radiation detector in a rucksack. When I walked with it on my shoulders and when our car drove slowly, it monitored the area for radiation. Passing by a house in Iri, an alarm sounded. We went into the yard to conduct a detailed search. We went into the courtyard, and the level of radiation was increasing. To our surprise, on top of a faucet over a sink, on a small shelf, next to the soap, where they washed their hands every day, we found a jar with bolts and wires in it. The jar also contained a powerful cesium source, hiding in plain sight in an otherwise harmless environment.
My colleagues and I calmly continued our recovery operation and searched for orphan sources throughout the courtyard. We explained to the residents of the house that there are health risks associated with living near a radiation source. They were surprised. The residents of Iri thought that the cesium source was a piece of iron that could be used for something and had no idea about the radiation risks.
We placed the source in a container, loaded it into the service car for removal, and continued driving. After one kilometer, we found another radioactive source in a pile of wall debris. It was in a small, half-destroyed building next to a field where local children were playing football. Here, the level of background radiation was 12 times higher than in the center of the village. We cordoned off the building with yellow tape, used a FieldSpec spectroradiometer to identify the source, and assessed the threat. We identified both of the sources that we found as cesium-137, a strong gamma emitter. The origin of the sources is unknown.
Georgia’s experience revealed the failures and weaknesses of the national radiation safety regime. This is not unique to the Soviet radiation “heritage.” Lack of information is the main cause of preventable radiological incidents. These types of incidents could occur anywhere.
Radiation safety practices also constantly evolve. National resources are not sufficient for someone to become a qualified radiation safety expert. Georgia received incredible international assistance, including trainings, scientific visits, expert missions, and IAEA technical documents, as well as technical support from the IAEA, US Department of Energy, European Union countries, and other international organizations. At that time, our human and technical resources were not enough for the scale of the challenge. The international assistance provided to the Georgian Nuclear and Radiation Safety Service is all the more appreciated because we worked with foreign colleagues in all radiation-dangerous situations in west Georgia, on former Soviet military bases, and to develop national radiation safety infrastructure.
These were difficult years. My country unfortunately became known for radiological accidents. As a specialist, I look back on this time as an intense experience with some tragic lessons. This is not just a technical job. I am responsible for the health and well-being of my fellow citizens. I try to impart that wisdom to future specialists who would follow my path. I also try to ensure that they have better working conditions, appropriate education, and the opportunity to get acquainted with the best international practices.
In this way, our legacies—from those who worked so hard to clean up this Soviet radiation heritage—are to help prepare others for how to prevent and respond to such challenges.
Lia Chelidze, PhD, works at the Tbilisi State University Andronikashvili Institute of Physics. She is president of the Georgian Health Physics Chapter and a member of the Commission of Nuclear Energy and Radiation Safety (GNAS) of the National Academy of Science of Georgia. Until December 2014, she was leading the Nuclear and Radiation Safety Department at the Ministry of Environment and Natural Resources of Georgia. Her primary areas of expertise include nuclear and radiation safety, state regulations, and waste management. She served as a liaison officer between Georgia and IAEA and worked on safeguards applications in regard to the Nuclear Non-Proliferation Treaty.
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