|Fig. 1: USSR stamp commemorating the K-3 class "Leninsky Komcomol," the first nuclear submarine of the Soviet Union. (Source: Wikimedia Commons)|
Following World War II, the practice of disposing nuclear/radioactive waste materials became widespread amongst developed nations. Between 1946 and 1993, thirteen different countries used ocean dumping as a method of disposal. However, in 1993, this practice was banned by international treaties as part of the The Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter 1972, also known as the London Convention. 
It has been reported that over 136,000 TBq of radioactive waste was dumped in the oceans during this time. The levels of dumping in the Arctic, the Atlantic, and the Pacific reached roughly 90,000 TBq, 45,000 TBq, and 1,278 TBq respectively.  These numbers are composed of both different types of waste and containment. Liquid waste was either unpackaged and diluted into surface water, or packaged and sunk. Solid waste was either composed of low level waste solidified with cement or bitumen before being sunk, or unpackaged components of previous nuclear installations. It is important to note that nearly 2/3 of the overall reported radioactive waste was dumped by the Soviet Union in the form of six submarine reactors, the shielding assembly from the nuclear icebreaker reactor, and spent nuclear fuel.
The severity of the Soviet Union dumping actions warrants a closer look into where their reported total of 797 TBq of nuclear waste was dumped into the oceans.  The dumping primarily occurred through land-based discharges of radioactive pollutants that would make their way to the sea through river runoff, accidents on land that led to further disposal through runoff, and intentional dumping by the Russian Navy. 
Disposal of nuclear waste through accidental occurrences on land is a small contributor to the overall waste numbers. However, intentional discharge was reported in cities such as Chelyabinsk, Tomsk, and Krasnoyarsk, where weapons producers would freely dump waste, only to flow downriver to the source of drinking water for many towns.  These rivers often discharge into the Arctic Ocean, causing further contamination beyond the intentional mass disposal outlined above. Contaminants released from nuclear producing facilities that entered these rivers include polyvinyl chlorides, heavy metals, and raw sewage, all harmful to the ecosystem and human health.  Further discharge injected directly into the ground has been estimated to have reached millions of curies.  While these practices reached their height between 1948 and 1952, the more profound nuclear impact on the Arctic and Pacific Oceans would occur through Navy dumping. 
Soviet disposal of nuclear wastes was profound in the Arctic ocean, releasing more than 90,000 Tbq as the sole nation dumping in this area. The full extent of Soviet dumping was reported by Alexey Yaklobov in a report published in 1993. The practice of regularly dumping liquid radioactive waste (LRW) began in 1960, carried out by vessels such as the nuclear submarine, the K-3, as seen illustrated in the USSR stamp commemorating the vessel in 1970, shown in Fig. 1.  Over time, more than 902 Tbq or LRW would be dumped in the Baltic (.0007 Tbq), White (3.7 Tbq), Barents (450 Tbq), and Kara (315 Tbq) seas. The dumping of solid radioactive waste began in 1964, primarily at low and intermediate levels of radioactivity. Most of this waste was produced in the operation of nuclear powered ships, submarines, and icebreakers. The total amount of radioactivity due to the above amounted to 574 Tbq in the Kara Sea and 1.5 Tbq in the Barents Sea, with the greatest amount of dumping occurring between 1983 and 1988. Russian Navy dumping didn't solely occur in the Arctic Sea, but also occurred in the Sea of Japan, through Soviet tankers' disposal of liquid nuclear waste, as well as the sinking of two nuclear submarine reactors, which accounted for 46.2 Tbq of activity. The total Soviet dumping in the Pacific Ocean amounted to 707 Tbq. 
The most damaging of the radioactive waste disposed was in the form of spent nuclear fuel found in sunken objects. These hold a hazardous mixture of fission products and actinides.  Enriched Uranium fuel naturally decays into plutonium, which is widely regarded as one of the most dangerous elements to the environment. Another byproduct of the spent nuclear fuel is Cs-137, which can bind to soils, and work its way through trophic levels. Because of the continuous decay into different isotopes, spent nuclear fuel becomes more hazardous as time passes. Nuclear reactors begin to contain a large multitude of different radioactive isotopes as they age on the sea floor. Because of the presence of metals in the uranium decay series, salts and oxides begin to form, which, when exposed to sea water, can easily diffuse. This makes the task of tracking the radioactivity difficult.  In complex ecosystems such as that of the Arctic Ocean, where the vast majority of Soviet dumping took place, this radioactive material can become embedded in the seafloor, trapped in ice, or enter the food chain.
It is important to understand the severity of Soviet radioactive waste dumping practices as we continue to learn more about the far reaching effects of the various radioactive isotopes that comes as a result of their continuous decay. With the implementation of the London Convention, regulation has helped to put an end to this activity. Now, much safer means of storing radioactive waste have been put into action that are constantly being improved upon. As the world begins to further explore reusable energy sources, nuclear energy provides an effective solution. However, we must look back on the vast quantity and practice of the Soviet Union in their disposal of such wastes as a learning lesson to be responsible moving forward.
© Matthew Stevens. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
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