Leaching of radionuclides from furfural-based polymers used to solidify reactor compartments and components disposed of in the Arctic Kara Sea

Within the course of operating its nuclear navy, the former Soviet Union (FSU) disposed of reactor vessels and spent nuclear fuel (SNF) in three fjords on the east coast of Novaya Zemlya and in the open Kara Sea within the Novaya Zemlya Trough during the period 1965 to 1988. The dumping consisted of 16 reactors, six of which contained SNF and one special container that held ca. 60% of the damaged SNF and the screening assembly from the No. 2 reactor of the atomic icebreaker Lenin. At the time, the FSU considered dumping of decommissioned nuclear submarines with damaged cores in the bays of and near by the Novaya Zemlya archipelago in the Arctic Kara Sea to be acceptable. To provide an additional level of safety, a group of Russian scientists embarked upon a course of research to develop a solidification agent that would provide an ecologically safe barrier. The barrier material would prevent direct contact of seawater with the SNF and the resultant leaching and release of radionuclides. The solidification agent was to be introduced by flooding the reactors vessels and inner cavities. Once introduced the agent would harden and form an impermeable barrier. This report describes the sample preparation of several ``Furfurol'' compositions and their leach testing using cesium 137 as tracer

Radioactive Legacy of the Russian Pacific Fleet Operations. Final Report

There have been extensive studies of the current and potential environmental impact of Russian Northern fleet activities. However, despite the fact that the total number of ships in both fleets are comparable, there have been very few studies published in the open literature of the impact of the Pacific fleet. This study of the Pacific fleet's impact on neighboring countries was undertaken to partially remedy this lack of analysis. This study is focused on an evaluation of the inventory of major sources of radioactive material associated with the decommissioning of nuclear submarines, and an evaluation of releases to the atmosphere and their long-range (>100km) transboundary transport

Reactivity accident of nuclear submarine near Vladivostok

After the collapse of the Soviet Union and consequently the termination of the Cold War and the disarmament agreements, many nuclear warheads are in a queue for dismantling. As a result, substantial number of nuclear submarines equipped with ballistic missiles will be also withdrawn from service. However, Russian nuclear submarines have suffered from reactivity accidents five times. In the paper, a reactivity accident on a nuclear submarine that happened at Chazhma Bay located between Vladivostok and Nakhodka on August 10, 1985, has been described. In addition, the characteristics of submarine nuclear reactors, procedures of refueling, and the possibility of a similar accident are given. Further, the radiological risk to Japan and neighboring countries has been assessed by using an atmospheric pollutant transport code, WSPEEDI, developed by Japan Atomic Energy Research Institute. The radiological risk has been evaluated for the Chazhma Bay accident and for a hypothetical reactivity accident of a retired submarine during defueling, assuming winter meteorological conditions. The analyses have shown that the radioactive material might be transported in the atmosphere to Japan in one to several days and might contaminate wide areas of Japan. Under the assumptions taken in the paper, however, the radiological dose to population in the area might be not significant

Furfural-based polymers for the sealing of reactor vessels dumped in the Arctic Kara Sea

Between 1965 and 1988, 16 naval reactor vessels were dumped in the Arctic Kara Sea. Six of the vessels contained spent nuclear fuel that had been damaged during accidents. In addition, a container holding {approximately} 60% of the damaged fuel from the No. 2 reactor of the atomic icebreaker Lenin was dumped in 1967. Before dumping, the vessels were filled with a solidification agent, Conservant F, in order to prevent direct contact between the seawater and the fuel and other activated components, thereby reducing the potential for release of radionuclides into the environment. The key ingredient in Conservant F is furfural (furfuraldehyde). Other constituents vary, depending on specific property requirements, but include epoxy resin, mineral fillers, and hardening agents. In the liquid state (prior to polymerization) Conservant F is a low viscosity, homogeneous resin blend that provides long work times (6--9 hours). In the cured state, Conservant F provides resistance to water and radiation, has high adhesion properties, and results in minimal gas evolution. This paper discusses the properties of Conservant F in both its cured and uncured states and the potential performance of the waste packages containing spent nuclear fuel in the Arctic Kara Sea