This paper is based on computational and experimental work and expeditions conducted in 1985-1992 by staff of the Russian Scientific Center "Kurchatovskii institut," the Chemical and Medical Services of the Pacific Ocean Fleet, and some other institutes and organizations in Primor'e. These data served as a basis for a section in the "white book" -a report by A. V. Yablokov's commission on the disposal of radioactive wastes in the seas washing Russia's coasts.* The nuclear society plans to publish a monograph containing the basic information in these works.Reactivity Accident and Its Consequences. A serious radiation accident occurred on August 10, 1985 in a nuclear-powered submarine moored at a pier at a dockyard in Chazhma Cove for repairs (Primor'e, town of Shkotovo-22): after the reactors were refueled a spontaneous chain reaction occurred in the starboard reactor due to a violation of nuclear safety rules and technology of the explosion of the reactor cover. As a result of a thermal explosion the bow and stern equipment compartments were destroyed, part of the fresh fuel was thrown out of the reactor, the reloading house was destroyed (its roof was thrown 70-80 m away and fell into the water 30 m from shore), and the submarine suffered damage to the pressure hull in the stern part of the reactor bay. Immediately after the explosion a fire broke out in the reactor bay. It took 4 h to contain the fire, after which a radiation inspection of the territory of the dockyard and the automobile roads *The facts and problems associated with the disposal of radioactive wastes in the seas washing the coasts of the Russian Federation (the materials of the report of a government commission).

The radioecological conditions which developed on the territory over the long operating time of the object of the naval fleet in Guba Andreev are described. The results of an analysis of the sources of the real and potential danger and measures to prevent dangerous effects for the environment and the workers at the time remediation work is performed are discussed.The buildings and structures at a temporary disposal site for spent nuclear fuel and radioactive wastes in Guba Andreev (a former technical shore base of the northern fleet) were built at the end of the 1950s -beginning of the 1960s. Since spent fuel was added to the disposal site well before the fuel was shipped out, a large amount of fuel (~100 reactor cores from submarines) and radioactive wastes have accumulated at the site. For more than 40 yr of operation, the buildings and structures were not maintained, so that the states of many storage sites are unsafe [1]. Because the storage sites have become leaky, radioactive substances are flowing into the ground waters on the territory. Melted snow and rain water are gradually expanding the zone of contamination and are carrying radionuclides into the water of Guba Andreev.Determination of the Radioecological State of the Territory and Water Area. Periodic examinations of the buildings, structures, territory, and water area of Guba Andreev were conducted by the radiation safety services of the fleet and by specialists from the Research and Design Institute of Electrical Technology (ground survey) and the Russian Science Center Kurchatov Institute (water area). In 2002-2004, the free financial assistance provided by the Norwegian Radiation Protection Agency made it possible to construct cartograms of the radiation contamination ( Fig. 1) and perform hydrogeological and radiation-geological examinations of a large part of the territory of the disposal site. These measurements differed quantitatively and qualitatively from previous measurements: the number of measurements performed on soil samples was ten times larger than the number performed in preceding years, extensive field investigations made it possible to construct cartograms of the γ-ray field of the territory and water area and to identify the locations of sources of radioactive contamination and determine the radionuclide composition. On the basis of these results, a three-dimensional database containing information on the sources of radioactive contamination of the territory, buildings, and structures was constructed. This database can be used to estimate the real and potential sources of radioecological danger and to plan work on eliminating them.

The construction of floating nuclear power plants began in the interests of supplying energy in remote far-north and far-east regions in our country which are difficult to reach. A predictive assessment of radiological and radioecological consequences of operating such plants is extremely urgent. The problem is examined on the basis of the effects of a floating nuclear power plant on plant workers, the public, and the environment that have been determined by a computational method at the design stage as well as on the basis of generalization and analysis of experience gained in operating nuclear powered ships under the difficult climatic conditions in the Far North and Far East over the last 45 years.The regions of the Far North and the remote regions associated to them occupy more than 50% of the territory of Russia. Local autonomous energy-supply systems, which will not become a part of a unified energy system of the country any time soon and which require continual deliveries of fossil fuels, allow approximately 20 million people to survive and industry to develop. Technical and economic investigations performed for the Far North and Far East have shown that is economically advantageous to develop and use in these regions floating nuclear heat and power plants (FNHPP) as alternative sources of energy.A floating power generating unit is the base unit for generating 60 MW(e) of electric energy and 150 MW(t) of thermal energy. It includes two KLT-40S facilities with water-moderated water-cooled reactors in a strong sealed protective envelope, designed to confine an accident with rupture of the first-loop pipeline.Even though similar reactor systems (OK-900, KLT-40, -40M) with total production of about 250 reactor years and several hundreds of shipborne reactors have been operating reliably and safely for several years in icebreakers and nuclearpowered submarines, the problem of ensuring the radiological and radioecological safety of FNHPP remains at the center of attention. The present article is devoted to an examination of these questions.Safety [1]. In developing FNHPP, priority is given to accident avoidance and radwaste reduction. At the same time, measures are being implemented to increase the reliability of safety systems, and technical means for controlling unanticipated accidents, including serious accidents with cord damage, are being adopted.

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