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A large number (~20000) of spent fuel assemblies from the reactors of submarines of different generations have accumulated in three closed storage facilities of the Zaozerskii Affiliate of the Northern Federal Enterprise for Radwaste Handling [1,2]. These storage facilities are buried tanks holding 260 or 300 mm in diameter tubes (cells) positioned vertically. The space between the tubes is filled with concrete. Each storage facility contains about 1000 cells, each cell holding seven fuel assemblies in special jackets. As a result of prolonged (more than 20 years) storage under unregulated conditions, groundwater and atmospheric precipitation have entered many cells, which has caused substantial degradation and unsealing of a substantial number of fuel assemblies. It is important to measure the radioactive aerosols in the storage facilities and directly inside cells with fuel assemblies in order to evaluate the degree of radiation danger of the work to be performed and could be helpful for determining the unsealing of the stored assemblies.Volatile 137 Cs was used in the measurements as an indicator of the degree of unsealing of the fuel assemblies. Aerosol samples with prescribed volumes from air pumped from a cell being examined with internal volume ~1.2 m 3 were obtained using an apparatus which we developed. This apparatus consists of a PVP-04A sampling device with rubber liners, which reliably seal the joints between the tubes of these storage cells and the entrance opening of the PVP-04A apparatus. Figure 1 displays a diagram of the transitional flange with the seals.Replaceable AFA RSP-20 filters with 0.2 mg/cm 2 thick LFS-2 filtering material and 10% slip-through coefficient with average diameter of the oil fog particles 0.34 µm (according to OST 98 10052-84 data) were used to obtain aerosol samples. In each sample extraction, 200 liters (0.2 m 3 ) of air was pumped through the replaceable filter at a rate of 100 liters/min. The fact that almost all of the aerosols studied were caught during pumping was checked when the storage facility was examined with two filters placed flush against one another in the sampling apparatus. The measurements performed after the pumping showed that the activity of the second filter was 100 times lower than that of the first filter.During the gas-aerosol examination of the cells holding jackets with fuel assemblies, samples from 163 cells have now been obtained in the process of opening the cells when the concrete plugs, closing the cell openings, were raised. The 137 Cs activity was determined from the results of spectrometric analysis of the filters on a setup with a GC2520 semiconductor detector (USA). The procedure described in [3] was used to convert the area under the total absorption peak of 137 Cs photons into the activity.The results of the measurements performed on the samples from the cells examined showed that the volume activity of 137 Cs varies over a wide range with a several-fold difference -from zero values above background characteristic for a given storag...

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Spent nuclear fuel has been stored in dry-storage units at a shore base of the naval fleet for [35][36][37][38][39][40][41][42][43][44][45] year. The total activity of the spent nuclear fuel is 170 PBq. This article presents data which characterize the state of the fuel (from normal to defective), the radiation conditions, and information on the individual and collective irradiation dose to workers. The results of an inventory check of the cells and jackets which contain fuel assemblies are presented. The corrosion processes are described and ideas for handling the spent fuel at the RT-1 plant of the Mayak Industrial Association, including handling fuel assemblies and jackets in cases, are described.Spent nuclear fuel is an important component of the radiation potential of the objects of the comprehensive salvaging of submarines; it is the determining factor of the nuclear and radiation danger. Neglecting the operational storage of this fuel, the largest amount is found on the shore technical bases in Guba Andreev (total activity 170 PBq) and the town of Gremikha (18 PBk). 137 Cs and 90 Sr make the main contribution to the total activity.One of the final goals of the ecological remediation of these shore bases is the preparation of the spent fuel for shipment to the Mayak Industrial Association for reprocessing. The spent fuel consists of the unreprocessed uranium-zirconium cores of water-moderated water-cooled reactors on icebreakers and the UBe 13 fuel of liquid-metal-cooled reactors. Specialists have studied the reprocessing of such fuel, but the technical-economic investigations have never been completed. The reprocessing volumes are small. They are one-time jobs, but they do require the development of new reprocessing lines and substantial investments.The present article describes methods for handling spent fuel which is in different states, mainly, at the point of prolonged storage on the shore base at Guba Andreev and, in part, in Gremikha. Affiliates No. 1 (Guba Andreev) and No. 2 (Gremikha) of the SevRAO Federal State Unitary Enterprise have been used previously as shore technical bases of the northern fleet for recharging submarine reactors and for receiving spent fuel for temporary storage followed by transfer to a reprocessing facility.