Handling High-Level Radwaste During Decommissioning of the MR and RFT Research Reactors

Volkov, V. L.; Ivanov, O. P.; Kolyadin, V.I.; Lemus, A. V.; Muzrukova, V. D.; Павленко, В. И.; Potapov, V. N.; Semenov, S. G.; Smirnov, Sergey; Stepanov, V. E.; Fadin, S. Yu.; Chesnokov, A. V.; Shisha, A. D.

doi:10.1007/s10512-014-9791-6

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Section: Methods and Equipment For Dismantling Work And Handling Radwmentioning

confidence: 99%

“…The aluminum end piece, whose activity is much lower, was removed fi rst. Depending on its activity a block was fragmented and packed in accordance with the technology for handling high-level wastes [7]. The transport containers used for shipment to a long-term storage facility were placed in a consolidation center used for temporary storage.…”

Section: Methods and Equipment For Dismantling Work And Handling Radwmentioning

confidence: 99%

“…At the preparatory stage, the dismantled equipment was examined with a gamma-locator and gamma-viewer in order to discover the intensely radiating surfaces of the equipment, after which the optimal ways to perform the work was determined. On the basis of the data obtained, the dismantled equipment and remote-controlled machines were installed in the room and the sequence of operations was determined [7,8]. The main dose-forming nuclides were 137 Cs and 60 Co. A wide collection of machines, manufactured by the Brokk Co. (ranging from Brokk-90 to Brokk-400, six in all) were put into operation, which provided an effective power-to-weight ratio and made it possible to perform all required operations using different tools without workers being present in the high-radiation zones.…”

mentioning

confidence: 99%

“…The activity of the blocks extracted from the core was in the range 7-30 GBq and the equivalent dose rate at 1 m from the center of the block was 5-20 mSv/h. The activity is distributed nonuniformly along the blocks with maximum radiation on the central zones of the block [7,8].The low-and medium-level wastes were packed into concrete and metal containers and shipped to the Radon association for long-term storage. Some graphite and beryllium blocks were packed as high-level wastes in hermetic cases and placed in temporary storage for high-level wastes.…”

mentioning

confidence: 99%

“…7). In order to reduce the volume of the medium-and high-level wastes, after extraction from the reactor pool the beryllium blocks were fragmented in the same sequence as in the work done in the cool-down pool [7]. The aluminum end piece, whose activity is much lower, was removed fi rst.…”

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Dismantling of MR-Reactor IN-Vessel Setups

et al. 2015

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The results of dismantling performed on the in-vessel structures of the MR research reactor at National Research Center Kurchatov Institute are presented. Remote-controlled mechanisms and remote methods of diagnostics of the radiation conditions were used to perform the operations. These methods and technologies made it possible to provide radiation protection for the staff performing radiation-hazardous work and meet the dose-load requirements established in the regulatory documents. The results of dose-rate measurements in the work zones and the irradiation doses to personnel performing this type of work are presented.The MR research reactor at the National Research Center Kurchatov Institute is being decommissioned. During its period of operation the reactor was equipped with nine loop facilities for conducting a series of tests and investigations of different types of fuel elements, fuel, and structural materials. These facilities made it possible to study the thermophysical, hydrodynamic, and strength characteristics of elements of the core and the primary equipment of power reactor setups intended for different purposes under conditions as close as possible to natural. Its power together with the loop facilities reached 50 MW [1,2].The equipment of the loop facilities was placed in the basement rooms of the MR reactor building and was highly contaminated -the equivalent dose rate in individual rooms reached 20 mSv/h. In 2013-2014, the equipment in all nine loop facilities was disassembled and about 47 rooms were emptied of equipment [3]. The disassembly of the equipment made it possible to reduce the equivalent dose rate in rooms from 5-20 to 0.01-0.03 mSv/h. The in-vessel facilities of MR were disassembled in 2014.Aside from this, high-activity elements of the reactor and beryllium blocks were removed from the cool-down pool. The beryllium blocks, being structural elements of the core, and the graphite blocks, playing the role of the refl ector of the reactor, were also extracted, packed in cases or containers and removed, one part to a consolidation center and another to the high-level waste repository and subsequent shipments into long-term storage.More than 800 tons of MR equipment were dismantled in 2011-2014. Of this, more than 600 tons were radioactive wastes with total activity ~20 TBq. About 160 channels of the loop facilities and ~300 beryllium and graphite blocks with total 60 Co and 137 Cs activity ~55 TBq were removed from the reactor pool and fragmented. The high-level parts of the channels and blocks were packed in cases and placed in storage for cool-down; the medium-and low-level wastes were loaded into NZK-150-1.5P and KRAD containers and place in long-term storage at the Scientifi c-Industrial Association Radon. About 3000 m 3 of solid and 5000 m 3 liquid radwastes were removed from the territory; the total activity of the removed wastes reached 80 TBq.Remote controlled machines (Brokk Co., Sweden) were used to dismantle the equipment and handle the wastes. The intensely radiating parts w...

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Section: Methods and Equipment For Dismantling Work And Handling Radwmentioning

confidence: 99%

Section: Methods and Equipment For Dismantling Work And Handling Radwmentioning

confidence: 99%

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confidence: 99%

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confidence: 99%

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confidence: 99%

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