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Development of SC to support Decision Making for Waste Retrieval from Historical RADON-type Facilities Development of SC to support Decision Making for Waste Retrieval from Historical RADON-type Facilities Alexander Smetnik, FSUE VO “Safety” IAEA Headquarters, Vienna, Austria 28 September – 2 October 2015 Technical Meeting of the International Project on Demonstration of the Operational and Long-Term Safety of Predisposal Management Facilities for Radioactive Waste (CRAFT Part II)
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RADON facilities The system of RADON facilities was established the USSR in early sixties of the XX th century collection, transportation, processing and disposal of LILW wastes and disused sealed radioactive sources (DSRS), generated or used in medicine, research institutions, various branches of industry 35 “Radon” facilities in the Soviet Union 16 of them in the Russian Federation 2
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RADON facilities 3 1 - Moscow «Radon» Facility 2 - Leningrad «Radon» Facility 3 - Volgograd «Radon» Facility 4 - Nizhny Novgorod «Radon» Facility 5 - Grozny «Radon» Facility 6 - Irkutsk «Radon» Facility 7 - Kazan «Radon» Facility 8 - Samara «Radon» Facility 9 - Murmansk «Radon» Facility 10 - Novosibirsk «Radon» Facility 11 - Rostov «Radon» Facility 12 - Saratov «Radon» Facility 13 - Sverdlovsk «Radon» Facility 14 - Bashkirskiy «Radon» Facility 15 - Chelyabinsk «Radon» Facility 16 - Khabarovsk «Radon» Facility
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RADON facilities Typical historical repositories are vaults below the ground level with the volume from 200 to 9000 m 3, basement made of concrete plates, walls made of monolithic reinforced concrete or concrete blocks, divided with concrete or wooden walls into cells (sections), the top is covered with reinforced concrete plates, sand and waterproof asphalt layer 4
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RADON facilities 5 depth – 3-6 m width – 5,5 up to 32 m length – 16 up to 100 m.
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Radon facilities 6 Designed and operated as disposal facilities for institutional LILW without intention of the waste retrieval Don’t fit with the safety requirement for near surface disposal (long lived alpha emitters, high active DSRS etc.) Don’t fit with the safety requirements for long term storage (waste package inspection, retrievability etc.)
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Radon facilities 7 Operators of RADON type facilities are obliged to perform safety assessment and upgrade safety Decision making depends not only from the safety issues but from socio-political, technical and economic aspects Most common decisions include: decommissioning of facility upgraded storage facility upgraded disposal facility Measures are often considered: partial or complete RW retrieval and conditioning reconstruction
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Objectives of the RADON-Type Facilities Working Group (CRAFT) 8 to adopt the safety assessment methodology presented in the GSG-3 for the RADON type facility needs; to develop illustrative test case for applying this methodology to RADON type facility using SAFRAN tool; to provide Member States with the supporting information for decision making regarding the future of existing historical RADON type facilities.
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11 Legal & Regulatory Framework - Regulation of RAW Management in Russia Predisposal RAW management. General Safety Requirements GSR, part 5 Predisposal RAW management. General Safety Requirements GSR, part 5 Disposal of radioactive wastes. Principles, criteria and general safety requirements. NP-055-04 Near-surface disposal of radioactive waste. Safety requirements. NP-069-06 Near-surface disposal of radioactive waste. Safety requirements. NP-069-06 Collection, treatment, storage and conditioning of solid RAW. Safety Requirements. NP-020-2000 Collection, treatment, storage and conditioning of solid RAW. Safety Requirements. NP-020-2000 Collection, treatment, storage and conditioning of liquid RAW. Safety Requirements. NP-019-2000 Gaseous RAW management. Safety Requirements. NP-021-2000 Gaseous RAW management. Safety Requirements. NP-021-2000 Disposal of Radioactive Waste. Special Safety Requirement SSR-5 Disposal of Radioactive Waste. Special Safety Requirement SSR-5 Near-surface disposal. Safety Requirements WS-R-1 Safety Fundamentals SF-1 Safety Fundamentals SF-1 Safety of Radioactive Waste Management. General Provisions NP-058-04 Safety of Radioactive Waste Management. General Provisions NP-058-04 RAW WAC for Disposal NP-ХХ-ХХХ RAW WAC for Disposal NP-ХХ-ХХХ
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Decree №1069: Criteria for classifying radioactive waste to special and retrievable RAW Special RAW The collective effective dose for the entire period of the potential danger The risk of potential exposure The collective effective dose for the entire period of the potential danger The risk of potential exposure Retrievable RAW RAW generated: in result of implementation of the state program of armaments and state defense order In result of the use of nuclear weapon for peaceful purposes In result of nuclear and (or) radiation accident in nuclear facility liquid RAW, accumulated in surface water-storage facilities, totaling more than 25000 m 3, commissioned before the entry into force of the Federal Law "On the treatment of waste...", as well as the sediments of the storage reservoirs meet the following criteria: RAW generated: in result of implementation of the state program of armaments and state defense order In result of the use of nuclear weapon for peaceful purposes In result of nuclear and (or) radiation accident in nuclear facility liquid RAW, accumulated in surface water-storage facilities, totaling more than 25000 m 3, commissioned before the entry into force of the Federal Law "On the treatment of waste...", as well as the sediments of the storage reservoirs meet the following criteria: The cost of moving away, processing, conditioning, transportation to disposal facility and disposal of radioactive waste Moving away On site disposal The size of the possible harm to the environment The cost of disposal of radioactive waste, including conversion Site of sRAW to RAW disposal facility, its operation and closing, its safety over the period of the potential danger The size of the possible harm to the environment The cost of disposal of radioactive waste, including conversion Site of sRAW to RAW disposal facility, its operation and closing, its safety over the period of the potential danger RAW storage and its sanitary protection zone located outside the boundaries of settlements, protected areas, coastal protection strips and water protection zones of water bodies, and other security protection zones 1 2 3 Other RAW that hasn't been assigned to special RAW > > On site disposal Moving away Legal & Regulatory Framework
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Context of the safety case 13 GSR Part 5. Predisposal management of radioactive waste. — Vienna: International Atomic Energy Agency, 2009. Requirement 13: Preparation of the safety case and supporting safety assessment The safety case has to be prepared by the operator early in the development of a facility as a basis for the process of regulatory decision making and approval.
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Context of the safety case 14 No. GSG-3. The safety case and safety assessment for the predisposal management of radioactive waste: General safety guide. — Vienna: International Atomic Energy Agency, 2013. The safety case provides the basis for safety decisions with respect to siting and location, design, construction, operation and decommissioning of a facility, including for the justification of changes with a significant impact on safety.
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Context of the safety case 15 The safety case was developed as the project progress and can be used as a basis for decision making relating to selection of the decommissioning option The purpose of safety assessment performed as the illustrative test case is to test initial ideas of the waste retrieval and improvement of technological rules for waste retrieval procedure and/or decision making related to the decommissioning options for historical Radon-type facility
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Context of the safety case 16 The assessment of the future management of retrieved waste is not part of the current safety assessment and safety case. This can be covered by other relevant safety assessments addressing the management steps for such waste, i.e. its clearance, discharge, processing, storage, transport and disposal
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Context of the safety case 17 The endpoint of the safety assessment was the doses for the workers as result of external irradiation and inhalation both for normal and accident scenarios. For treating uncertainties in the safety assessment, cautious assumptions was used, but, in view of the intervention situation, these should be as realistic as possible
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Context of the safety case 18 Timeframe for safety assessment for dose calculation is the sum of time required for all considered technological operations. In terms of possible accidents caused by external events the timeframe cover all the period of waste retrieval operations at the site. Safety assessment calculations were performed using SAFRAN and other tools.
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Description of the facilities, activities and the waste 19 Murmansk solid radioactive waste storage facility is the typical near surface vault constructed from reinforced concrete below the ground level and divided into four cells of 200 m 3 each.
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Description of the facilities, activities and the waste 20
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Description of the facilities, activities and the waste 21
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Description of the facilities, activities and the waste 22 Lake
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Description of the facilities, activities and the waste 23 View of the four RW storage vaults
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Description of the facilities, activities and the waste 24 Waste is not conditioned and in some cases is packed
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Description of the facilities, activities and the waste LegendWasteNumber. Б1 – Б10Cylindrical metal containers10 К1 – К10Rectangular metal containers10 ЯБ1 – ЯБ6Concreted and partially damaged wooden boxes6 ФBox with air filters1 BallsBlocks of gamma-ray sources~ 40 -Unidentified objects6 Vault No1 There are DSRSs in transport containers, few wooden boxes with unknown cemented waste, packages with ion-exchange resins and others. 25
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Description of the facilities, activities and the waste Rectangular metal containers Concreted and partially damaged wooden boxes Blocks of gamma-ray sources BGI-75 Blocks of gamma-ray sources E-1M 26
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Description of the facilities, activities and the waste 27 The inventory consists mostly from 226 Ra, 152 Eu, 137 Cs, 60 Co and 3 H and other radionuclides. The nearest settlement is in the distances of about 10 km from the facility.
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Description of the facilities, activities and the waste 28 Construction of temporary protecting building
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RADONRADON MurmanskMurmansk Gates Walls Storage vaults 29
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Ground water close location is one of the main reason of RW retrieval from RADON facilities 30 The host rocks of Murmansk RF contain groundwater, the level of which varies throughout the year from 2 m to 5 m from the surface.
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Retrieval activities 1 3 2 4 5 31
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The waste retrieval scheme Containers, boxes Radiation control and monitoring Check of holding devices of packages Sling and control lifting Moving of packages Placing into transport container Top cord uncoupling 32
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The radiation survey results Object Position centreNSWE Б1155073020 Б220012070160150 Б37010001205618 Б450060010002000 Б54086005021 Б6192101213 Б760502450 Dose rate, µSv/h 33
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Dose criteria for safety assessment Persons Individual year dose, mSvNote Normative limit Control limit Personnel2010 2-multiple reserve Population10,1Approved quota 34
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Stages and operations of waste retrieval Stages Number of operations №Name 1Retrieval of liquid waste 2Retrieval of containers and packages~35 3Retrieval of gamma radiation blocks40 4Spillage gathering20 5Vault decontamination № SlingerCrane operatorDosimetrist 1 Go down into vaultWaiting of commandsExamination of working place 2 Package SlingHook descentWaste package examination 3 Raise out of vaultRaising package on 100 mm 4 Top cord uncouplingRaising package on level of the canyon overlapping 5 Secondary slingDisplacement into container Operations of stage №2 35
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SAFRAN tool 36 The SAFRAN (Safety Assessment Framework) is a user-friendly software application that incorporates the methodologies developed within the IAEA SADRWMS and CRAFT projects. http://www.safran.facilia.se/safran/show/HomePage
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SAFRAN tool structure blocks Personnel Phase 37
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SAFRAN model detailing 38 Areas of work and retrieval activities
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SAFRAN model detailing 39 Waste retrieval activities for the personnel
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SAFRAN model detailing 40 Initiating events for accidental scenarios
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SAFRAN model detailing 41 Consequences of the considered events can be generalized as: - Drop of waste package; - Loss of power supply. Workers and members of population are collectively addressed as endpoints for the considered accidental events. At the first accidental scenario it is assumed, that accident leads to loss of tightness of waste packages, ingress of Cesium-137 and Strontium-90 radionuclides into the air of the room and their escape outside (taking into account the filtration efficiency of 0.9).
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SAFRAN model detailing 42 Under the second accidental scenario the consequences of ventilation malfunction are considered, due to which the room starts accumulating Radon-222, and occupational personnel exposure increases due to the inhalation component. In case of unavailability of the forced ventilation under permanent ingress of Radon-222 into the room, its concentration value should be controlled by two processes: - air outlet from the room due to natural convection; - radioactive decay (half-life period 3.823 days).
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Calculated exposure dose rates 43
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Conclusions In summary, based on the available evidence and safety analysis, the conclusion of this safety case is that the waste retrieval operations can be safely undertaken and provide a solution to the hazards currently posed by the interim storage of waste at the Murmansk RADON facility. 44
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Conclusions Comparison with safety criteria : The results of the quantitative safety assessment as reflected above are well within the national and international safety criteria for workers and the public. The anticipated dose for workers is 2.9 mSv in comparison to the dose constraint of 10 mSv/annum. The anticipated dose for public is 0.005 mSv in comparison to the dose constraint of 0.1 mSv/annum. 45
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Conclusions Application of SAFRAN tool allows processing of the input data, creation of the demonstrative safety assessment structure and analysis of the alternative options for personnel response actions, occurring in the course of implementation of the concerned activity – under normal operation mode, abnormal operation mode and accidents. 46
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Thank you! 47 FSUE VO “SAFETY”
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