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ESS waste m anagement : Development of the appropriate strategy EDMS 1254736 D. ENE On behalf of WP#11. Why waste management plan for ESS?.
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ESS waste management: Development of the appropriate strategy EDMS 1254736 D. ENE On behalf of WP#11
Why waste management plan for ESS? Waste refers to materials that are not prime products (that is, products produced for the market) for which the generator has no further use in terms of his/her own purposes of production, transformation or consumption, and of which he/she wants to dispose Waste managementis the collection, transport, processing or disposal, managing and monitoring of waste materials.
Radioactive waste • waste that contain radioactive material • by-products of applications, such as research and medicine • hazardous to most forms of life and the environment, • regulated by government agencies in order to protect human health and the environment • Radioactivity diminishes over time, so waste is typically isolated and stored for a period of time until it no longer poses a hazard • Low-level waste with low levels of radioactivity per mass or volume may need to be stored for only hours or days • High & intermediate -level wastes must be stored for a year or more.
NOW FUTURE • Basic types of waste: • Solid • Liquid • Gaseous • -effluent • -operational • -decommissioning • WASTE • MANAGEMENT
Waste management concepts • The waste hierarchy is a classification of waste management t options in order of their environmental impact: • reduction, • reuse, • recycling • recovery. • In Europe the waste hierarchy has 5 steps: • prevention; • preparing for re-use; • recycling; • other recovery, e.g. energy recovery; • disposal waste minimization strategies
Under Swedish law, ESS as the holder of a licence to operate a radiation facility is primarily responsible for the safe handling and disposal of radioactive waste, as well as decommissioning and dismantling of the facility.
Planning process and public consultation • there will be a great many • potential integrated • 'options' that will allow • wastes to be managed effectively. • collection employed, • specific materials recovered, • recycling • dominant disposal route • broad location of waste • management sites. • Each integrated waste management option will have a range of impacts on the • economic, environmental and social objectives that comprise the concept of • sustainable development. • preferred option : BAT an integrated approach to waste management
ESS BAT and optimization : Tritium management • Assessment criteria Criteria: • T discharge to air • T discharge to water • Radioactive solid waste generated • Cost • Timescale for implementation • Operator hazard • Security implications • Social and economical considerations Options: • Nothing =>Reference • Capture T gas in bubbler traps • Capture T gas in molecular sieves • Evaporation • Cementation • Others Analysis of options
Status • Requirements • Waste radiological characterisation • Waste management | planning & logistics • Waste streams and emissions during operation • Environmental impact analyses: routine operation & accidents • Decommissioning
Waste characterisation • Inventory => DB to SKB for Source Term evaluation, Waste classification, Transportation • Alpha component • Gases production | evolution => design, waste rate, ST • Decay times => logistics , transportation • Heat load => logistics, transportation • Gamma dose rate model => handling, transportation • Model validation=> accuracy • Other components
ESS waste There is no legally defined waste classification system in Sweden for radioactive waste. There are however established waste acceptance criteria for different disposal route of radioactive waste. ESS waste are peculiar within Swedish waste system. Lots of radioisotopes of ESS waste are not included in SKB database and special treatment/conditioning methods should be developed for components of ESS facility. Swedish waste is mainly coming from NPPs. In this respect the new waste streams that should be established in agreement with Studsvik and SKB should be licensed by SSM. Designing and building the SFL repository that will be likely the host of many of ESS waste will require a safety analysis including ESS waste streams and special Waste Acceptance Criteria (WAC) for our waste. It is a long process involving ESS. It started since 2012 and should continue until SSM will approve it.
Waste classification using clearance concept (IAEA Safety Guide SS No.111-G1 (1994)) 3. Clearance indexes determination CI= (IAEA TECDOC 855 recommendations) Ai= specific activity of each component in the material; Li= Clearance limit (Bq/g) derived to meet individual dose criterion of 10mSv/y -Litaken fromIAEA Safety Guide Report RS-G-1.7 (2004) -Licalculated using: Eg, Eb from FENDL D.2.0; ALIing, inh from ICRP72 CI = Ai= specific activity of each component in the material; CLi= Clearance level (Bq g-1) derived to meet individual dose criterion of 10 mSv y-1 • HLW = High Level Wastes, Heat generating • LILW =Low and Intermediate Level Wastes: • 2.1 LL -LILW = Long Lived - LILW • 2.2 SL -LILW = Short Lived – LILW • EW = Exempt Wastes • CI < 1 =>EW; • CI > 1 : • CI of nuclides with T1/2> 30 years <1 => SL-LILW • CI of nuclides with T1/2> 30 years >1 & • Long lived alpha emitters: > 400 Bq g-1 average; • > 4000 Bq g-1 individual package • 3. & Generated heat (>2 kW m-3) => HLW ESS CI library achieved and used for TMRA items LL-LILW Free release of materials, facilities, buildings and land for activities involving ionizing radiation In force in Sweden since January 2011 SSMFS:2011:2
Shipping of the W target waste Side: 22 cm Non optimized End: 27 cm contact: 2mSv/h Material: Fe 1 m air: 0.1mSv/h mass: <35 tones =>Feasible W SS Sv/h Gamma source: 5 years decay Radial profile Axial profile Sv/h Sv/h
Waste management:planning & logistics • Management of radioactivity in the facility Logistics for Target Station high activated items: hot cell storage & decay • Waste segregation, collection & sorting (types, classes) • Minimization of waste : decay storage, free release, recycling, preconditioning <if> Free release measurements Interim storage facility & preconditioning Quality assurance: waste type description } Swedish system • Waste streams & treatment-conditioning protocol • Transport: Package Type, B(U) & Swedish standard containers • Disposal routes: existing and planned Swedish disposal facilities (SFR, SFL) • Logistical plan • Waste management plan
Operation & maintenance: waste streams • Main waste components: high activated components of Target Station • Radioactive waste generated in fluid cooling systems: resins/trapping/filters/dust/waste water • Difficult to predict waste: • dry: scrap metal from filters & others, magnets, vacuum pumps, instrumentation, choppers, activated samples, etc • organic liquids (activated oil)
Operation & maintenance: waste streams The diffusion half-life of representative elements within the tungsten target and the emanation half-life of volatile elements in the dust Operation waste streams arising from the purification and ventilation systems
Operation & maintenance: emissions • Handling of Tritium • Source Term for atmospheric releases: • On line emissions (linac); • Processing emissions (hot cell, HTO solidification <if>, others) • Source Term for contaminant migration via groundwater • Source term for discharge in the sewage system outcome of labs (tbd) • Monitoring program outside • the facility
Operation & maintenance: Source Term Source term for airborne release from online operations Source term for airborne release from processing operations
Environmental impact analyses: routine operation : airborne • Dose calculation methodologies • (ARGOS system & ECOSYS (food chain dose model) • ESS Source Term break-down • Available site specific data • Preliminary definition of the critical group • HTO => a special modeling approach (water entering the body of an exposed person will have the same tritium concentration) • Total dose estimate: • Inhalation • Ingestion • External: • contaminated plume during its passage. • deposition of airborne contaminants on surfaces. • deposition of airborne contaminants on humans. • H*(10) = 9 mSv/y (r=0.5/day)=> C-11, N-13 and O-15 =>external exposure • 17 mSv/y (r=1/day)
Routine operation r =1/day => H*(10) breakdown: r =0.5/day => H*(10) = 9 mSv/y
Environmental impact analyses: routine operation : groundwater • TRACE(velocity field)/PARTRACE(transport of solutes) code used radionuclide-transport calculation • Parameters: • homogenous soil with a bulk density of 2.0 g cm-3 • hydraulic gradient set to 0.0025 • hydraulic conductivity Ks = 1E-6 m s-1 • sorption & Decay accounted • Assumptions: • continuous plane contamination source of 300 m length and 6 m width. • BSA at 250 m downstream the accelerator in direction of the groundwater flow • H*(10) = 4E-5 mSv/y • Tritium, needs about 900 years for reaching the site boundary. • During the lifetime of the facility of 80 y • (40 y operation plus 40 years until ‘green field’ • is re-established) : • No relevant contamination can occur • outside of the site boundary. Travel times of the investigated radionuclides
Environmental impact analyses: accidents • Source Term for DBA & BDBA =>ESS-0000056/1: • It is necessary to perform a sensitivity study where the specific release factors for volatiles • (RFV) and aerosols (RFA) are varied. • Assumption : the noble gases and tritium will be released to the atmosphere, volatiles and aerosols will vary depending on the exact scenario • 2 volatiles release fractions were investigated: 0.001 and 0.5 % • Ranking of the main isotopes by their importance with respect to dose: H3, Is, Xe121 • Total dose estimates: • 0.001% => H-3(ingestion) • H*(10) = 0.7 mSv < 50mSv (GSO) • 0.5% => I-125(ingestion) • H*(10) = 20 mSv(plant growth season) • 0.4 mSv(other seasons)
Accidents RF of 0.001% Total dose estimated from DBA scenario amounts to 0.7 mSv RF of 0.05% Total dose estimated from DBA scenario amounts to 20 mSv
Decommissioning (2065-70) • Analysis of the decommissioning strategies, factors and constraints • Immediate dismantling as ESS decommissioning reference strategy: • most important factor is that the unique accumulated experience of the operating staff during decommissioning. • ESS's goal will be to return the site to green field status. • Preliminary decommissioning plan: • • Licensing conditions • • Staffing and training • • Organization and administrative control • • Cost estimation • • Waste management • • Emergency management • • Radiation and physical protection • • On and off site monitoring • • Quality assurance • Engineering design recommendations: • Decommissioning plans • Site factors • Facilities and system design • Structural design • Operational design • Materials design • Waste management