Strategic Guidance on the Management of LLW and ILW / LLW ...

National Waste Programme<strong>Strategic</strong> <strong>Guidance</strong> on theManagement of LLW andILW / LLW Cross BoundaryPond FurnitureNWP/REP/011 – Issue 2.1 – Jan 2013A company owned by UK Nuclear Waste Management LtdOld Shore Road, Drigg, Holmrook,Cumbria, United Kingdom, CA19 1XHCompany Registration No. 05608448NOT PROTECTIVELY MARKED

NWP/REP/011Issue 2.1 – Jan 2013Page 2 of 58National Programme Office<strong>Strategic</strong> <strong>Guidance</strong> on theManagement of LLW and ILW/ LLW Cross-Boundary PondFurnitureDocument ManagementOriginator:Checker:NameHelen CassidyHannah KozichRoleNational Programme ImplementationManagerNational Programme ImplementationManagerApprover: David Rossiter Head of National ProgrammeA company owned by UK Nuclear Waste Management LtdA company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 3 of 58Executive SummaryPond furniture, defined as the metallic architecture used for the storage and handling of irradiatedfuel in cooling ponds which has been or is being stored under water, is a ubiquitous waste withinthe Nuclear Decommissioning Authority (NDA) estate. Decommissioning of fuel cooling ponds willgenerate (retrieve) a significant volume of metallic waste. Despite the significance of thiswastestream, historically there have been limited efforts to analyse detailed information about thecharacteristics of this waste and the approaches site licence companies (SLCs) are using, orintend to use, for management of this waste. The objective of this strategic guidance document isto provide a cross-NDA estate compilation of this data on inventory and management approachesas a vehicle to support the transfer of knowledge, best practice, lessons learned and innovationacross the NDA estate.An extraction, review and refresh of data from the United Kingdom Radioactive Waste Inventory(UKRWI) 2010 estimates that the total volume of pond furniture classifiable as low level waste(LLW) or intermediate level / low level (ILW / LLW) cross boundary waste in the NDA estate is14315m 3 . This waste inventory is predominantly located at the Sellafield site (some 95% of thetotal volume) and consists mainly of stainless steel. The volume is dominated by LLW, albeit thatmuch is expected to be at the upper end of the LLW category. In the near term, it is expected thatthe majority of the waste will arise from decommissioning of the fuel ponds at Research SitesRestoration Ltd (RSRL) Harwell site, the Magnox Ltd. sites (Bradwell, Chapelcross, Dungeness A,Oldbury and Sizewell A) and the legacy pond facilities at Sellafield (First Generation MagnoxStorage Pond (FGMSP) and Pile Fuel Storage Pond (PFSP)).Historically, NDA estate SLCs have relied on disposal, either directly to the Low Level WasteRepository (LLWR) or else interim storage pending disposal to the Geological Disposal Facility(GDF), but there is increasing utilisation of decontamination and diversion to alternative wasteroutes such as metal melting.Significant efforts have been expended by SLCs (particularly Magnox Ltd.) into ongoing researchand development (R&D) programmes to identify and implement new approaches for managementof pond furniture. Examples of techniques trialled through these R&D programmes include foamdecontamination, acid decontamination, Decontamination For Decommissioning (DFD),Decontamination For Decommissioning Electrochemical Ion Exchange (DFDX), metal milling andnitrocision.Through review of the routinely used processes for management of pond furniture and widerdiscussions with the SLCs, a generic decision-making process to support waste managementoptioneering has been developed. This illustrates the relationship between waste managementdecisions and outcomes (using the waste management hierarchy), demonstrating howcombinations of decisions can be used to drive to waste management solutions of leastenvironmental detriment. This is intended to inform and support the detailed optioneeringprocesses used by the SLCs.A range of issues and opportunities have been identified and reviewed. Management of theseissues, and exploitation of the opportunities, provides a mechanism to improve and optimise theefficacy of waste management practices for pond furniture within the NDA estate.A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 4 of 58Acronyms and AbbreviationsTermAGRALARPBATBPEOCNCDFDDFDXEARWGEPRFGMSPGDFHHISOILWILW/LLWLLWLLWRLWRMEBMRFNDANOxPFSPR&DRSA93RSRLRWMDSLCUHPUKUKRWIUSAWACDefinitionAdvanced Gas-Cooled ReactorAs Low As Reasonably PracticableBest Available TechniqueBest Practicable Environmental OptionComputer Numeric ControlDecontamination for Decommissioning ProcessDecontamination for Decommissioning, Electrochemical Ion Exchange ProcessEnvironment Agencies Requirements Working GroupEnvironmental Permitting Regulations (England and Wales) 2010 (as amended)First Generation Magnox Storage Pond (Sellafield Ltd.)Geological Disposal FacilityHalf-height ISO containerIntermediate Level WasteIntermediate Level Waste / Low Level Waste Cross-Borderline WasteLow Level WasteLow Level Waste RepositoryLight Water ReactorMulti-Element BottleMetal Recycling FacilityNuclear Decommissioning AuthorityNitrogen OxidesPile Fuel Storage Pond (Sellafield Ltd.)Research and DevelopmentRadioactive Substances Act (Scotland) 1993 [as amended]Research Sites Restoration Ltd.Radioactive Waste Management DirectorateSite Licence CompanyUltra High PressureUnited KingdomUnited Kingdom Radioactive Waste InventoryUnited States of AmericaWaste Acceptance CriteriaA company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 5 of 58DefinitionsTermActivated itemLLW / ILW cross boundary wastePond furnitureSurface contaminated itemVolumetrically contaminated itemDefinitionA solid object which has become radiologically contaminatedby activation products resulting from neutron radiation.Those wastes with radiological characteristics either side ofthe LLW radiological classification boundary that couldpracticably be managed either as LLW or else as ILW.For the purposes of this document, this is defined as themetallic architecture used for, and associated with, thestorage and handling of irradiated fuel in cooling pondswhich has been or is currently stored under water, and whichis classified as either low level waste (LLW) or else isintermediate level waste (ILW) where there is believed to bea practicable chance of using treatment or conditioning torender it LLW.A solid object which is not in itself radioactive but which hasfixed and / or loose radioactive contamination distributed onany of its surfaces (including internal surfaces).A solid object for which radioactive contamination isdistributed, to some degree, throughout the volume of theobject and not just contained on the surfaces of the object.A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 6 of 58Contents1. Introduction.......................................................................................................................... 82. Purpose ................................................................................................................................ 93. Background........................................................................................................................ 113.1. What is pond furniture? ......................................................................................... 113.2. How has radiologically contaminated pond furniture arisen? ............................ 113.3. Why is management of pond furniture an issue? ................................................ 134. Inventory ............................................................................................................................ 144.1. Assumptions........................................................................................................... 144.2. Volumes .................................................................................................................. 154.3. Waste types ............................................................................................................ 154.4. Radiological Classification.................................................................................... 174.5. Schedule for waste generation.............................................................................. 175. Waste Management Strategies ......................................................................................... 195.1. NDA Estate Waste Management Strategies.......................................................... 195.1.1. Magnox Ltd. ............................................................................................................. 195.1.2. Sellafield Ltd............................................................................................................. 205.1.3. Research Sites Restoration Ltd. ............................................................................... 205.2. Technology summaries - waste management approaches in routine use......... 215.2.1. Size Reduction ......................................................................................................... 225.2.2. Surface Washing ...................................................................................................... 235.2.3. Surface Wiping......................................................................................................... 255.2.4. Mechanical Surface Decontamination (Ultra-High Pressure Water Jetting) .............. 265.2.5. Mechanical Surface Decontamination (Shot-Blasting) .............................................. 285.2.6. Mechanical Surface Decontamination (Spongejet) ................................................... 305.2.7. Chemical Decontamination (strong mineral acids).................................................... 325.2.8. Metal Melting............................................................................................................ 345.2.9. Optimised Disposal to Low Level Waste Repository (LLWR).................................... 385.2.10. Direct Disposal to Low Level Waste Repository (LLWR)........................................... 405.2.11. Disposal to Geological Disposal Facility (GDF)......................................................... 415.3. Technology summaries - pond furniture management R&D............................... 425.4. Other pond furniture waste management approaches ........................................ 426. Waste Management Decision Making Logic .................................................................... 507. Issues and Opportunities.................................................................................................. 548. Conclusions ....................................................................................................................... 559. References ......................................................................................................................... 57A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 7 of 58Figures1. Benefits matrix for pond furniture strategic guidance…………………………………… 92. Key in-situ pond mechanisms for contamination of pond furniture…………………... 123. Total volume of pond furniture waste (m 3 ) within NDA estate………………………….. 154. Proportion of pond furniture volume (m 3 ) by type for each relevant site within theNDA estate……………………………………………………………………………………… 165. Breakdown of pond furniture volume (m 3 ) by radiological classification……………. 176. Schedule of pond furniture waste retrievals within NDA estate 2012-2100………….. 187. MEB at Studsvik UK Metal Recycling Facility pending size reduction……………….. 368. Metal melt and pour process at Bear Creek……………………………………………….. 379. Cast recycled metal shield blocks at Bear Creek…………………………………………. 3710. Waste processing rig at Inutec………………………………………………………………. 3911. ISO container being filled with pucks of supercompacted waste at Inutec………… 3912. Summary of historic and current R&D into pond furniture management……………. 4313. Wylfa heat exchanger plate prior to application of DFD process……………………… 4914. Wylfa heat exchanger plate post application of DFD process………………………….. 4915. Waste management thought logic diagram for management of pondfurniture…………………………………………………………………………………………… 5116. Waste management hierarchy………………………………………………………………... 52Case StudiesA. UHP water jetting of pond skips at Bradwell……………………………………………….. 27B. Spongejet decontamination of pond furniture at Hunterston A………………………… 31C. Nitric acid fuel skip decontamination at Hunterston A…………………………………… 33D. Metal melting of Sellafield Ltd. MEBs………………………………………………………… 36E. Metal melting of ferrous fuel skips from Hinkley Point A………………………………… 37F. Optimised disposal of pond skips from Bradwell by Energy Solutions and Inutec…. 39G. DFD decontamination of Wylfa heat exchanger plates…………………………………… 49A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 8 of 581. IntroductionPond furniture – the metallic architecture used for the wet storage of irradiated fuel – is aubiquitous wasteform across the Nuclear Decommissioning Authority (NDA) estate. It is acomplex wasteform from a waste management perspective due to its variability in type,physical geometry and radiological characteristics.Despite its ubiquity and its importance as a source of a significant volume of metallicwaste, pond furniture has not previously been considered in a national strategic context;for example, neither the National LLW Strategy [Ref. 1] or the <strong>Strategic</strong> Best PracticableEnvironmental Options (BPEO) assessment for metallic waste [Ref. 2, 3] specificallyreference pond furniture, instead focussing on radioactive metals as a whole. It isacknowledged that significant work has been undertaken by SLCs and the supply chain informulating, trialling and implementing waste management approaches for thiswastestream; however, the outputs of this work has not typically been widelydisseminated beyond individual organisations. This historical lack of knowledge transferand learning from experience has contributed to duplication of effort and, in some cases,implementation of non-optimised waste management strategies.This report intends to provide the first cross-NDA estate compilation of inventory data andwaste management approaches specifically for pond furniture, with the intent of providingan effective vehicle for the transfer of knowledge – particularly good practice, lessonslearned and innovation – across the NDA estate. It should be noted that this strategicguidance is not intended to supplant any existing, or developing, SLC or specific sitestrategies for the management of LLW, ILW / LLW cross-boundary wastes, ILW or pondfurniture; but rather seeks to augment any such local strategies and to provide anadditional tool to support waste practitioners in informed and underpinned decisionmaking.This document has been developed in collaboration with the NDA-estate SLCs and thesupply chain. Inventory information presented in this document is extracted from UKRWI2010, with additional validation of the data by the SLCs. The compilation of wastemanagement approaches has been derived using information submitted by SLCs and thesupply chain, supported where appropriate by literature review. Similarly, identification ofcross-estate issues and opportunities relating to the management of pond furniture hasbeen derived based on information provided by the SLCs.It is intended that this compilation shall be periodically reviewed to take account ofchanges in waste inventory, strategy, management approaches and technology; so as toensure that this document remains current and fit-for-purpose.A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 9 of 582. PurposeThis strategic guidance document intends to serve three main purposes:• To provide a UK-wide inventory of pond furniture detailing the types, volumes andknown or assumed radiological classifications of the waste. This will allow foridentification of synergies and opportunities for consolidated waste treatment acrossthe NDA estate, as well as providing the supply chain with better clarity on the natureof the predicted arisings of pond furniture to inform future service provision or elseimprovements to current service provision.• To provide a compilation of information on current and credible near-term futureapproaches being employed within the NDA estate for management of pond furniture.This is to enable sharing of information, best practice and lessons learned; and toenable the identification of synergies and opportunities between sites. This isaugmented by the inclusion of case studies on relevant wastes, where particulartechniques have been employed by SLCs for management of pond furniture wastes.• To provide decision making logic for waste practitioners based on the current wastemanagement practices, to complement existing waste management strategies and tosupport waste management decision making / optioneering.The intended benefits of the use of this strategic guidance document for waste producers,service providers, LLWR Ltd. and other stakeholders are summarised in Figure 1.Figure 1 – Benefits matrix for pond furniture strategic guidanceWho receives benefit?BenefitContribute to avoidance of the need for a secondUK LLWR through optimized waste managementpractices.More cost-effective waste management of pondfurniture due to knowledge transfer of bestpractice, lessons learned and innovations acrossNDA estate.Maximisation of opportunities for new orimproved service provision from management ofpond furniture through improved inventory andschedule data.Waste producerLLWR Ltd.Service ProvidersRegulatorsOther Stakeholderš ̌ ̌ ̌ ̌̌ ̌ ̌ ̌ ̌̌ ̌ ̌A company owned by UK Nuclear Waste Management LtdIt should be noted that whilst this document specifies a range of potential wastemanagement options for pond furniture (either in routine use or else in research andNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 10 of 58development), the purpose of this document is not to identify preferred options or to rankoptions but to facilitate the sharing of information relating to the range of options available.The selection of specific waste management options is a matter for the waste owner andshould encompass a wide range of criteria (such as, but not limited to, cost, health andsafety, ALARP and dose uptake, environmental impacts, trans-frontier shipment issuesetc.).A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 11 of 583. Background3.1. What is pond furniture?For the purposes of this strategic guidance document, pond furniture is defined as:Metallic architecture used for, and associated with, the storage and handling ofirradiated fuel in cooling ponds which has been or is currently stored under water, andwhich is classified as either low level waste (LLW) or else is intermediate level waste(ILW) where there is believed to be a practicable chance of using treatment orconditioning to render it LLW.This includes metallic waste such as (but is not limited to) storage racks, skips, frames,containers and element bottles. Transport flasks are specifically excluded from thisdefinition.3.2. How has radiologically contaminated pond furniture arisen?Pond furniture has arisen as a specific category of waste owing to the wet storage ofspent nuclear fuel. Spent nuclear fuel removed from nuclear reactors requires a period ofinterim storage pending reprocessing or disposal to allow for physical cooling of the spentfuel and a period of radioactive decay. This interim storage of spent fuel can beundertaken in wet or dry conditions. Reactor stores for spent fuel are - or were, prior todeplanting - predominantly water filled as water is an effective radiation shield atappropriate depths, is a good heat transfer medium, allows for ready manipulation ofspent fuel and allows for ready visibility of pond contents [Ref. 4]. Similarly, on transfer toSellafield Ltd. for reprocessing, spent fuel is also stored in ponds to allow for furtherradioactive decay and cooling, as well as to enable buffer storage to enable arisings to beappropriately grouped into campaigns for treatment and to provide storage capacity in theevent of the plant being unavailable. A range of metallic architecture is required to enablethis wet storage of spent fuel such as racks, skips, frames, containers, and trolleys.Pond furniture can become contaminated through a variety of mechanisms [Ref. 4, 5] asillustrated in Figure 2:• Neutron emission from spent fuel can cause activation of pond furniture, producingradioactive isotopes such as Cobalt-60, Iron-55, Manganese-54 and Nickel-63. This isespecially noticeable for certain wastes (e.g. fuel casks and canisters) with longcampaign histories and located for storage in close proximity to sources of highneutron emission.• During reactor operation, fuel cladding becomes activated by neutrons and theexternal surface of the cladding can, by adhesion, accumulate a layer of activatedcorrosion products from the primary cooling system. This crud can be dispersed fromthe cladding and become a source of loose contamination within the ponds.• Radionuclides (fission products) can leak out of fuel rods into the pond water in theevent of a pinhole leak or defect in fuel cladding. In addition, activation of trampuranium on fuel cladding may lead to the release of fission products to coolant water.These mechanisms can spread contamination to other items within the pond.• For pond furniture waste within the legacy pond facilities at the Sellafield site (FGMSPand PFSP), further contamination has occurred by contact between pond furnitureA company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 12 of 58items and corroded nuclear fuel and sludge resulting from the debris of fuel / metalliccorrosion, wind blown debris and bio-organic wastes [Ref. 6].Figure 2 – Key in-situ pond mechanisms for contamination of pond furnitureClad fuel rodPond FurnitureClad fuel rodPond FurnitureCrud adhering to fuelcladding surfacenCrud suspendedin pond water(a) Neutron activation (close proximity)Crud adhered to pondfurniture surface(b) Contamination due to fuel cladding crud depositionClad fuel rodPinhole leak infuel rod claddingPond FurnitureClad fuel rodPond FurnitureR-XXR-XXR-XXR-XXR-XXnR-XXR-XXR-XXActivation ofRadionuclidestramp uraniumdissolved inRadionuclideon claddingpond waterdeposited onto pondfurniture(c) Contamination due to radionuclide depositionSludge from corroded fuel,corroded metal and debris.(d) Contamination due to contaminated sludgesThe extent of contamination is dependent on the physical / chemical form of the pondfurniture, the degree of protective surface coatings, the concentration of radioactiveisotopes present in the pond water and the contact time between the pond furniture andthe contamination source in the pond. Long contact times can result in the migration ordiffusion of contamination into the surface metal [Ref. 5].A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 13 of 583.3. Why is management of pond furniture an issue?The retrieval and management of pond furniture is an integral part of the decommissioningprocess for fuel storage ponds. It poses a particular challenge to the decommissioningand waste management communities owing to the nature of the waste, the (typically) highdose environments where the waste is stored and tensions between waste managementrequirements and the cost / schedule of the wider decommissioning programme. Pondfurniture is a complex wastestream with significant variability in chemical, physical andradiochemical characteristics as a consequence of the differences in historical usage, thetypes of surface coating (if any), historical / current storage regime and the multiplemechanisms for contamination as outlined in section 3.2. This variability in thecharacteristics and waste type of pond furniture can vary significantly within populations ina single pond, between sites within a single SLC and between SLCs. This means thatthere is not a “one size fits all” approach for waste management and that a combination ofwaste management strategies is required to manage the variability in the waste (adding tothe complexity, cost and timescales for the activity).Implementation of effective waste management strategies for this waste is thus importantfor ensuring that waste is retrieved and managed in a cost effective and timely manner soas to enable wider decommissioning programmes to proceed as planned, whilst enablingthe waste to be managed so as to ensure that detriment (to the environment, nuclearprovision and any waste disposal facilities) is minimised as far as practicable.A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 14 of 584. InventoryWaste inventory information for the UK nuclear industry is periodically collated centrally tomeet specific international reporting requirements [Ref. 7], and currently a UK RadioactiveWaste Inventory (UKRWI) is generated every three years to meet these requirements. Areview of the data pertaining to pond furniture, with refresh of the data by SLCs asappropriate, has been undertaken to develop a discrete inventory of pond furniture wastefor the NDA estate. The inventory is described in terms of volumes, waste types,radiological classifications and timescales for waste generation in the sections below.4.1. AssumptionsA number of specific assumptions have been used in the generation of this wasteinventory:• The primary data set is the UKRWI 2010. The specific assumptions used for thegeneration of the UKRWI 2010 apply to this inventory [Ref. 8].• The data reported is that which is directly attributable as pond furniture within UKRWI2010. It is known that there is a volume of other miscellaneous pond furniture wastethat will be generated by decommissioning of the fuel storage ponds at SLCs(particularly Magnox Ltd. and Sellafield Ltd.) but this is reported within UKRWI 2010under different waste categories and is difficult to attribute as pond furniture waste. Ascurrently the volume and categorisation of this waste cannot be quantified, this wasteis excluded from this inventory.• The information submission from Sellafield Ltd. specifically excludes Multi-ElementBottles (MEBs), a waste type which is exclusive to the Sellafield site and one for whichthere is a defined and ongoing waste management programme.• Data pertaining to any pond furniture in the Sellafield Wet Inlet Facility is specificallyexcluded owing to commercial and security sensitivities.• Only five Magnox Ltd. sites have been identified as possessing an inventory of pondfurniture under the definition of this report (Bradwell, Chapelcross, Oldbury,Dungeness A and Sizewell A). The other Magnox Ltd. facilities do not have wetstorage facilities, or are in a more advanced stage in their decommissioningprogrammes so pond furniture waste has already been managed, or else haveassigned their small volume inventories of pond furniture to other wastestreams (e.g.Hinkley Point and Hunterston).• It is assumed by Magnox Ltd. that all fuel skips are classifiable as ILW (based onhistory and provenance) and characterisation / re-classification of the waste will not beundertaken until retrieval. For this strategic guidance, the pond furniture waste forMagnox Ltd. is assumed to be ILW / LLW cross-boundary waste.• Data for Dounreay is specifically excluded from this study as the Dounreay pondfurniture waste is expected to be structural waste integral to the pond structure andfuel containers specific to the Dounreay site. Dounreay Ltd. does not classify thiswaste as pond furniture under the definition of this strategic guidance.• Data relating to the timescales for waste generation and decommissioningprogrammes in section 4.5 is based on publicly available information published in SLCPlans [Ref. 9, 11, 12] and the UKRWI. It should be noted that schedules, particularlyfor decommissioning activities, are dependent on a range of factors including fundingavailability, corporate priorities and regulatory requirements. Consequently, thesetimescales are subject to change and are provided for indicative purposes only.A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 15 of 584.2. VolumesThe total arisings of pond furniture waste within the NDA estate between 2012 and 2100are shown in Figure 3. A total volume of around 14315 m 3 of pond furniture is expected tobe generated during this period, which in the national context equates to 2% of the totalmetallic waste volume declared in the UKRWI 2010 [Ref. 8] or 3% of the total LLWRcapacity. The most significant volume of pond furniture waste is held by Sellafield Ltd. onthe Sellafield site, accounting for approximately 95% of the total volume. The Bradwell site(operated by Magnox Ltd.) has the smallest volume of waste, approximately 0.04% of thetotal, which reflects the fact that the majority of pond furniture waste arising at this site hasalready been retrieved and managed, owing to the maturity of the decommissioningprogramme. The remaining sites – Harwell (managed by RSRL) and Oldbury,Chapelcross, Dungeness A and Sizewell A (managed by Magnox Ltd.) – haveapproximately 1% of the pond furniture inventory respectively.Figure 3 – Total volume of pond furniture waste (m 3 ) within NDA estateTotal volume: 14315.41m 34.3. Waste typesPond furniture is metallic waste but consists of a variety of different types of metal. Figure4 shows the breakdown of waste types at the different sites. The waste identified at theMagnox Ltd. sites (Bradwell, Chapelcross, Dungeness A, Oldbury and Sizewell A)consists entirely of painted mild steel pond skips. The Sellafield waste inventory consistsof a mixture of mild steel and stainless steel, with the majority (approximately 95%) beingstainless steel. A proportion of the mild steel pond furniture at Sellafield is surface coated(painted). The greatest variation in waste type is seen at the Harwell site, where the wasteis a mixture of stainless steel (approximately 60% of the inventory), aluminium(approximately 31% of the inventory) and lead (9%).A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 16 of 58Figure 4 – Proportions of pond furniture volume (m 3 ) by type for each relevant site in theNDA estateA company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 17 of 584.4. Radiological ClassificationFigure 5 illustrates the breakdown of the pond furniture inventory within the NDA estate byradiological classification, indicating that the majority of the inventory within the scope ofthis study is believed to be classifiable as LLW (approximately 90%). The entirety of thewaste from the Magnox Ltd. sites is expected, based on history and provenance, to beclassifiable as ILW / LLW cross-boundary waste and the entirety of waste from Harwell isexpected to be classifiable as LLW. Sellafield Ltd. estimates a split in the classification oftheir waste inventory, with approximately 95% expected to be LLW and 5% ILW / LLWcross-boundary waste. In reality, it is expected that these breakdowns may be differentthan stated owing to the assumption that waste classifications have been derived basedon history and provenance, rather than underpinning characterisation. Also, it should benoted that the waste inventory of certain sites, specifically Sellafield Ltd., also holds aninventory of pond furniture classifiable as ILW which is not reported in this study.Figure 5 – Breakdown of pond furniture volume (m 3 ) by radiological classification in theNDA estateILW / LLW10%LLW90%4.5. Schedule for waste generationAn indicative schedule for retrieval of pond furniture waste for management for the period2012-2100 is provided in Figure 6. Management of pond furniture and decommissioning ofthe pond structures for Magnox Ltd. is expected to be undertaken in the relatively nearterm in order to meet the corporate vision for transfer of sites into Care and Maintenanceby 2028. It should be noted that there is variation in the timetable for these activities atdifferent sites [Ref. 9, 10]. There is a similar picture for decommissioning of the fuelstorage pond at Harwell, with completion of decommissioning and associated wastemanagement by the mid 2020s [Ref. 11, 12]. Timescales at Sellafield are more elongated,with efforts in the near term relating to retrievals from, and decommissioning of, the legacyponds facilities (FGMSP and PFSP), as per the Sellafield Ltd strategic imperative of riskand hazard reduction [Ref. 13]. Retrievals of pond furniture associated with the fuelstorage ponds for Light Water Reactor (LWR) fuel and Advanced Gas-Cooled Reactor(AGR) fuel occur over a longer period of time, to enable completion of the commercialreprocessing mission and to support ongoing decommissioning of other related facilities.A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 18 of 58Figure 6 – Schedule of pond furniture waste retrievals within NDA estate 2012-2100A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 19 of 585. Waste Management StrategiesA range of waste management strategies and approaches have been, and are currentlyused by the NDA estate for management of their pond furniture waste. The toolkit ofapproaches employed by any specific SLC reflects the overall strategic intent of that SLCand the availability of waste treatment routes, balanced against available funding andschedules for waste retrieval.This section of the document provides summaries of the overall waste managementstrategies and individual waste techniques used by the NDA estate SLCs. Section 5.1provides a high-level “state of the nation” description of the SLC or site wastemanagement strategy applicable to pond furniture. This includes a list of the techniques incurrent routine use for management of this waste for each SLC. This listing is expanded insection 5.2 where technology summaries are provided for each technique. The R&Dactivities undertaken by NDA estate SLCs relevant to pond furniture are briefly describedin section 5.3, with examples of any trials undertaken associated with the R&D. A range oftechniques not used or being trialled by SLCs has been identified through literature reviewand these are listed in section 5.4. Case studies relating to the use of any specifictechnique on pond furniture or wastes analogous to pond furniture by the NDA estateSLCs are presented throughout sections 5.2 and 5.3 to illustrate the technologysummaries.5.1. NDA Estate Waste Management StrategiesEach NDA estate SLC has specific strategies relating to management of their specificwaste inventories. This section identifies and briefly describes the strategy relevant tomanagement of pond furniture for each SLC with an inventory of this waste. This includesa list of the techniques in current and routine usage at each SLC for pond furnituremanagement.5.1.1. Magnox Ltd.Magnox Ltd’s strategy for management of its sites involves undertaking preparatory workfor Care and Maintenance until 2028, and then transfer of the sites into passive quiescentstate until 2075 (specific timings vary for individual sites). The preparatory work for Careand Maintenance involves undertaking dismantling work to remove radiological and nonradiologicalplant and buildings where benefit cannot be achieved from deferring the work.Waste retrievals, decommissioning and demolition of fuel storage ponds are a key part ofthis preparation for Care and Maintenance [Ref. 9, 10]. The strategy for pond furnituremanagement is to use decontamination as far as practicable to down categoriseradiological waste, and then to either divert waste for re-use / recycle or to dispose ofwaste to an appropriate facility, where a specific waste route is demonstrated to be BestAvailable Technique (BAT).The techniques previously considered, employed or under consideration by Magnox Ltd.for the management of pond furniture include:• Size reduction• Direct disposal to LLWR• Direct disposal to GDF• Optimised disposal to LLWR• Physical decontamination• Chemical decontaminationA company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 20 of 58• Metal meltingOther techniques, and specific decontamination techniques, will be kept under watchingbrief by Magnox Ltd., and trials carried out as appropriate as part of the demonstration ofBAT.5.1.2. Sellafield Ltd.Sellafield Ltd. is in the process of defining and developing a discrete strategy fordecommissioning of the Sellafield site, following on from the development ofDecommissioning Mandates undertaken during the latter half of 2000-2010. As aconsequence, the overall strategy for the management of pond furniture is underdevelopment. The situation at Sellafield is complicated by the diversity of the mission onthe site, particularly with regards to fuel storage ponds, as the facilities range from thosein active decommissioning (forming part of the risk / hazard reduction work ongoing onlegacy facilities) through to those currently still in active use to support commercialreprocessing operations [Ref. 13]. It is expected that the strategy for management of pondfurniture will continue to evolve as the mission of the site changes over time todecommissioning and site clearance. The current high-level strategy employed for themanagement of pond furniture at Sellafield involves size reduction, packaging anddisposal, with relatively little effort on treatment and diversion of waste. This is changing,with implementation of the National Strategy for LLW [Ref. 1] and other initiatives, togreater use of decontamination and technologies enabling re-use, re-cycle and diversionfrom disposal.The techniques employed or under consideration by Sellafield Ltd. for the management ofpond furniture include:• Size reduction• Direct disposal to LLWR• Direct disposal to GDF• Optimised disposal to LLWR• Physical decontamination• Metal melting5.1.3. Research Sites Restoration Ltd.The Harwell site, operated by RSRL, has one fuel storage pond facility which providedservices to the DIDO and PLUTO reactors. This fuel pond is in active decommissioning,with work to retrieve pond furniture wastes, draining of the pond liquors andcharacterisation of the pond structure [Ref. 11, 12]. Until recently, the strategy formanagement of pond furniture wastes arising from this facility was to size reduce (asnecessary), package the waste and transfer to LLWR for disposal. The greater availabilityof different waste routes to RSRL and the Harwell site have contributed to a shift in thisstrategy with a new approach being implemented to utilise waste treatment services (e.g.metal melting) to facilitate diversion of waste away from the LLWR.The techniques employed by RSRL for the management of pond furniture include:• Size reduction• Direct disposal to LLWR• Physical decontaminationA company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 21 of 58The techniques planned to be used by RSRL in the near future for management of pondfurniture include:• Shot-blasting• Metal melting5.2. Technology summaries - waste management approaches in routine useThis section provides a compilation of the strategies and approaches employed by sitelicence companies and the supply chain for the management of pond furniture waste. Itshould be considered that these techniques can be used separately or in combination;and that, as alluded to in section 3.3, combination of these techniques is typically requiredto achieve an acceptable waste management outcome.Each management strategy is presented as a separate section and provides:• A description of the approach.• A summary of which types of pond furniture the technique can be used on.• A description of the outcome of the use of the approach in terms of the primarywasteform (the pond furniture) and any secondary wastes 1 .• Identification of any advantages and disadvantages with the use of the technique.• Identification of which SLCs are using that specific technique.Case studies are included for a number of techniques to illustrate where and howparticular SLCs have employed the technique for management of pond furniture.Glossary of symbols in technology summariesApplicability to waste classificationsLLWLow Level WasteILW/LLWTechnology applicabilityILW / LLW Cross-Boundary WasteTechnology is applicable to the specific type of waste.Technology is potentially applicable to the specific type of waste.Technology is not applicable to the specific type of waste.Technology is not applicable to the specific type of waste but may be a usefulprecursor technology prior to use of another technique.Use of technologyMagnox Ltd. Sellafield Ltd. Research SitesRestoration Ltd.1 The technology summaries make reference to the Environmental Permitting Regulations 2010 (asA company owned by UK Nuclear Waste Management Ltdamended) out-of-scope classification, which is applicable in England and Wales. For simplicity, this shouldbe taken to refer to both this classification and the exempt classification used in Scotland under theRadioactive Substances Act 1993 (Scotland) [as amended] (RSA93) definition.NOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 22 of 585.2.1. Size Reduction [Ref. 5, 14, 15]Usage as standalone techniqueSurface contaminatedLLWAluminiumCopperMild steelMild steel (coated)Stainless steelILW/LLWStainless steel (coated)VolumetricallycontaminatedActivatedDescription of techniqueSize reduction is a set of techniques used to minimise the dimensions of an item or object. For pondfurniture, if not undertaken underwater size reduction is predominantly undertaken using so-called “coldcutting”mechanical techniques or laser cutting, to minimise the spread of contamination to atmosphere.Plasma cutting has been seen to be effective underwater as well as in dry environments.Examples of mechanical cold-cutting techniques used for size reduction of pond furniture include:• Mechanical saws (e.g. reciprocating saws) for size reduction of small or medium sized pond furniturecomponents.• Nibblers (which use reciprocation to nibble through small amounts of metal) used for thick mild orstainless steel components.• Diamond wire saws used for large components.Outcomes Advantages Disadvantages• Reduction in the size of pond furniturecomponents to facilitate further treatmentor disposal.• Secondary wastes are smaller volumes ofsolid metallic waste for treatment / disposaland tools / tool components.• Simple.• Applicable to widerange of metal types.• Applicable to wideactivity range.• Minimised likelihood ofcontamination transferrelative to “hot-cutting”techniques.• Simple and easy tomanage secondarywastes.• Use of manualtechniques may bedifficult in high doseenvironments.• Can be difficult todeploy successfullyfor items of complexgeometry.Technique used at:A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 23 of 585.2.2. Surface Washing [Ref. 5, 14, 15]Usage as standalone techniqueSurface contaminatedLLWAluminiumCopperMild steelMild steel (coated)Stainless steelILW/LLWStainless steel (coated)VolumetricallycontaminatedActivatedDescription of techniqueThis is a technique which uses low pressure water (at either high or low temperature) to remove any watersoluble and loose debris from the surface of contaminated items. This technique can be applied at closerange, at distance or remotely (depending on the space and dose constraints of the area). The efficacy ofcleaning can be improved by the addition of detergents and solvents to the water but this can make disposalof the liquid secondary waste more complex. This has been found to be most useful for the removal of bulksolids or sludges from the surfaces of metallic items.Outcomes Advantages Disadvantages• For LLW:o Waste metal decontaminated toEPR out-of-scope status forunrestricted release for re-use orrecycle; oro Waste metal decontaminated toenable further processing,recycling or disposal.• For ILW / LLW cross-boundary wastes:o Waste metal decontaminated toLLW classification to enable furtherprocessing, recycling or disposal.• Secondary wastes – could potentiallygenerate a large volume of radiologicallycontaminated aqueous spent washingliquors (potentially contaminated withdetergents and solvents).A company owned by UK Nuclear Waste Management Ltd• Simple.• Applicable to widerange of metal types.• Applicable to wideactivity range.• Can be appliedremotely or atdistance.• Cannot remove fixedcontamination.• Not useful forvolumetricallycontaminated oractivated metals(unless as precursorstep for furthertreatment).• Generates largevolume ofradiologicallycontaminatedaqueous wasterequiring disposal.• Potential for orphansecondary wastegeneration.• Effectiveness limitedby complexgeometries orinaccessible wastes.NOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 24 of 58Technique used at:A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 25 of 585.2.3. Surface Wiping [Ref. 5, 14, 15]Usage as standalone techniqueSurface contaminatedLLWAluminiumCopperMild steelMild steel (coated)Stainless steelILW/LLWStainless steel (coated)VolumetricallycontaminatedActivatedDescription of techniqueThis manual decontamination technique involves the physical removal of loose debris and dusts from thesurface of the waste item through wiping or vacuuming. Wet wiping is used to remove debris or dusts whichcannot be removed by dry wiping either through the use of a liquid soaked wipe or by spraying water /chemicals onto the surface of the item and wiping it off. The application of pressure during wiping ofcontaminated surfaces can remove any loosely adhering contamination.Outcomes Advantages Disadvantages• For LLW:o Waste metal decontaminated toEPR out-of-scope status forunrestricted release for re-use orrecycle; oro Waste metal decontaminated toenable further processing ordisposal.• For ILW / LLW cross-boundary wastes:o Waste metal decontaminated toLLW classification to enable furtherprocessing or disposal.• Secondary wastes – high volume ofradiologically contaminated solid wipes /swabbing materials (potentiallycontaminated with detergents or solvents)or solid dust / debris collected by vacuum.Technique used at:• Simple.• Applicable to widerange of metal types.• Applicable to wideactivity range.• Cannot remove fixedcontamination.• Not useful forvolumetricallycontaminated oractivated metals(unless as precursorstep for onwardtransfer).• Manual method –may not bepracticable in highdose environments.• Effectiveness limitedby complexgeometries orinaccessible wastes.A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 26 of 585.2.4. Mechanical Surface Decontamination (Ultra-High Pressure Water Jetting) [Ref. 5,14, 15]UsageLLWILW/LLWSurface contaminatedVolumetricallycontaminatedActivatedAluminiumCopperMild steelMild steel (coated)Stainless steelStainless steel (coated)Description of techniqueUltra-high pressure (UHP) water jetting is a mechanical decontamination technique which uses ultra-highpressure water to physically remove contamination from the surface of an object. The technique can beapplied manually using hand-held apparatus or remotely; either in-situ or within closed boxes. UHP waterjetting can be used to remove surface coatings (e.g. paint) from surfaces and can be used to remove surfacedeposits without damaging underlying metal surfaces. Decontamination may be improved through the use ofheated water or the addition of abrasives, solvents or detergents to the water.Outcomes Advantages Disadvantages• For LLW:o Waste metal decontaminated to EPRout-of-scope status; oro Waste metal decontaminated to enablefurther processing.• For ILW / LLW cross-boundary waste:o Waste metal decontaminated to EPRout-of-scope status; oro Waste metal decontaminated to LLWto enable further processing ordisposal.• Secondary wastes include large volume ofradiologically contaminated aqueous waste(may contain abrasives, solvents ordetergents if used).A company owned by UK Nuclear Waste Management Ltd• Quick and relativelysimple.• Applicable to a widerange of metals.• Applicable to a widerange of radiologicalactivities.• Useful for theremoval of surfacecoatings.• Less useful for complexgeometries whereuniform coverage of theitem may not beattained.• Not useful forvolumetricallycontaminated oractivated metals (unlessas precursor step foronward transfer).• Large volume ofsecondary wastesgenerated.• Potential for orphansecondary wastegeneration.• Can be dose-intensive ifnot used in automatedconfiguration.NOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 27 of 58Technique used at:LLWILW/LLWCase Study A – UHP Water Jetting of Pond Skips at BradwellChallengeTo support accelerated decommissioning of the Bradwell site, a variety of decontamination techniques weretrialled on the ILW / LLW cross-boundary pond skips retrieved from the Bradwell fuel storage pond. One trialtested whether removal of the painted surface coating on a pond skip would reduce the radioactivitysufficiently to enable the waste to be classified and managed as LLW.SolutionUHP water jetting was trialled on a skip as part of this programme. UHP water jetting was used withpressures exceeding 1700 bar using a bespoke built-for-purpose containment system. The trialsuccessfully removed the surface paint from the fuel skip, allowing the skip to be processed as LLW. Theprocess generated approximately 12m 3 of waste water with solids including paint flakes entrained in thewater. The water was allowed to settle and 0.35m 3 of solids were separated and collected for disposal.A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 28 of 585.2.5. Mechanical Surface Decontamination (Shot-Blasting) [Ref. 5, 14-17]UsageLLWILW/LLWSurface contaminatedVolumetricallycontaminatedActivatedAluminiumCopperMild steelMild steel (coated)Stainless steelStainless steel (coated)Description of techniqueShot-blasting is undertaken either using SLC infrastructure where available (e.g. the Metal RecyclingFacility at Sellafield) or else within the supply chain (e.g. the Studsvik UK Metal Recycling Facility atLillyhall, Cumbria). Metal is received at appropriate facility, inspected; size reduced as required and issubject to shot-blasting. Shot-blasting is a process by which the metallic waste is subjected to a stream ofhigh-pressure abrasive material; and the friction of the abrasive material removes deposits from thesurface of the item and a thin layer of the metal surface. This removes any surface contaminated layerfrom the item. It should be noted that this technique may be problematic for stainless steels, particularlywhere contamination is ingrained into the metal surface.Specific restrictions exist within the Waste Acceptance Criteria (WAC) for dose rate, surface contaminationlevels, individual item weight and acceptability of surface coated metals. Acceptability of wastes outsidethe WAC specification would require assessment and decision on a case-by-case basis (for example, thishas been successfully undertaken for waste management of the Sellafield MEBs).The Sellafield Metal Recycling Facility is currently used exclusively for the Sellafield site and processesferrous metal through shot blasting (the facility cannot accept aluminium or copper for treatment by shotblasting).The facility can accept metal at relatively low contamination levels (

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 29 of 58• For ILW / LLW:o Waste metal decontaminated to LLWstatus to enable for further processingor disposal.o Secondary wastes – mixture of blastmedia and surface wastes. This isdisposed of via disposition at LLWR ormay be returned to the customer formanagement if higher activity.• Not useful forcomplex geometriesunless size reduced.Technique used at:A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 30 of 585.2.6. Mechanical Surface Decontamination (Spongejet) [Ref. 5, 14, 15]UsageLLWILW/LLWSurface contaminatedVolumetricallycontaminatedActivatedAluminiumCopperMild steelMild steel (coated)Stainless steelStainless steel (coated)Description of techniqueSpongejet is a mechanical surface decontamination technique which uses a shot abrasive enclosed withinsponge media. The material is jetted at high speed against the surface of the contaminated item, uponwhich impact the sponge structure flattens to expose the abrasive. Upon leaving the surface of the item, thesponge media expands and creates a vacuum that entraps the contamination (which would have otherwisebecome airborne). The media can be recycled typically up to ten times. The process is typically operatedremotely, within a containment shield, to provide protection to operators. The secondary waste produced bythe process is a dry solid waste - the spent spongejet media.Outcomes Advantages Disadvantages• For LLW:o Waste metal decontaminated to EPRout-of-scope status; oro Waste metal decontaminated to enablefor further processing.o Secondary wastes – radiologicallycontaminated spent blast media.• For ILW / LLW:o Waste metal decontaminated to LLWstatus to enable further processing ordisposal.o Secondary wastes – radiologicallycontaminated spent blast media.Technique used at:• Applicable to widerange of metal types.• Applicable to wideactivity range.• Reduces volume ofcontaminated wasterequiring disposal.• Produces secondarywaste which is easy toretrieve, handle andmanage.• Not useful forvolumetricallycontaminated oractivated metals(unless as precursorstep for onwardtransfer).• Manual process.A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 31 of 58LLWILW/LLWCase Study B – Spongejet decontamination of pond furniture at Hunterston AChallengeHunterston A identified a need to develop improved capabilities for the decontamination and management ofsurface contaminated metal, including pond furniture.SolutionSpongejet technology had been used by Hunterston A since 2006 for the treatment and management ofcontaminated steel. A Spongejet KwietKave system was installed and commissioned at the facility toenable more contained and automated use of the process. This has been undergoing trials since 2011,and has proved to be successful with the processing of approximately 50te of contaminated metal to date.A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 32 of 585.2.7. Chemical Decontamination (strong mineral acids) [Ref. 5]UsageLLWILW/LLWSurface contaminatedVolumetricallycontaminatedActivatedAluminiumCopperMild steelMild steel (coated)Stainless steelStainless steel (coated)Description of techniqueStrong mineral acids – such as sulphuric acid, hydrochloric acid, nitric acid or phosphoric acid – areparticularly useful for the removal of contamination from metals. The action of the strong mineral acid on themetal surface dissolves metal oxide films and improves the solubility of metal ions, thus removing surfacecontamination from the metal object. These may be applied as a solution, paste, gel or foam by a variety ofapplication methods including jetting, swabbing, wiping or spraying. The performance of the technique isdependent on the nature of the material to be decontaminated, the type of contamination and the geometryof the object.The technique is applicable to mild steel, stainless steel, aluminium and copper; and can be utilised fordecontamination of LLW or ILW/LLW. The technique is for surface decontamination and is not useful forvolumetric contaminated or activated waste, other than a precursor to other waste treatment.Outcomes Advantages Disadvantages• For LLW:o Waste metal decontaminated to EPRout-of-scope status; oro Waste metal decontaminated to enablefor further processing.o Secondary wastes – acidic liquidradioactive waste.• For ILW / LLW:o Waste metal decontaminated to LLWstatus to enable further processing ordisposal.o Secondary wastes – acidic liquidradioactive waste.A company owned by UK Nuclear Waste Management Ltd• Mature technology.• Potentially applicableto LLW/ILW borderlinewastes.• Generates a largevolume of acidicliquid radioactivesecondary wastesrequiring treatmentand disposal.• Technique poseschemical hazards –e.g. corrosivity,toxicity and adversechemical reactivity.• Not useful forvolumetricallycontaminated andactivated wastes(unless as precursorto other wastetreatment).NOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 33 of 58• Potential forincompatibility ofmetal type with aspecific acid; e.g.copper waste canadversely react withnitric acid to generatetoxic NOx fumes.• Potential forgeneration of orphansecondary wastes.Technique used at:ILW/LLWCase Study C – Nitric acid decontamination at Hunterston AChallengeAs part of ongoing deplanting of the fuel storage pond at Hunterston A, 200 aluminium ILW pond skips wereidentified as requiring a waste management solution.SolutionA chemical decontamination technique using nitric acid was identified as a solution for the Hunterston A fuelskips. The skips were retrieved from the pond and decontaminated to LLW using a warm (60°C) solution of6% nitric acid, utilising existing equipment in the skip refurbishment plant. Following decontamination withthe nitric acid, the skips were size reduced and coated to meet the acceptance criteria for LLWR. Certaincomponents were compacted following coating to reduce the volume of the waste. The waste waspackaged into half-height ISO containers and transferred to LLWR for disposal.The process generated a significant volume (approximately 140m 3 ) of ILW contaminated liquid secondarywaste – the depleted nitric acid containing dissolved contamination and some dissolved aluminium. This hasrequired specialist interim storage in a purpose built acid storage facility pending encapsulation.A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 34 of 585.2.8. Metal Melting [Ref. 5, 14-16, 18-20]UsageLLWILW/LLWSurface contaminatedVolumetricallycontaminatedActivatedAluminiumCopperMild steelMild steel (coated)Stainless steelStainless steel (coated)Description of techniqueMetal melting is a technology available to SLCs via the supply chain. There are three main facilitiesavailable for the melting of radiologically contaminated metal – Studsvik, Sweden; Siempelkamp, Germany;and Bear Creek, USA.At all facilities, the basic process is the same - the waste is received at the facility, characterised and sizereducedwhere required prior to melting (decontamination by shot blasting may also be applied prior tomelting by Studsvik and Siempelkamp). The metal is melted in an induction furnace which results inconcentration of radioisotopes into the floating slag layer. This floating layer can be collected from the bulkmetal and packaged for storage and disposal. This results in a homogenised bulk metal of significantly loweractivity than the feedstock metal.For LLW, the fate of the metal is dependent on the location of treatment:• At Studsvik the homogenised bulk metal is cast into ingots and sold for recycling. This results in asignificant reduction in the volume of the radioactive waste for disposal (typically by 95-96%,although this is variable dependent on the size of the component being melted). The secondarywaste (slag, filter dust, furnace lining) is returned to the customer for disposal or else is disposed ofdirectly to LLWR via the Studsvik Metal Recycling Facility at Lillyhall.• At Siempelkamp, the homogenised bulk metal is cast into blocks and released for recycling, or elseis cast into shielding or waste containers for use in the nuclear industry. The secondary waste (slag,filter dust and furnace lining) is returned to the waste generator for disposal.• At Bear Creek, the homogenised metal is cast into shield blocks for use in the nuclear industry. Anysecondary waste arising from the process (e.g. slag, filter dust, furnace lining) is disposed of byEnergySolutions in the USA and there is no repatriation of waste to the UK.Specific restrictions exist within the Waste Acceptance Criteria (WAC) for each facility relating to:• Dose rate• Surface contamination levels• Individual item weight• Acceptability of surface coated metalsA company • owned Metal by UK type Nuclear (EnergySolutions Waste Management Bear Ltd Creek, USA facility is unable to process non-ferrous metals).NOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 35 of 58Detail on the specific restrictions is provided in the facility WAC or else on discussion with Studsvik orEnergySolutions. Acceptability of wastes outside the WAC specification would require assessment anddecision on a case-by-case basis.There is some potential for melting of higher activity metallic wastes (i.e. ILW / LLW boundary wastes) atthese facilities but in this case, the partitioning of the radioactivity from the bulk metal may not be completeand so the resultant bulk metal would require either further treatment (where practicable), disposal as LLWor casting into components for use in the nuclear industry. Use of this technology / location would require anassessment of feasibility of the process on a case-by-case basis.Outcomes Advantages Disadvantages• For LLW (depending on treatment facility):o Bulk metal de-classified to exemptand released for unrestrictedrecycling / re-use; or bulk metalclassified to lower activity andrecycled to shielding or wastecontainers for re-use in nuclearindustry.o Small volume (4-5%) LLWsecondary waste (slag, filter dust,furnace lining) for disposal.• For LLW / ILW boundary waste:o Bulk metal de-classified to LLW forfurther treatment or disposal orrecycled to shielding or wastecontainers for re-use in nuclearindustry.o Small volume of LLW (highlyactive) or ILW secondary waste(slag, filter dust, furnace lining) fordisposal or storage (pendingdisposal to GDF) by customer.Technique used at:• Potential to recyclemetal, minimisingvolume of radioactivewaste requiringdisposal.• Mature technology.• Potentially applicableto LLW/ILW borderlinewastes.• Useful forvolumetricallycontaminated andactivated wastes.• Restrictions on dose,contamination andmaterial type maylimit applicability.• Management ofLLW/ILW wastes viathis process may takean extended period oftime.A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 36 of 58LLWILW/LLWCase Study D – Metal Melting of Sellafield Ltd. MEBsChallengeSellafield Ltd. possesses a significant number of multi-element bottles (MEBs) previously used for thestorage of LWR fuel assemblies in ponds pending re-processing; the waste was a mixture of LLW and ILWof varying levels of contamination. To assist hazard reduction and to optimise the waste storage capacity onsite,Sellafield Ltd. sought a waste management solution for these wastes.SolutionIn 2011/12, a project was undertaken between Sellafield Ltd. andStudsvik Ltd. (via the LLWR Ltd. Segregated Service Framework)for the treatment and disposal of 10 MEBs of higher activity (in therange of 752MBq to 3.72GBq total activity per MEB), two of whichwere classified as ILW. The ILW classification MEBs weredecontaminated by Sellafield Ltd. to LLW classification by in-situunderwater pressure jetting. The MEBs were then transferred to theStudsvik MRF facility for size reduction prior to transfer to theStudsvik Metal Treatment and Recycling Facility in Sweden formetal melting. The use of metal melting in this project resulted in theavoidance of disposal of 5 ISO containers worth of metal at the LowLevel Waste Repository, as well as significant cost savings forSellafield Ltd. in the decontamination of ILW to LLW.Figure 7 – MEB at Studsvik UK MetalRecycling Facility pending sizereduction.A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 37 of 58ILW/LLWCase Study E – Metal Melting of Ferrous Fuel Skips from Hinkley Point AChallengeDeplanting of fuel cooling ponds at Hinkley Point A Nuclear Power Plant (Magnox Ltd.) produced 185te offerrous metallic pond skips, previously used for the wet storage of irradiated nuclear fuel. A wastemanagement solution for the treatment and disposal of this waste (classified as LLW, with average activity 5GBq/te of predominantly Cs-137, Sr-90 and C-14).SolutionBetween 2007 and 2010, a project was undertaken in collaboration between Magnox Ltd. andEnergySolutions for the management of this waste. Magnox Ltd. undertook the partial decontamination ofpond skips to facilitate their transfer off-site for treatment. The pond skips were packed into 15 half-heightISO containers (HHISO) and shipped to the Bear Creek facility in Tennessee for melting (Figure 8).Undertaking this project has diverted these 15 half-height ISO containers away from disposal at the LLWR;with 95% recycled as shield block material (Figure 9) and sold for re-use in the nuclear industry, with theremaining 5% of secondary waste disposed of at EnergySolutions Clive facility in the USA.Figure 8 – Metal melt andpour process at Bear Creek.Figure 9 – Cast recycled metalshield blocks at Bear Creek.This project is ongoing with a number of skips awaiting treatment, owing to the high activity of the skipstransferred for processing.A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 38 of 585.2.9. Optimised Disposal to Low Level Waste Repository (LLWR)UsageLLWILW/LLWSurface contaminatedVolumetricallycontaminatedActivatedAluminiumCopperMild steelMild steel (coated)Stainless steelStainless steel (coated)Description of techniqueOptimised disposal is a methodology which facilitates disposal at the Low Level Waste Repository involvingthe disposal of two or more wastestreams in the same disposal volume, so as to maximise the use of thedisposal volume capacity and minimise the use of inactive grout infill. This methodology is most useful, inthe context of pond furniture, for the management of pond skips and containers for which other wastemanagement approaches are not suitable and for which size reduction is not practicable. Optimiseddisposal would involve such skips or containers being transferred into an appropriate disposal container;and the voidage within the pond skips or containers filled with additional different radiologicallycontaminated wasteforms and cementitious grout. The voidage around the skips or containers within thedisposal container is similarly filled with the waste / grout mixture or different additional wastes, either allfrom the same waste producer or a mixture from different waste producers. The disposal container is thentransferred to the LLWR for final grouting and disposition.It should be noted that this management approach, as it requires waste disposal at the LLWR, should beconsidered as a last resort and would involve significant assessment by LLWR Ltd. The use of thisapproach would only be deemed acceptable where every reasonably practicable effort has been made toemploy alternative conditioning, treatment and disposal routes.This approach would be suitable for all waste types and potentially for ILW / LLW borderline wastes; butwould require significant up-front dialogue with LLWR Ltd.Outcomes Advantages Disadvantages• Waste transferred to LLWR for finaldisposition,• Optimised use of disposal volume.• Secondary wastes dependent onwasteforms included in optimised disposalmodel.A company owned by UK Nuclear Waste Management Ltd• Useful for situationswhere size reductionand othermanagementapproaches are notpracticable.• Optimises use of thedisposal volume atLLWR.• Requires disposal ofwaste at LLWR, usingvaluable disposalcapacity.• Removesopportunities forbeneficial re-use ofmetal.NOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 39 of 58Technique used at:LLWCase Study F – Optimised Disposal of Pond Skips from Bradwell (Magnox Ltd.) byEnergySolutions and InutecChallengeTo support accelerated decommissioning of the Bradwell site, some 117 pond skips were removed from theBradwell fuel cooling pond, completing during 2009. These pond skips were classified as higher activityLLW, and owing to various physical, radiological and schedule constraints it was deemed that it was notpracticable for these pond skips to be decontaminated by high pressure jetting to enable recycling or forsize reduction. The only option was for disposal of the skips.SolutionA project was initiated by EnergySolutions, in collaborationwith Inutec, Bradwell and LLWR Ltd, in 2011 to enable theoptimised disposal of these pond skips. The pond skips hadbeen loaded into dumpy bags, to facilitate contaminationcontrol, by Bradwell and transferred into half-height ISOcontainers. These were transferred in batches to the Inuteclicensed site at Winfrith licensed site for processing. AtInutec, the HHISO containers were opened, subjected toHealth Physics monitoring and the pond skips infilled withadditional wastes. Processing of the pond skip wasundertaken in stages:• The outer voidage around the dumpy bags was infilledwith cemented waste desiccant, from another wastegenerator.• The dumpy bags were cut open and a contaminationfixative applied.• The skips were infilled with cemented waste desiccant(Figure 10).• Supercompacted waste pucks were then added to theHHISO to fill additional void space (Figure 11).This optimised disposal model facilitated disposal of thesepond skips at LLWR whilst enabling a 50% reduction in thedisposal volume and a 90% reduction in inactive grout infill.Figure10 – Waste processing rig at InutecFigure 11 – ISO container being filledwith pucks of supercompacted waste atInutecA company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 40 of 585.2.10. Direct Disposal to Low Level Waste Repository (LLWR)UsageLLWSurface contaminatedVolumetricallycontaminatedActivatedAluminiumCopperMild steelMild steel (coated)Stainless steelStainless steel (coated)Description of techniqueWaste metal is characterised, size reduced (as required) and packed into appropriate ISO disposalcontainers. Size reduction / compaction etc. is used to ensure that inaccessible voidage within the disposalcontainer is minimised as far as practicable. Additional LLW may be added to the containers to ensure bestuse of the disposal volume. These are transferred by rail or by road to the Low Level Waste Repository(LLWR) site in Cumbria, filled with cementitious grout and are then transferred into an engineered vault fordisposal.Specific restrictions relating to (but not limited to) waste type, radiological characteristics (total activity, fissilecontent, radiation, contamination), waste mass and voidage are specified in the waste acceptance criteria(WAC) for the facility.Outcomes Advantages Disadvantages• Waste disposed of at LLWR.• Secondary waste – solid wastes from sizereduction (e.g. diamond wire), waste grout.• Relatively simple.• Applicable to widerange of metal types.• Applicable to wideactivity range (up todefinition of LLW inLLWR WAC).• Uses up valuablewaste disposalcapacity at a nationalasset (LLWR).• Reduces opportunityfor re-use and recycleof waste.Technique used at:A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 41 of 585.2.11. Disposal to Geological Disposal Facility (GDF)UsageLLWILW/LLWSurface contaminatedVolumetricallycontaminatedActivatedAluminiumCopperMild steelMild steel (coated)Stainless steelStainless steel (coated)Description of techniqueWastes are suitably size reduced, conditioned and appropriately packaged (as per specific agreements andprotocols approved by the Radioactive Waste Management Directorate (RWMD)). The waste packages arethen interim stored by the waste generating site pending future transfer to and disposal at the GDF.Outcomes Advantages Disadvantages• For ILW / LLW cross-boundary wastes orLLW that does not meet the WAC forLLWR:o Waste metal conditioned andpackaged, as per RWMDspecifications, undergoing interimstorage pending future disposal.• Secondary wastes – any solid or liquidwastes arising from conditioning /packaging process (e.g. waste grout).• Suitable option forsome higher activitywastes for which otheroptions areunavailable.• Applicable to widerange of metal types.• Applicable to wideactivity range.• This does not providean early solution –GDF is not yetconstructed, requiringSLCs to retain andinterim store wastespending futuredisposal.• Disposal preventsany potential for recycleand re-use.Technique used at:A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 42 of 585.3. Technology summaries - pond furniture management R&DThis section provides a brief summary of the technologies that have been or are currentlybeing investigated by NDA estate SLCs in R&D programmes.A significant effort has been expended on research and development into wastemanagement approaches for pond furniture and other contaminated metals, particularlywith respect to decontamination techniques. Table 12 provides an overview of the keyresearch and development (both historical and current) pertinent to pond furniture. Thisoverview includes:• A brief description of the technique.• Identification of the key limitations and constraints in the use of the technique.• Identification of any trials undertaken by SLCs into the use of the technique.Any pertinent case study examples of this R&D – either on pond furniture or analogouswastes – are also provided to illustrate the purpose of the R&D and the outcome of thestudy.5.4. Other pond furniture waste management approachesA wide range of additional waste management practices have been developed within andoutwith the NDA estate for the management of waste metals, which may have synergiesor applicability to the challenges posed by pond furniture. As these waste managementapproaches are not in routine usage by SLCs, nor are the subject of specific R&D formanagement of pond furniture, detailed information on these techniques is not provided inthis document.Such techniques include:• Chemical decontamination – bases and alkaline salts• Chemical decontamination – bleaching• Chemical decontamination – organic solvents• Electrochemical decontamination – electropolishing / electrodeplating• Physical decontamination – dry ice crystal blasting• Physical decontamination – ice crystal blasting• Physical decontamination – laser ablation• Physical decontamination – scarifying, scabbling and planing• Physical decontamination – steam cleaning• Physical decontamination – thermal degradation• Physical decontamination – ultrasonic cleaningFurther detailed information about these waste management approaches is available onthe Environment Agencies Requirements Working Group (EARWG) website [Ref. 14].A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 43 of 58Table 12 – Summary of historic and current R&D into pond furniture managementTechnique Description Limitations and constraints Trials of process Outcome of trialsChemicaldecontamination (foam)[Ref. 14, 15]Foam decontamination is a chemical technique used toremove loose surface contamination and grease fromitems. The foam is a micro-dispersion of air and gas,which typically contains acids (either inorganic ororganic) and surfactants. Foams can be pumped orsprayed onto surfaces, and is suitable for either manualor remote deployment.The technique has the advantages of being relativelycheap, simple, with low residual levels of contaminationand is suitable for use on items with complexgeometries.• Only applicable to surfacecontaminated wastes.• Best suited to non-poroussurfaces (i.e. less useful forrusted surfaces).• Generates radiologicallycontaminated liquid secondarywastes.• Problems may be encounteredkeeping foam in-situ on verticalsurfaces; this can be overcomeby the use of organic additivesbut these may make secondarywaste disposal more complex.• Decontamination ofpond skips andpipelinesassociated withcooling pondsystems withchemical foam atSellafield (SellafieldLtd.).Foamdecontaminationdemonstrated to betechnically feasibleand to deliverappropriate level ofdecontamination ofpond skips andpipework.Foamdecontamination hasseen some routineuse for non-pondfurniture wastes(e.g. transportflasks).A company owned by UK Nuclear Waste Management Ltd• Technique potentially poseschemical hazards – e.g.corrosivity, toxicity and adversechemical reactivity.NOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 44 of 58Technique Description Limitations and constraints Trials of process Outcome of trialsDFD [Ref. 21]DFD is a chemical decontamination process whichinvolves the treatment of surface contaminated metalobjects with dilute fluoroboric acid with a controlledoxidation potential. This process removes the outerscale and a thin surface layer of metal, thus removingsurface contamination from the metal. The fluoroboricacid is recirculated through the system and isregenerated through an ion exchange system. Use ofthis process enables the re-classification of metal eitherto EPR out-of-scope (thus allowing for unrestrictedrecycling and reuse) or else to a state where the metalis suitable for alternate metal treatment (e.g. shotblasting,metal melting etc.). The secondary waste fromthe process consists of the spent dilute fluoroboric acidand the spent ion exchange resin.The system can be deployed at either high or lowtemperature, depending on the nature of thecontamination on the metallic waste and the constraintson the waste owner. High temperature processing ismore aggressive and is particularly suited to situationswhere contamination of the item has occurred in hightemperature environments. The process can bedeployed either from a mobile plant at the wasteA company owned by UK Nuclear Waste Management Ltdowners site or else at an appropriately licensed off-sitelocation.• Only applicable to surfacecontaminated wastes, unlessas a precursor to step to otherwaste treatment.• Only applicable to paintedsurfaces where paint is in poorcondition.• Wylfa titanium heatexchanger plates[case study G]DFD demonstratedto be successful indecontamination ofWylfa heatexchanger plates toexempt levels.Work is ongoingbetween Bradtec /ONET Technologiesand Studsvik UK toundertake activetrials of the systemon items of pondfurniture and todevelop a serviceoffering.NOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 45 of 58Technique Description Limitations and constraints Trials of process Outcome of trialsDFDX [Ref.22]DFDX is a variant of the DFD process, and is achemical decontamination process which involves thetreatment of surface contaminated metal objects (sizereduced when required) with dilute fluoroboric acid witha controlled oxidation potential. This process removesthe outer scale and a thin surface layer of metal, thusremoving surface contamination from the metal. Thefluoroboric acid is recirculated through the system andis regenerated through an electrochemical cell. The useof the electrochemical cell enables the metal ions in thespent fluoroboric acid to be converted to a solid metalparticulate, which can be collected and removed fordisposal. This reduces the volume of secondary wasterequiring management by the waste owner, relative tothe DFD process. Use of this process enables the reclassificationof metal either to EPR out-of-scope (thusallowing for unrestricted recycling and reuse) or else toa state where the metal is suitable for alternate metaltreatment (e.g. metal melting).• Less useful on simplegeometries.• Only applicable to surfacecontaminated wastes (unlessas a precursor step to otherwaste treatment technologies).• Only applicable to paintedsurfaces where paint is in poorcondition.• Trialled at HinkleyPoint A (MagnoxLtd.) to testwhether DFDXcould be used forpaint removal andmetaldecontamination ofa fuel skip.DFDX observed tobe successful inmetaldecontamination.Further trials orusage of the systemfor pond furnitureitems in UK nuclearindustry has beenlimited.The system can be deployed at either high or lowtemperature, depending on the nature of thecontamination on the metallic waste and the constraintson the waste owner. The process can be deployedeither from a mobile plant at the waste owners site orA company owned by UK Nuclear Waste Management Ltdelse at an off-site location.NOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 46 of 58Technique Description Limitations and constraints Trials of process Outcome of trialsGarnetBlasting [Ref.14, 15]Garnet blasting is a mechanical surfacedecontamination technique which uses garnet (amixture of various silicate chemicals) as an abrasivewhich is propelled in a high-energy jet stream at atarget area, which abrades away the contamination.This is often used in conjunction with UHP water jetting.• The technique is most effectiveon flat surfaces – items withmore complex geometries maysee a reduction in efficacy.• Only applicable to surfacecontaminated wastes (unlessas precursor step to otherwaste treatment methods).• Process generates a largevolume of secondary waste,owing to the volume of abrasivemedia and water used.• Trialled at Bradwell(Magnox Ltd.) totest effectivenessof process on pondfurniture and othercontaminatedmetals.Garnet blastingobserved to beeffective in thesurfacedecontamination ofmetal but has notbeen progressed tofurther trials orroutine usage owingto the large volumeof secondary wasteand the limitedlifespan of themedia.• Garnet has a limited lifespandue to disintegration of themedia.A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 47 of 58Technique Description Limitations and constraints Trials of process Outcome of trialsMetal milling[Ref. 14, 15]Rotary grinders and milling machines are used toremove thin layers of the item surface in order toremove surface contamination. The secondary wastearisings are the solid metal shavings, which are easilyretrieved. There is some potential for liquid secondarywastes from lubrication of the milling machine.Milling can be deployed remotely, reducing operatordose, using computer numeric control (CNC) millingmachines. They operate in a dry environment, avoidingthe creation of wet secondary waste, and often have anenclosure to minimise the spread of contamination.• May be time-consuming,especially when changingbetween configurations fordifferent geometries of items.• May leave some residualsurface contamination(depending on technique).• Potential for generation ofpyrophoric dust production ifused on aluminium.• Trial undertaken atBradwell during2012 to test theviability of millingas adecontaminationtechnique forcontaminated metal(particularly skips).Milling proved to besuccessful in theremoval of surfacecontamination and asmall surface layerof metal.Larger scale activetrials of thetechnology are to beundertaken atHinkley Point A andChapelcross in thenear future.A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 48 of 58Technique Description Limitations and constraints Trials of process Outcome of trialsNitrocision[Ref. 14, 15]This is a cryogenic decontamination technique involvingthe application of liquid nitrogen at high pressure andlow temperature to decontaminate the surface of items.The surface residues can be removed either throughvibration, ultrasonic cleaning or the inclusion ofabrasive media in the liquid nitrogen.This technique produces minimal secondary wastes(i.e. only the actual surface material removed by theprocess, with evaporation of the nitrogen and release toatmosphere).• Process is undergoingdevelopment for transfer intothe nuclear industry – this maypresent challenges in terms ofscale of use.• Health and safety risksassociated with the use ofcryogenic materials.• Limited to use on surfacecontaminated items.• Inactive trials havebeen undertakenby Magnox Ltd.Techniquedemonstrated toremove theprotective coatingfrom skip surfacesand potential fordecontaminatingbase metal with theuse of abrasive inthe nitrogen streamdemonstrated.A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 49 of 58LLWILW/LLWCase Study G – DFD decontamination of Wylfa heat exchanger platesChallengeWylfa Nuclear Power Station (Magnox Ltd.) identified a contamination issue with heat exchanger plates,which require periodic refurbishment by an off-site contractor. These heat exchanger plates are used in thecooling loop on the pressure vessel to remove heat from the cooling water before it is discharged to sea.These plates are subject to mildly radioactive deposits from the precipitation of iron corroded from the carbonsteel pipe work in the system. Removal of these deposits was deemed necessary to enable the transfer ofthe waste to an off-site contractor for refurbishment.SolutionBradtec worked with Wylfa to deploy the mobile DFD process rig at an appropriately licensed off-sitelocation. The plates were subject to the DFD process which successfully removed the mildly radioactive irondeposits from the complex heat exchanger plate geometries, generating a small volume of contaminated ionexchange resin disposed of by Wylfa. This project facilitated the unrestricted release of 1500 heat exchangerplates for refurbishment and re-use on site at Wylfa.Figure 13 – Wylfa Heat Exchanger plateprior to application of DFD processFigure 14 – Wylfa Heat Exchangerplate post application of DFDprocessA company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 50 of 586. Waste Management Decision Making LogicAs illustrated by Section 5, a wide range of waste management approaches are appliedwithin the NDA estate for the management of pond furniture. The selection of wastemanagement approach for a specific item of waste is undertaken by identification of BATthrough assessment a range of factors including (but not limited to) cost, scheduleconstraints, the characteristics of the waste, dose management and ALARP, the locationand accessibility of the waste, regulatory requirements etc. balanced against the definedstrategic direction for that plant / site / SLC [Ref. 23]. Despite this plant / site / SLCspecificity, a generic approach can be defined for the waste management decisionmaking process using the principles of the waste management hierarchy.This generic approach is summarised in a thought logic diagram in Figure 15. It should benoted that the purpose of this logic diagram is to provide an illustration of the relationshipbetween specific waste management approaches and waste management outcomesmapped using the principles of the waste management hierarchy, so as to identify keyareas for consideration in the decision making process, rather than to provide a rigidframework for waste practitioners to work to. Waste practitioners should use this decisionmaking logic in conjunction with their own waste management strategies and procedureswhen optioneering waste management strategies for pond furniture.A key point for consideration by waste management practitioners is the timing of thewaste management decision making process. Ideally, this should be undertaken as earlyas possible in the lifecycle of the waste (i.e. prior to the retrieval of waste wherepracticable). This enables timely characterisation and decision-making, minimising thelikelihood of operational and schedule constraints being realised. It is recognised that insome circumstances, this is difficult to achieve as operational reasons may requireretrieval of the waste before characterisation and waste management decision-makingcan be undertaken. The decision making process should consider the feasibility of downclassification of waste, volume reduction, disposal volume optimisation and the suitabilityof the waste for disposal (based on the earlier decisions) at appropriate disposal routes.Characterisation is a fundamental and vital element of the waste management process, inthat it generates a set of data describing the radiochemical, chemical and physicalproperties of the waste. The design and implementation of any characterisation schemeshould take account of, but not limited to, history / provenance of the item, the purpose /desired output of the study, cost, schedule constraints, the ease of accessibility of theitem, ALARP, and other health and safety considerations. Characterisation should ideallybe undertaken as early as possible in the lifecycle of the waste, so as to ensure thatwaste management options are not foreclosed at an early stage. For waste managementpractitioners, the output of the characterisation process should provide sufficientinformation on the radiochemical, chemical and physical characteristics of the waste toenable radiological classification of the waste and to enable adequate assessment of thesuitability of the waste against various management options.A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 51 of 58Figure 15 – Waste management thought logic diagram for management of pond furnitureNote: “practicable” in the context of this figurecorresponds to what has been demonstrated tobe BAT / BPM.A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 52 of 58Whilst it is accepted that waste management decisions are made by weighing up a varietyof factors including the characteristics of the waste, cost, schedule, ALARP, technology /waste route availability, and other health / safety factors, it should be noted that wastemanagement decisions should be directed by application of the waste managementhierarchy, illustrated in Figure 16, as far as practicable.Figure 16 – Waste Management HierarchyAVOIDMINIMISERE-USEIncreasingenvironmentaldetriment.RECYCLEVOLUME REDUCTIONDISPOSALFor pond furniture waste, as there are no opportunities to avoid generation of the wasteas the waste is extant, the focus for waste management practitioners should be onmaximising opportunities for minimising the volume of waste to be managed as LLW orILW through the use of treatment technologies such as metal melting or surfacedecontamination. Reducing the radiological classification of the waste provides greateropportunity for re-use and re-cycle, and greater opportunities for diversion away fromdisposal at LLWR or the future GDF, as well as providing a range of waste managementsolutions which are available in the nearer term than disposal facilities for higher activitywastes. This enables waste management practitioners to achieve earlier solutions for finaldisposal and discharge of liabilities. Only where re-use, recycle and down-classification ofwaste through treatment have been assessed and discounted as not being BAT shoulddisposal be considered as a viable waste management option.It should be considered that the application of waste treatment technologies often result inthe generation of secondary wastes. The type, volume, radiological classification andease of disposal of any such secondary wastes should be assessed in the wastemanagement optioneering process. In particular, careful consideration should be given tothe feasibility of generation of orphan wastes (either as secondary waste or as primarywaste). The management of orphan waste can be complex and costly for SLCs, and assuch the potential for the generation of orphan wastes through the application of anygiven technology should be assessed during the waste management optioneeringprocess. All practicable steps should be taken so as to minimise the generation of orphanwastes.A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 53 of 58For higher activity wastes (highly active LLW or ILW), the feasibility of decay storageshould be assessed as a mechanism to reduce the radiological classification of the waste.Assessment of the feasibility of decay storage is likely to include assessment of thecharacteristics of the waste and the probability of radioactive decay within an acceptabletimescale producing a waste of a lower radiological classification. This will also includeassessment of acceptable timescales, programme schedule, cost, storage capacity,interim or final site end-states, regulatory requirements and stakeholder concerns.Disposal of waste should be considered as the last resort and should only be soughtwhere it is justified as being BAT; although it is accepted that it may be the onlyacceptable waste management option in some cases. Given the demands that disposalcan pose – in terms of challenge to the finite disposal capacity for LLW disposal and interms of cost for ILW disposal – waste managers should take every practicable step tominimise the volume requiring disposal (for example, through the use of size reduction) orto optimise the use of the disposal volume (for example, through the use of co-disposal ofmetallic waste with other waste types).A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 54 of 587. Issues and OpportunitiesDuring development of this strategic guidance document, a number of issues genericacross the NDA estate have been identified. These issues pose barriers and challenges tothe effective management of pond furniture.The generic issues and barriers associated with management of pond furniture include:• A lack of centralised approach, leading to inconsistencies in the level of maturity ofdecontamination planning and implementation across the NDA estate. This contributesto duplication of effort (particularly with respect to R&D) or the perception of theduplication of effort.• The challenge of obtaining changes to environmental permits, for example in thecircumstances where an increase in discharge limits is required to supportdecontamination. There may be a tension in timescales and ideals between pondfurniture management programmes and the regulators.• Characterisation of pond furniture, whilst critical to waste management, is challengingas a consequence of the high-dose environments where the waste is located andlimited alternative buffer storage in lower-dose environments.• Operational difficulties in packaging and transport of pond furniture, particularly ILW /LLW cross-boundary wastes, impact the ability of SLCs to transfer waste into thesupply chain for treatment.• There is a requirement for R&D, as there is no “one size fits all” waste managementsolution owing to the significant variance in total activity and dose rate in the inventoryof pond furniture. Such R&D is costly and time consuming, and can create tension withthe programme for waste retrievals and decommissioning of fuel ponds.• There are limited facilities currently available on SLC sites with the capability to handlehigher activity (ILW / LLW cross boundary waste and ILW) pond furniture whichimpacts on the waste management approaches which can be employed.• There is a lack of centralised facilities, requiring each site to develop its own capability.This can adversely impact on the waste management approach which can beemployed, owing to limitations on economies of scale and constraints on individual sitefunding, schedule and end states.Allied to the issues and barriers associated with the management of pond furniture, thereare a number of opportunities to support improved efficacy of management of this wastewithin the NDA estate. These opportunities include:• Improved and more formalised linkages between SLCs to support the transfer ofknowledge and lessons learned, particularly with respect to R&D. It is recognised thatthere is communication between SLCs but this could be further augmented, as couldopportunities for collaborative working between SLCs.• The commercial viability of centralised facilities for the management of pond furnitureshould be investigated. This could be encouraged through engagement with the supplychain. Centralising approaches and facilities is likely to improved value throughcentralised R&D / technology transfer and better economies of scale.A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 55 of 588. ConclusionsThis strategic guidance document has compiled a baseline for the management of LLWand ILW / LLW cross-boundary pond furniture in terms of waste inventory, routinelyimplemented waste management approaches and historic / current R&D. This documentprovides the first comprehensive review of the management of lower activity pondfurniture within the NDA estate and provides waste practitioners (and indeed otherstakeholders) with a toolkit of information to support and guide decision making withrespect to management of this waste type.The key conclusions from this strategic guidance document are:• Compilation and review of the waste inventory shows that (at best estimate) the totalvolume of LLW and ILW / LLW cross-boundary pond furniture within the NDA estate isapproximately 14315m 3 . Approximately 96% of this waste is located at the Sellafieldsite. This waste inventory is predominantly stainless steel, with a smaller proportion ofmild steel and significantly smaller volumes of aluminium and lead. The majority of themild steel is surface coated with paint. This waste inventory is dominated by LLW. Inthe near term (i.e. in period up to 2030), it is anticipated that the majority of the wastewill be generated from retrievals at Magnox Ltd. sites, the RSRL Harwell site and thehigh hazard pond facilities (FGMSP and PFSP) at Sellafield.• A range of approaches are currently used for the waste management of pond furniture.These include size reduction, mechanical decontamination (surface washing, surfacewiping, UHP water jetting, shot-blasting and sponge-jet), metal melting and disposal(either direct / optimised disposal to LLWR or else interim storage pending disposal toGDF). Historically, there has been a reliance on disposal as the main managementapproach but there is increasing usage of routes better aligned with the wastemanagement hierarchy allowing for re-use and recycle, and diversion from disposal.• Significant efforts have been made in research and development allied to themanagement of pond furniture, particularly by Magnox Ltd. Examples of techniqueswhich have been trialled on pond furniture (or analogous wastes) include chemicaldecontamination with foam, DFD, DFDX, garnet blasting, metal milling and nitrocision.It is anticipated that successful R&D will transfer, over time, into routine usage wheresuccessful and appropriate to the waste.• Pond furniture is a complex waste type and is highly variable in physical, chemical andradiochemical characteristics within individual populations (i.e. within the same pond)and between sites / SLCs. Whilst a range of waste management approaches for pondfurniture have been identified, it should be noted that management of this waste type ischallenging for SLCs as a consequence of this variability.• A generic waste management decision making approach, utilising the principles of thewaste management hierarchy, has been defined for pond furniture. Early planning andoptioneering prior to retrievals is identified as good practice, to mitigate againstforeclosing options, and enabling collection and use of characterisation data. The valueA company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 56 of 58of characterisation as a mechanism to facilitate the underpinning of wasteclassifications and optioneering decisions is highlighted. Opportunities to down-classifywaste, re-use and recycle should be sought and exploited where practicable. Disposalshould be considered to be a worst case approach, and should only be pursued whereother options have been exhausted and where demonstrated to be BAT. Carefulconsideration should be given to the nature and management strategy for anysecondary wastes generated through the use of a treatment approach. In particular,generation of orphan wastes should be avoided.• A number of generic issues and barriers have been identified which make effectivemanagement of pond furniture more challenging for SLCs. These include the nature ofthe waste (i.e. the variability in the radiochemical characteristics of the waste within theinventory), the environment where the waste is stored (e.g. high dose environmentsmaking characterisation and waste management more dose intensive to operators, sorequiring more automated and remote systems for waste management), tensions withthe regulatory permitting regime and limited facilities, particularly for higher activitywastes. Opportunities have been identified to improve transfer of knowledge and toinvestigate the viability of centralised facilities for management of pond furniture.A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 57 of 589. References1. UK Strategy for the Management of Solid Low Level Radioactive Waste in the UnitedKingdom, Defra / DTI / Devolved Administrations, March 20072. <strong>Strategic</strong> BPEO for Metal Waste Management – Options Evaluation, P0090/TR/002,Studsvik UK, 20063. Review of <strong>Strategic</strong> Options for Metallic Waste, WMS-REP-NLWS/LLWR/25, Entec,Issue 1, 20114. The Nuclear Fuel Cycle: From Ore to Waste, Ed. PD Wilson, Oxford SciencePublications, Ed. 1, 19965. Spent fuel storage and transport cask decontamination and modification: An overviewof management requirements and applications based on practical experience, IAEA-TECDOC-1081, IAEA, 19996. Decommissioning Sellafield Ltds First Fuel Storage Pond, WMSYM 11125, T Calvin,Proceedings of WM2011 Feb 27 – Mar 3 2011 Phoenix AZ, 20117. UK Management of Solid Low Level Radioactive Waste from the Nuclear Industry:Low Level Waste <strong>Strategic</strong> Review, NLWS/LLWR/16, LLW Repository Ltd., 20118. The 2010 UK Radioactive Waste Inventory Main Report, DECC/NRWP10.002,NDA/004, 20119. Magnox Plan Summary: Magnox Lifetime Plan 2012, Magnox Ltd., Issue 1, 201210. The Way to a Cleaner Future Magnox Achievements in 2010/11, Magnox Ltd., Issue1, 201111. Research Sites Restoration Ltd Lifetime Plan Baseline – March 2011 Harwell SiteSummary, Research Sites Restoration Ltd., Issue 1, 201112. Cleaning Up Our Sites Harwell and Winfrith RSRL Achievements 2011-2012,Research Sites Restoration Ltd., Issue 1, 201213. Sellafield Plan, Sellafield Ltd., Issue 1, August 2011A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 58 of 5814. EARWG Waste Minimisation Good Practice Technology Database(http://www.rwbestpractice.co.uk/Main.aspx) worksheets:a. Foam Decontamination, Version 1, 2008b. Cryo-Cleaning, Version 1, 2007c. Mechanical Cutting (Hands On and Remote), Version 1, 2008d. Low Pressure Water Jets (Ultra) High Pressure Waste, Version 1, 2008e. Wiping / Scrubbing, Version 1, 2006f. Water flushing, Version 1, 2005g. Use of strong mineral acids, Version 1, 2008h. Melting, Version 1, 2004i. Use of abrasive cleaning, Version 1, 2008j. Metal milling, Version 1, 200515. A Study of the Management of Metal Waste Arisings from Decommissioning,RS/E&TS/GEN/RED/0081/06, WD/6-NRS13.3.3, R03-172(A), BNFL MagnoxGeneration, Issue A, 200416. UK Management of Solid Low Level Radioactive Waste from the Nuclear Industry:Metal Decontamination Study, LLW Repository Ltd., Issue 1, 200917. http://www.studsvik.com/en/Business-Areas/Waste-Treatment/Processing-of-Radioactive-Waste/Treatment-of-Metallic-Waste-in-the-UK/18. http://www.studsvik.com/en/Business-Areas/Waste-Treatment/Processing-of-Radioactive-Waste/Metallic-Waste-Treatment/19. http://www.siempelkamp.com20. Innovative water treatment and conditioning technologies at nuclear power plants,IAEA-TECDOC-1504, IAEA, 200621. The EPRI DFD Process, pp. 16-23, D Bradbury / G Elder / C Wood, RadwasteSolutions, Sep / Oct 2001 Edition22. Decontamination and recycling of radioactive material from retired components, SBushart / C Wood / D Bradbury / G Elder, Proceedings of the WM’07 Conference Feb25 – Mar 1 2007 Tucson AZ23. Policies and strategies for radioactive waste management, NW-G-1.1, IAEA, 2009A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED