Post on 17-May-2018
Radioactive Waste Management Limited
Innovative approaches to optimise the management of higher activity radioactive wastes
Institute of Physics Nuclear Industry Group Ciara Walsh MInstP CPhys
Radioactive Waste Management Limited
Presentation Structure
Three sections:
• Geological disposal of UK higher activity radioactive waste (HAW), Government Policy, Finding a site.
• Disposability of HAW and industry challenges
• Innovative approaches to waste management
Radioactive Waste Management Limited
Radioactive Waste Management Limited • Mission
– Deliver a geological disposal facility and provide radioactive waste management solutions
• Created wholly-owned subsidiary Radioactive Waste
Management Limited (April 2014) – employ around 100 staff
– budget currently around £20 million per annum
– operate as ‘prospective’ Site Licence Company
– 11 Physicists
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Stages of waste management
Radioactive Waste Management Limited
Geological disposal
• Geological disposal isolates radioactive wastes from the surface environment and contains the radioactivity so that no harmful quantities reach the surface environment.
• The barriers that provide safety will be a combination of the radioactive waste and its packaging, components of the engineered disposal facility and the geological setting in which the facility is sited.
• The relative importance of the different barriers will depend on the chosen site and will change over time.
• Once a geological disposal facility is closed it no longer requires human intervention and avoids placing the burden of dealing with these wastes on future generations.
Radioactive Waste Management Limited
Implementing geological disposal
• A White Paper which sets out the UK
Government’s framework for managing higher activity radioactive waste;
• An ‘enabling’ document which addresses many issues that stakeholders have raised;
• Sets out a clear plan and timescales to address some remaining concerns and help communities participate.
Radioactive Waste Management Limited
Siting policy
• New policy framework: a number of initial actions followed by a process of working with communities.
• The initial actions include: – A national geological screening exercise – Amendments to national land-use planning arrangements for GDF and
boreholes – Providing greater clarity on how DECC/RWM will work with
communities • Still based on willingness of local communities to participate • Recognises importance of providing upfront information on issues
such as geology, socio-economic impacts and community investment
Radioactive Waste Management Limited
Siting process
Radioactive Waste Management Limited
Generic design and safety case
• Generic designs – Higher strength rocks – Lower strength sedimentary rocks – Evaporites
• Generic Disposal System Safety Case (DSSC)
– Addresses transport, construction and operation and long-term environmental safety issues
– Reviewed by regulators and CoRWM
• Waste package assessment and Letters of Compliance – Gives confidence that packages fit for disposal – Scrutinised by regulators
Radioactive Waste Management Limited
Disposability of HAW and industry challenges
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Our legacy – Magnox and other commercial reactors
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Our legacy - Research
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Our legacy - Sellafield
Radioactive Waste Management Limited
Interim storage and packaging for waste disposal • Government policy is geological disposal preceded by safe and
secure interim storage
• Significant investment spent on waste retrieval, packaging and storage
• Essential that packaged waste is suitable for eventual disposal
• Disposability assessment supports hazard reduction and reduces the risk of future re-work
• Operated by RWM, scrutinised by regulators
Radioactive Waste Management Limited
Relative contributions to waste package performance
Radioactive Waste Management Limited
Example container (3m3 Box)
Radioactive Waste Management Limited
Package handling at the GDF
Radioactive Waste Management Limited
Requirements on waste containers
• The integrity of the waste container shall be maintained for a period of 150 years and should be maintained for a period of 500 years following manufacture of the waste package
• How long has stainless steel been in existence? Are there any natural analogues? – After 500 years would you be willing to lift the 10 tonne container by
twistlocks at each corner?
Radioactive Waste Management Limited
Wasteform Requirements
Immobilisation Hazardous materials
Wasteform evolution
Mechanical and physical
properties Gas generation
physical immobilisation
pyrophoric materials
dimensional stability
mechanical strength
bulk gas generation
chemical containment
oxidising materials corrosion voidage flammable
gases
free liquids flammable liquids and
gases
radiation stability
mass-transport properties toxic gases
explosive materials leachability radioactive
gases
sealed containers homogeneity
thermal conductivity
Radioactive Waste Management Limited
Requirements on waste packages
• Under all credible accident scenarios the release of radionuclides and other hazardous materials from the waste package shall be low and predictable
• The waste package should exhibit progressive release behaviours within the range of all credible accident scenarios
Radioactive Waste Management Limited
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25 m drop- new requirement is 12 m
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1000°C, all engulfing for 1 hour (new
requirement is 30 minutes)
Radioactive Waste Management Limited
What do we mean by Innovation?
Organisation for Economic Co-operation and Development: – product innovations – process innovations – organisational innovations – marketing innovations
• Creativity: related to the production of novel and useful ideas • Innovation: creative ideas are actually implemented
• RWM or the wider industry can be an innovative through
exploitation/absorption of technology/processes etc. that may exist elsewhere
Radioactive Waste Management Limited
Innovation or improvement?
Radioactive Waste Management Limited
Innovation or improvement?
Radioactive Waste Management Limited
Time to implement
Radioactive Waste Management Limited
Intermediate Level Waste Arisings
Ability to create, innovate and implement (Move from TRL 1 to TRL 9)
Radioactive Waste Management Limited
Orphan/Problematic Wastes • Bulk Fines or Particulates
• Reactive Metals
• Pyrophoric Material
• Organic Ion Exchange Materials
• Inorganic Ion Exchange Material
• Radium/Thorium/Americium Contaminated Waste
• ILW Fuel
• Tritium Contaminated Waste
• Pyrochemical Wastes
• Halide-Based Fire Suppressant Powders
• Mercury Wastes
• Contaminated Bulk Oil
• Containerised Waste
• High Fissile/Moderator/Heat Waste
• Pressurised Waste
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• Material Contaminated with Oil
• Tritiated Oil
• Ventilation Filters
• Solvents
• Zinc Bromide
• Sludge
• Putrescible and Cellulose Waste
• Batteries
• Lead
• Isotope Cartridges
• Miscellaneous Activated Wastes
• Sealed Sources
• Graphite
• Asbestos
• Aqueous Liquids including Bottles of Liquid
• Physically Awkward Waste
Radioactive Waste Management Limited
Potential Treatment Technologies
• Literature searches for treatment technologies • Previous submissions to the RWM disposability assessment
process – an orphan on one site may be business as usual on another
• Potential waste treatment technologies available within supply chain
Output • A treatment matrix has been produced that maps the applicability
of treatment technologies against the generic orphan waste groups – where a treatment process is already available at an operating UK
nuclear facility – where the use of a treatment technology is being investigated.
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Radioactive Waste Management Limited
The challenge
How to enable cost effective and ALARP solutions for small volume waste streams?
• Design a waste container that:
– Has negligible releases in credible accident conditions – Has ‘excellent’ fire accident performance – Can be handled on sites with no additional infrastructure – Meets RWM specifications for disposable packages – Affordable
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Radioactive Waste Management Limited
Novel package for small volume wastes
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Vertical diaphragm (top 5mm,
bottom 10mm) Grout 10MPa
cylinder strength
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• Knockback ~85mm • 3m³ box suffer knockback deformations • Grout crushed and deformed at vicinity of impact • Diaphragm has deformed significantly • Inner box lid bolts have max. plastic strain of 2.8% • Inner box remained predominantly elastic • Inner box lid-body gap, ~0.4mm max; tortuous path for release due to lid spigot; no
significant change in internal volume; hence negligible release
FEA Analysis
Radioactive Waste Management Limited
Disposal of mercury wastes
Which forms are disposable?
Radioactive Waste Management Limited
£? Millions spent on R+D
What R+D was done and where is the information?
Radioactive Waste Management Limited
Encapsulation of fine particulate (RSRL Innovation)
Radioactive Waste Management Limited
Encapsulation of fine particulate (RSRL Innovation)
Radioactive Waste Management Limited
Decontamination (Sellafield HLW Plant)
Decontamination Agents
Radioactive Waste Management Limited
Learning from experience
• Use of organic polymers- offers advantages for specific waste types
• Many years of successful trials…
Radioactive Waste Management Limited
Learning from experience
And less than successful trials… • Trial pours of an epoxy resin, which had been formulated to have a
relatively low heat generation during curing, were made at the 100, 200 and 500 litre scales and resulted in peak measured temperatures of 49, 185 and >260°C respectively
We need to share the learning
Radioactive Waste Management Limited
Example opportunities in programme • Optimum packaging approach for disposal of decommissioning waste
arisings
• The use of surface decontamination agents
• Decay store short-lived ILW to allow disposal to near surface facilities
• Use of superplasticisers in encapsulated waste packages
• Development of an increased capacity reusable transport container
• Improved management of filters
• Optimised management of problematic wastes
• Use of neutron poisons/absorbers to increase limits on the fissile material content of ILW packages
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Radioactive Waste Management Limited
Key conclusions
• A lot of R+D exists – RWM hold a significant amount of information on historic industry work. Ask us!
• Innovation can be about asking the simple questions – Is a process needed (e.g. mercury) – How simple can I make the process (e.g. fine particulate) – Has it been done before (e.g. polymers) – How else could I achieve the aim (e.g. novel container)
• Fundamental research and innovation have a big role to play-
wastes will be generated for decades to come
Radioactive Waste Management Limited
Key conclusions
• The fundamental innovation occurring at the moment is that of
organisational innovation.
• Where new research is being undertaken, it tends to be collaborative across organisations, and to the benefit of the industry as a whole
• We are no longer operating in silos across the industry, and are actively sharing information
Radioactive Waste Management Limited
Questions?
Subscribe to receive the latest RWM updates at: www.nda.gov.uk/rwm ciara.walsh@nda.gov.uk 01925 802923 07909534945