Innovative approaches to optimise the management of … · the management of higher activity...

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


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 • 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

Radioactive Waste Management Limited 4

Stages of waste management


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.


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.


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


Siting process


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


Disposability of HAW and industry challenges


Our legacy – Magnox and other commercial reactors


Our legacy - Research


Our legacy - Sellafield


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


Relative contributions to waste package performance


Example container (3m3 Box)


Package handling at the GDF


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?


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


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


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25 m drop- new requirement is 12 m


1000°C, all engulfing for 1 hour (new

requirement is 30 minutes)


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


Innovation or improvement?


Time to implement


Intermediate Level Waste Arisings

Ability to create, innovate and implement (Move from TRL 1 to TRL 9)


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


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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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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Novel package for small volume wastes

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Vertical diaphragm (top 5mm,

bottom 10mm) Grout 10MPa

cylinder strength


• 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


Disposal of mercury wastes

Which forms are disposable?


£? Millions spent on R+D

What R+D was done and where is the information?


Encapsulation of fine particulate (RSRL Innovation)


Decontamination (Sellafield HLW Plant)

Decontamination Agents


Learning from experience

• Use of organic polymers- offers advantages for specific waste types

• Many years of successful trials…


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


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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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


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


Questions?

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