NDA PhD Bursary Waste Packaging and Storage Theme

Richard Guppy, RWM Ltd

Sean Morgan, Sellafield Ltd

17th September 2015

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NWDRF Waste Packaging and Storage Working Group Activities

• Objectives of the WPSWG:– Establish and maintain a cross-industry technical community with

an interest and expertise in the conditioning and packaging of nuclear waste

– To deliver a targeted programme of research. • Common issues, opportunities and (technical) risks are

identified and research proposals developed to address them, to enable the improved delivery of the NDA mission.

– Share information and experience, leading to more effective programmes within individual organisations, and improved technical co-ordination across the industry.

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NWDRF Waste Packaging and Storage Working Group Activities

• Meetings 3 times a year, all members plus:– Institutions invited to host– Invited speakers

• Review NDA PhD bursary and other PhD initiatives• Produce and review DRPs – 21 DRPs. From databases to

alternative treatment matrices• Cross industry learning – Security of supply of materials, LFE• Members:

– Site Licence Companies (SLCs); DSRL, RSRL, Magnox, LLWR, RWM

– Regulators; EA/NWAT, ONR, SEPA– NDA– Others; MoD, AWE, EdF

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PhD call waste packaging and storage topics

1. Technologies for waste package monitoring during surface storage

2. Performance of metal containers not made from stainless steel

3. Methods of reducing the cost of waste packages

4. Methods for more efficient application of the waste hierarchy principles of reuse and recycle

5. Development of alternative treatment technologies to improve packaging processes

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Topic 1: Package monitoring during storage

• Packages of Higher Activity Wastes manufactured in advance of availability of a Geological Disposal Facility (GDF), or manufactured for surface storage in Scotland, are likely to require long-term storage;

• Even in a GDF, packages may require monitoring, for example prior to final closure;

• Monitoring of package integrity and ageing processes is necessary to confirm continued suitability for storage and ideally also to track any observable ageing trends;

• Existing HAW waste packages are manufactured using metal containers (stainless steels, ductile cast iron) or concrete containers, and where waste is encapsulated are mostly based on cement encapsulation, supercompaction or vitrification;

• PhD studies concerned with application of in-cell monitoring technologies would be relevant to this topic.

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Topic 2: Performance of metal containers not manufactured from stainless steel

• Most HAW waste packages are manufactured using stainless steel containers, but other metals could be used if specific performance requirements can be met;

• Ductile cast iron, in thick sections, is an existing example of an alternative, but another example could be carbon steel;

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Performance of metal containers not manufactured from stainless steel

• In historical options studies, other metals have not been favoured for various reasons (e.g. on grounds of cost, longevity, mechanical properties, etc). Can other metal containers be enhanced, or confidence in them improved, to meet performance requirements?

• PhD studies that would assist development of alternative metal containers are sought.

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Topic 3: Reducing the cost of waste packages

• Waste existing and currently proposed types of packages for HAW, the containers and wasteforms, are expensive to manufacture;

• Monitoring requirements during storage also have a cost; • Can the cost of these packages be reduced, for example by

application of new materials, fabrications methods, reduced monitoring requirements, etc?

• PhD studies that would assist methods of reducing the cost of waste packages are sought.

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Topic 4: Applying the waste hierarchy

• Development of methods to more efficiently apply the waste hierarchy principles of reuse and recycle. This may include efficient methods of sorting and segregation of wastes, decontamination, and reuse or recycling processes. Typically consider contaminated waste materials such as metals, concrete and soil.

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Applying the waste hierarchy

• The nuclear industry used considerable amount of steel in construction of chemical facilities and reactors. Could this be decontaminated and reused?– E.g. Plutonium contaminated steels may be decontaminated by

remelting, where Pu will readily partition to the metallurgical slag• Recycle of wastes:

– Large volumes of stainless steel, copper, nimonic alloys– Large volumes of concrete

• Sorting and segregation:– In the past, wastes were often mixed without thought of recovery.

Being able to sort and segregate by material and/or radioactivity may provide more efficient packing and reduce cost.

• Decontamination to reduce activity of the bulk material

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Topic 5: Alternative waste treatment technologies (1)

• Very diverse wastes – chemically, physically, radialogically and mixtures there of. Volumes vary from site to site.

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• Cement encapsulation the baseline but some wastes not so amenable to cements:• Amphoteric metals such as Al, U• Oils and organic materials

• New processes could reduce volumes/numbers of waste packages and wasteform performance

Alternative waste treatment technologies (2)

• Recycle of wastes:– Large volumes of stainless steel, copper, nimonic alloys– Large volumes of concrete

• Some sites have small volumes of waste, typically “hard to treat” via conventional routes:– Mercury, oils (organic and synthetic), resins, sludges etc.– Mobile or high throughput technologies?

• Any new product needs to be verified for performance• Mixed waste is often poorly characterised

– Processes insensitive to the input?– Methods of easily sorting and segregating wastes?

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