Radwaste management: ILW
New UK radwaste strategy creates a market for diverting LLW from disposal13 September 2011
Just as NDA licensee EnergySolutions lobbied the UK government to change its approach on intermediate waste storage, another public-private initiative has changed the culture, and the industry, of low level waste (LLW) disposal in the UK. By Penny Hitchin
Less than 12 months ago the UK’s Nuclear Decommissioning Authority launched a low level radioactive waste strategy based on reducing the amount of solid waste for disposal. Techniques to reduce LLW disposal include metal treatment, combustion and diverting very low level waste (VLWW) to landfill.
Responsibility for managing this strategy rests with Low Level Waste Repository (LLWR) Ltd. This organisation, which also operates the UK’s nearly-full site at Drigg in West Cumbria, was the recipient of the first parent body organisation private contract offered by the UK government’s Nuclear Decommissioning Authority. In April 2008, the contract to run LLWR was won by the consortium UK Nuclear Waste Management Ltd (UKNWM), made up of URS Washington, Studsvik, Areva and Serco Assurance.
Dick Raaz, LLWR managing director, told the LLW customer forum annual meeting on 12 May in Cumbria that the last 12 months has seen a staggering rate of change in dealing with low level waste. “It has been a fantastic year,” he said adding that waste shipments to LLWR are down by 25 percent, due to new alternative LLW treatment routes opening up under the new national strategy. “If you can do it for LLW, you can do it for ILW and HLW,” he said. (At the same time, a new repository at Drigg, the highly-engineered Vault 9, opened a year ago and has eased capacity issues for the time being.)
Still, adopting an integrated national approach has reduced the UK ‘LLW Nuclear Provision’ (estimated liability over its lifetime) from £9.8 billion in 2008 to £7.4 billion in 2011.
But it is not only the public who benefits.
LLWR has developed service arrangements for metallic waste and combustible waste treatment. It has contracts in place with the supply chain to deal with shipments of low level waste from its customers, mainly nuclear generating sites undergoing decommissioning, but also medical, marine and defence organisations.
LLWR has contracts with three service providers under the Metallic Waste Treatment Service Framework. The companies holding the frameworks vie for contracts in mini-competitions to handle specific, characterised consignments. The providers are:
- EnergySolutions, which uses metal treatment facilities at Bear Creek (Oak Ridge, Tennessee, USA); Inutec (Winfrith, UK) and Siempelkamp GmbH (Krefeld, Germany)
- Nuvia, which uses the treatment facility at Socodei (Centraco, France)
- Studsvik, which uses the treatment facilities at Studsvik Metal Recycling Facility (Workington, UK) and Studsvik AB (Nyköping, Sweden).
In the financial year 2010/11, 1000 tons of metal was treated.
David Ferguson of EnergySolutions told NEI that in the year ended April 2011 his company processed 160 tonnes of LLW metal under framework contracts and has a further 50 tonnes is awaiting export licence. The metal (all low-activity) was shipped to Siempelkamp in Germany where it was smelted. The radioactive slag (which has been volume reduced by around 95 percent) is returned to the UK for disposal at LLWR. In Germany the free-release metal is recycled by Siempelkamp into GNS Yellow Boxes. Ultimately, he said, it might be possible for a site to send its radioactive metal to Siempelkamp and receive it back as Yellow Boxes. No metal has been sent to Bear Creek this year; that site has higher acceptance criteria. Other contracts were awarded to Studsvik for treatment at Lillyhall in Cumbria and to Nuvia for treatment at the Socodei facility in France.
In addition, an environmental permitting exception made in January 2011 has paved the way for combustion of LLW in the UK. The new combustible waste treatment service framework has four contractors:
- Abbot Nuclear Consulting, using the Tradebe (Fawley, UK) incinerator
- Nuvia, using the Socodei (Centraco, France) treatment facility
- EnergySolutions, using Bear Creek (Oak Ridge, Tennessee, USA); Belgoprocess (Mol-Dressel, Belgium); Inutec (Winfrith, UK) and Grundon (Colnbrook, UK)
- Studsvik, using treatment facilities at Studsvik AB (Nyköping, Sweden) and Tradebe (Fawley, UK)
As of May, four consignments had been despatched in 2011 using three of the routes.
Other forthcoming areas of development in the integrated approach to LLW management are transport, logistics and packaging. LLWR Ltd is developing three new packages to improve efficiency and to maintain as much capacity as possible in the repository.
First, the traditional half-height ISO container will be replaced by a range of more efficient designs optimised for different uses. Transport of segregated waste between consignors and treatment facilities will employ a reusable half height ISO ‘TC-02’ (see also p37). This will allow customers to place segregated waste into smaller containers, usually located near to the point that waste is generated. Once filled, the smaller containers can be secured to a stillage which can be placed into the
TC-02 and secured. The loaded TC-02 is then sent to the treatment facility where the stillage is lifted out and the waste is prepared for processing. LLWR say that this approach will improve waste segregation, ease the consignment process and avoid difficulties of reuse associated with the existing half-height ISO container.
Second, while the existing disposal container has an external volume of 20 m3, it holds less than 16 m3. A new single-use disposal container, designated DL-01, is under development. DL-O1 will have an external volume of 15m3 but the space available for waste will be around 14.5 m3.
Third, LLWR is developing a system to transport disposable soft-sided inner packages, similar to those used in the USA and elsewhere. The inner container will be placed in the disposal site, and the outer transport container returned to the waste generation site for further shipments.
Other areas under development include a development of a very low level waste (VLLW) service, due in September 2011; developing waste characterisation services for customers; integrating transport services and making best use of existing assets.
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