NDA's Direct Research Portfolios

Eden NE lead one of the consortia of Small and Medium-sized Enterprises (SMEs) to have won a place on the latest Integrated Waste Management and Site Decommissioning and Remediation framework as part of NDA's Direct Research Portfolio. Eden NE has previously worked with partners on this framework on many successful projects, demonstrating Eden NE's ability to co-ordinate subcontractors using a 'best athlete' approach to ensure excellent outcomes for our client. We have delivered high quality expert support to the NDAs research programme, which will give a vital input to the future safe and cost-effective decommissioning of the UK's nuclear legacy and to the remediation of the NDA sites in an environmentally sustainable manner.

Many projects undertaken have involved investigating and solving unique and difficult problems. For instance, one project involved exploring management options for radiologically contaminated mercury: including consideration of conditioning and treatment, packaging and final disposal. Another project involved looking at the acceptability of various waste management options with respect to the mixing of wastes, which is a sensitive topic because of the lack of extant legislation and guidance in this area. As such, this project involved running several workshops with regulators, waste service providers and site operators to work towards an industry consensus on acceptable approaches. Eden NE has also supported the NDA in reviewing packaging and transport issues for problematic wastes in the UK and investigated and suggesting solutions for securing the supply of suitable encapsulants for higher-activity wastes. Eden NE has also undertaken several projects related to legacy and remediation issues, including review of available administrative controls for the control of access to former nuclear sites when they have been delicensed and ensuring the protection of groundwater if contaminated structures are left in-situ as part of the nuclear site end state.

Our success in this framework contract has been recognised through our reappointment to the framework for the next three years, after a tendering competition, and Eden NE's appointment to NDA's sister framework under the Direct Research Portfolio on Spent Fuel and Nuclear Materials, again after a tendering competition.

Specific examples of the projects performed on the Integrated Waste Management and Site Decommissioning and Remediation framework follow.

• Informing the Development of a Strategic Approach for Encapsulation.

Eden NE are currently leading work for the NDA as a cross-industry initiative aimed to develop technical solutions for future supplies of the cement powders typically used to stabilise many kinds of low and intermediate level radioactive wastes. The work initially was centred on performing a two-phased desk-based review, to analyse current issues and subsequently outline options for managing any risks identified. Development of new technologies was also covered. The principal benefits of this work are focussed on improvement of understanding of issues, and identification of options that could be developed. The two work phases have now been complete, and third phase of work is in progress to establish and run a co-ordination group to provide technical advice and take forward identified options; the Encapsulation Coordination Group. Further information can be found below on the NDA website. Further information can be found below on the NDA website (https://www.gov.uk/government/case-studies/forward-planning-to-ensure-cement-supplies).

• Problematic Waste Packaging and Transport.

Eden NE has supported the NDA in reviewing packaging and transport issues for problematic wastes in the UK. Radioactive wastes for which no defined waste management route is either available or currently planned in detail, or for which existing solutions are sub-optimal, are known as 'problematic wastes' (also 'orphan wastes' or 'wastes requiring additional treatment'). Problematic wastes may include radioactive wastes that are "in scope", including Lower Activity Wastes (LAW) and Higher Activity Wastes (HAW). Solutions are needed for managing these wastes to enable optimised lifecycle management and to avoid prolonged storage in some cases where disposal routes exist. Eden NE engaged and worked with nuclear waste packaging and transport experts to identify packaging and transport solutions to the wastes involved, and in doing this ran a number of workshops to solicit contributions and advice from regulators, waste service providers and site operators.

• Management of Contaminated Mercury.

Eden NE supported the NDA in a research project exploring management options for radiologically contaminated mercury. A range of credible options that are applicable to sub-populations of radiologically contaminated mercury wastes were defined and were assessed against a range of factors using a pairwise comparison approach. This work suggested that the optimal approaches were likely to involve sulphidation (conversion to mercury sulphide) and subsequent conditioning by encapsulation and packaging for final disposal. The outcomes of this project are to be used in further work which will seek to establish an optimised cross-industry waste management approach for radiologically contaminated mercury.

• Blending, Mixing, Dilution or Averaging Radioactive Wastes.

Eden NE has supported the NDA in a project to develop principles to apply to mixing, blending and averaging radioactive waste. The objectives of the project were to develop a set of principles that can be applied to establish when dilution, mixing, blending and averaging of radioactive waste can legitimately be considered an optimal approach. The role involved performing review literatures, engagement with stakeholders, and ultimately producing guiding principles documentation. The key outputs included:

1. review of the use of the terms "blending", "mixing", "dilution" and "averaging" in both British and international regulatory and policy documents and relevant practices in the nuclear sector, practice in nuclear and non-nuclear sector and stakeholder understanding of the terms;
2. questionnaires and workshops with the NDA and key stakeholders, including regulators, and;
3. a detailed guiding principles document.