An overview of gas research in support of the UK geological disposal programme

2012 ◽  
Vol 76 (8) ◽  
pp. 3271-3278 ◽  
Author(s):  
S. J. Williams
Keyword(s):  
Radioactive Waste ◽  
Waste Management ◽  
Gas Generation ◽  
Irreversible Damage ◽  
Geological Disposal ◽  
A Value ◽  
Nuclear Decommissioning ◽  
Disposal Facility ◽  
System Pressure ◽  
The Uk

AbstractGases will be generated in waste packages during their transport to a geological disposal facility (GDF), this generation will continue during GDF operations and after GDF closure. The range of gases produced will include flammable, radioactive and chemotoxic species. These must be managed to ensure safety during transport and operations, and the post-closure consequences need to be understood. The two primary post-closure gas issues for a GDF are the need for the system pressure to remain below a value at which irreversible damage to the engineered barrier system and host geology could occur, and the need to ensure that any flux of gas (in particular gaseous radionuclides) to the biosphere does not result in unacceptable risk. This paper provides an overview of the research of the Nuclear Decommissioning Authority, Radioactive Waste Management Directorate into gas generation and its migration from a GDF.

An overview of radionuclide behaviour research for the UK geological disposal programme

2012 ◽  
Vol 76 (8) ◽  
pp. 3373-3380 ◽  
Author(s):  
S. Vines ◽  
R. Beard
Keyword(s):  
Radioactive Waste ◽  
Waste Management ◽  
Waste Disposal ◽  
High Level Waste ◽  
Spent Fuel ◽  
Geological Disposal ◽  
Nuclear Decommissioning ◽  
Disposal Facility ◽  
The Uk ◽  
High Level

AbstractIn the UK, radioactive wastes currently planned for disposal in a geological disposal facility (GDF) are intermediate-level waste, some low-level waste and high-level waste. Disposal of other materials, including spent fuel, separated uranium and separated plutonium are also included in the planning of a GDF, if such materials are classified as wastes in the future. This paper gives an overview of the radionuclide behaviour research studies of the Nuclear Decommissioning Authority Radioactive Waste Management Directorate (NDA RWMD). The NDA RWMD's current understanding of the processes that control radionuclide behaviour in groundwater and how the engineered and natural barriers in a GDF would contain radionuclides is presented. Areas requiring further work are also identified.

Exploiting Synergies Between the UK and Japanese Geological Disposal Programmes

2010 ◽  
Author(s):  
Ellie Scourse ◽  
Hideki Kawamura ◽  
Ian G. McKinley
Keyword(s):  
Radioactive Waste ◽  
Waste Management ◽  
Geological Disposal ◽  
Nuclear Decommissioning ◽  
Novel Approach ◽  
Deep Geological Disposal ◽  
Safety Assessments ◽  
Site Characterisation ◽  
The Uk ◽  
High Level

The early ’80s UK programme for deep geological disposal of high-level radioactive waste was advanced and at the stage of characterising potential sites. When this project was put on hold in the mid ’80s, much expertise in this field was lost. In Japan R&D in the ’80s resulted in major generic safety assessments to demonstrate feasibility in the ’90s. This led to the establishment of NUMO (Nuclear Waste Management Organization of Japan) and the initiation of siting based on volunteerism. This novel approach required more flexible methodology and tools for site characterisation, repository design and safety assessment. NUMO and supporting R&D organisations in Japan have invested much time and effort preparing for volunteers but, unfortunately, no discussions with potential host communities have yet developed to the point where technical work is initiated. Presently, the UK is moving forward; with the NDA RWMD (Nuclear Decommissioning Agency Radioactive Waste Management Directorate) adopting a NUMO-style volunteering approach and a flexible design catalogue. Communities have already shown interest in volunteering. The situation is thus ideal for collaboration. The paper will expand on the opportunities for the UK and Japan to benefit from an active collaboration and discuss how this can be most efficiently implemented.

An introduction to geosphere research studies for the UK geological disposal programme

2012 ◽  
Vol 76 (8) ◽  
pp. 3105-3114 ◽  
Author(s):  
S. Norris
Keyword(s):  
Radioactive Waste ◽  
Waste Management ◽  
Research And Development ◽  
Specific Work ◽  
International Studies ◽  
Site Specific ◽  
Geological Disposal ◽  
Nuclear Decommissioning ◽  
The Uk ◽  
Research Studies

AbstractThis paper gives an overview of the geosphere research studies being undertaken by the Radioactive Waste Management Directorate (RWMD) of the Nuclear Decommissioning Authority. The approach of the RWMD in the current generic phase of the UK managing radioactive waste safely (MRWS) programme is to maintain an understanding of key processes and to carry out research and development into techniques so capability can be built. Although RWMD can demonstrate a general understanding of geosphere processes at this stage in the UK project, it is recognized that this will need to be made site-specific as the MRWS programme progresses. An understanding of the geosphere at the selected site(s) will be an important part of the future programme. Where possible, the RWMD will participate in international studies so that relevant site-based information can be accessed. In this way, the RWMD will be prepared for site-specific work in stage 5 of the MRWS process.

An overview of near-field evolution research in support of the UK geological disposal programme

2012 ◽  
Vol 76 (8) ◽  
pp. 2995-3001 ◽  
Author(s):  
T. M. Beattie ◽  
S. J. Williams
Keyword(s):  
Radioactive Waste ◽  
Host Rock ◽  
Near Field ◽  
Radioactive Decay ◽  
Geological Disposal ◽  
Nuclear Decommissioning ◽  
Disposal Facility ◽  
Engineered Barriers ◽  
The Uk

AbstractThe near field, together with the containment and isolation provided by the geosphere, contributes to the long-term safety provided by a geological disposal facility (GDF) after closure. The different engineered barriers can prevent or limit the release of radionuclides and their migration to the undisturbed host rock or geosphere and are expected to fulfil their post-closure safety functions for many thousands to hundreds of thousands of years. They will continue to contribute to containment after their eventual degradation when there would no longer be confidence that they would continue to fulfil all of their safety functions in their totality. By that time, significant radioactive decay will have occurred, substantially reducing the hazard associated with the wastes. Therefore, demonstration of long-term safety requires an understanding of the evolution of the engineered barriers and the consequences for the generic safety functions that the different barriers provide. This paper provides an overview of the research of the Nuclear Decommissioning Authority Radioactive Waste Management Directorate into the evolution of the near field of a GDF.

Implementation of a Geological Disposal Facility (GDF) in the UK by the NDA Radioactive Waste Management Directorate (RWMD): Coupled Modelling of Gas Generation and Multiphase Flow Between the Co-Located ILW/LLW and HLW/SF Components of a GDF

2009 ◽  
Author(s):  
Alex Bond ◽  
George Towler ◽  
Alan Paulley ◽  
Simon Norris
Keyword(s):  
Radioactive Waste ◽  
Multiphase Flow ◽  
White Paper ◽  
Phase Flow ◽  
Gas Generation ◽  
Geological Disposal ◽  
Disposal Facility ◽  
Multi Phase Flow ◽  
The Uk ◽  
Multi Phase

In June 2008 the UK government published a ‘White Paper’ as part of the “Managing Radioactive Waste Safety” (MRWS) programme to provide a framework for managing higher activity radioactive wastes in the long-term through geological disposal. The White Paper identifies that there are benefits to disposing all of the UK’s higher activity wastes (Low and Intermediate Level Waste (LLW and ILW), High Level Waste (HLW), Spent Fuel (SF), Uranium (U) and Plutonium (Pu)) at the same site, and this is currently the preferred option. It also notes that research will be required to support the detailed design and safety assessment in relation to any potentially detrimental interactions between the different modules. Different disposal system designs and associated Engineered Barrier Systems (EBS) will be required for these different waste types, i.e. ILW/LLW and HLW/SF. If declared as waste U would be disposed as ILW and Pu as HLW/SF. The Geological Disposal Facility (GDF) would therefore comprise two co-located modules (respectively for ILW/LLW and HLW/SF). A study has recently been undertaken by NDA RWMD to identify the key Thermo-Hydro-Mechanical-Chemical (THMC) interactions which might occur during both the operational and post-closure phases in order to assess the potential implications of co-location in a range of host rocks. This paper presents supporting modelling work used to help understand the potential interactions between the modules. A multi-phase flow and coupled gas generation model was used to help investigate the potential groundwater and gas fluxes between the modules, in particular considering the operational phase and resaturation behaviour of the different modules. These early phases are important because gas generation rates and hydraulic gradients will be at their maximum, and the pressure gradients associated with GDF operations will, at least initially, dominate over the background hydraulic gradient. The gas generation and multi-phase flow study considered a mudstone host rock in which gas pressurisation might significantly influence resaturation behaviour, or drive water from one module to the other. The results of the multiphase flow modelling show that although gas generation affects pressure recovery in the ILW/LLW module, the smaller size of the HLW/SF excavations compared with the ILW/LLW excavations, and the operational timings, mean that in general the groundwater pressure gradient in the GDF is from the HLW/SF module (higher pressure) to the ILW module (lower pressure). Transport of solutes from the HLW/SF module towards the ILW module is not expected to result in any deleterious interactions, indicating that hydraulic interactions during the resaturation period are unlikely to pose a fundamental barrier to co-location.

Application of Lifecycle Management to Design of the UK Geological Disposal Facility

2010 ◽  
Author(s):  
Philip G. P. Rendell ◽  
Henry J. P. O’Grady ◽  
Malcolm F. Currie
Keyword(s):  
Radioactive Waste ◽  
Engineering Design ◽  
Design Development ◽  
Geological Disposal ◽  
Requirements Definition ◽  
Nuclear Decommissioning ◽  
Disposal Facility ◽  
Staged Approach ◽  
The Uk ◽  
Five Phases

The Radioactive Waste Management Directorate (RWMD) of the United Kingdom’s (UK) Nuclear Decommissioning Authority (NDA) has been given the responsibility for delivery of a Geological Disposal Facility (GDF) for the UK’s higher activity wastes in accordance with government policy. As part of this process, the RWMD has developed a project lifecycle, which addresses the overall lifecycle of the GDF in terms of five phases, from Preparatory Studies through to Operation and finally Closure, and is developing a staged approach to engineering design. The Engineering Design Process is broken down into seven stages, encompassing option development, requirements definition and preliminary and detailed design through to “design development during closure”. Each stage finishes with a formally defined milestone (a “gate”) comprising a technical review and a specific set of engineering deliverables. This paper describes the background to the UK GDF development programme, the organisational issues associated with the RWMD’s evolving role, the relationship between the top-level UK Government’s Managing Radioactive Waste Safely programme [1] and the RWMD engineering lifecycle, the formal reviews, the milestones and the overall contribution this makes to RWMD organisational development and UK regulatory approval. It also describes some of the lessons learnt.

Sound science in geological disposal in the United Kingdom

2012 ◽  
Vol 76 (8) ◽  
pp. 2873-2879 ◽  
Author(s):  
C. J. Tweed
Keyword(s):  
United Kingdom ◽  
Radioactive Waste ◽  
Waste Management ◽  
Evidence Base ◽  
Scientific Data ◽  
Radioactive Waste Management ◽  
Geological Disposal ◽  
The United Kingdom ◽  
Nuclear Decommissioning ◽  
The Uk

AbstractThe safe implementation of geological disposal must be underpinned by sound science. This paper describes the approaches taken by the Nuclear Decommissioning Authority Radioactive Waste Management Directorate, the implementing body for geological disposal in the UK, to build an evidence base of scientific data and understanding which is robust to scrutiny and so provides confidence in the safety of geological disposal.

UKAEA, Dounreay: LLW Long Term Strategy — Developing the Options

2003 ◽  
Author(s):  
David Broughton
Keyword(s):  
Radioactive Waste ◽  
Waste Management ◽  
Corporate Strategy ◽  
Radioactive Waste Management ◽  
External Stakeholder ◽  
Nuclear Decommissioning ◽  
Site Restoration ◽  
The Uk ◽  
Scottish Executive

UKAEA’s mission at its Dounreay establishment in the north of Scotland is to restore the site so that it can be used for other purposes, with a minimal effect on the environment and requiring minimal attention by future generations. A Dounreay Site Restoration Plan (DSRP) has been produced. It sets out the decommissioning and radioactive waste management activities to restore the site within the next 60 years. Management of solid low level radioactive waste (LLW) that already exists, and that which will be produced as the DSRP progresses is an essential site restoration activity. Altogether around 150,000m3 (5.3Mft3) of untreated LLW could arise. This will then need to be treated, packaged and managed, the resulting volume being around 200,000m3 (7Mft3). A project to develop a long term strategy for managing all Dounreay’s existing and future LLW was initiated in 1999. The identification of complete solutions for management of LLW arising from the site restoration of Dounreay, an integrated reactor and reprocessing site, is novel in the UK. The full range of LLW will be encountered. UKAEA is progressing this specific project during a period when both responsibility and policy for UK decommissioning and radioactive waste management are evolving in the UK. At present, for most UK nuclear operators, there are no recognised routes for disposing of significant volumes of decommissioning LLW that has either lower or higher radioactivity than the levels set by BNFL for disposal at the UK national LLW disposal site at Drigg. A large project such as this has the potential to affect the environmental and social conditions that prevail in the area where it is implemented. Local society therefore has an interest in a project of this scale and scope, particularly as there could be a number of feasible solutions. UKAEA is progressing the project by following UK established practice of undertaking a Best Practicable Environmental Option (BPEO) study. UKAEA has no preconceptions of the outcome and is diligently not prejudging issues prematurely. The BPEO process draws experts and non-experts alike into the discussions and facilitates a structured analysis of the options. However to permit meaningful debate those options have to be at first generated, and secondly investigated. This has taken UKAEA two and a half years in technical assessment of options at a cost of around £23/4M. The options and issues have been investigated to the depth necessary for comparisons and valid judgements to be made within the context of the BPEO study. Further technical evaluation will be required on those options that eventually emerge as the BPEO. UKAEA corporate strategy for stakeholder participation in BPEO studies is laid out in “Restoring our Environment”, published in October 2002. This was developed by a joint approach between project managers, Corporate Communications, and discussion with the regulators, government departments and Scottish Executive. An Internal Stakeholder Panel was held in March 2003. The Panel was independently facilitated and recorded. Eight Panel members attended who provided a representative cross-section of people working on site. Two External Stakeholder Panels were held in Thurso at the end of May 2003. A Youth Stakeholder Panel was held at which three sixth form students from local High Schools gave their views on the options for managing Dounreay’s LLW. The agenda was arranged to maximise interactive discussion on those options and issues that the young people themselves considered important. The second External Stakeholder Panel was based on the Dounreay Local Liaison Committee. Additional participants were invited in acknowledgement of the wider issues involved. As the use of Drigg is an option two representatives from the Cumbrian local district committee attended. From all the knowledge and information acquired from both the technical and stakeholder programmes UKAEA will build up the objective line of argument that leads to the BPEO emerging. This will be the completion of this first stage of the project and is planned for achievement in March 2004. Once the BPEO has been identified the next stage will be to work up the applications for the authorisations that will be necessary to allow implementation of the BPEO. Any facilities needed will require planning permission from the appropriate planning authority. The planning application could be called in by a Minister of State or a planning inquiry convened. During this next stage attention will be paid to ensure all reports and submissions are consistent and compliant with regulations and possible future legal processes. Stakeholder dialogue will continue throughout this next stage moving on from disussion of options to the actual developments. The objective will be to resolve as many issues stakeholders might raise prior to the submissions of applications and prior to the regulators’ formal consultation procedures. This will allow early attention to those areas of concern. Beyond the submission of applications for authorisations it is unwise to speculate as nuclear decommissioning will be then organised in the UK in a different way. The Nuclear Decommissioning Authority will most probably be in overall control and, particularly for Dounreay, the Scottish Executive may have developed its policy for radioactive waste management in Scotland.

Development of an Engineering Design Process and Associated Systems and Procedures for a UK Geological Disposal Facility

2011 ◽  
Author(s):  
Philip Rendell ◽  
Henry O’Grady ◽  
Brendan Breen ◽  
Alastair Clark ◽  
Steve Reece
Keyword(s):  
Radioactive Waste ◽  
Engineering Design ◽  
Design Process ◽  
The Body ◽  
Requirements Management ◽  
Geological Disposal ◽  
Engineering Design Process ◽  
Disposal Facility ◽  
Uk Government ◽  
The Uk

In the United Kingdom the Nuclear Decommissioning Authority (NDA) has been charged with implementing Government policy for the long-term management of higher activity radioactive waste. The UK Government is leading a site selection process based on voluntarism and partnership with local communities interested in hosting such a facility and as set out in the ‘Managing Radioactive Waste Safely’ White Paper (2008). The NDA has set up the Radioactive Waste Management Directorate (RWMD) as the body responsible for planning, building and operating a geological disposal facility (GDF). RWMD will develop into a separately regulated Site Licence Company (SLC) responsible for the construction, operation and closure of the facility. RWMD will be the Design Authority for the GDF; requiring a formal process to ensure that the knowledge and integrity of the design is maintained. In 2010 RWMD published ‘Geological Disposal - Steps towards implementation’ which described the preparatory work that it is undertaking in planning the future work programme, and the phases of work needed to deliver the programme. RWMD has now developed a process for the design of the GDF to support this work. The engineering design process follows a staged approach, encompassing options development, requirements definition, and conceptual and detailed designs. Each stage finishes with a ‘stage gate’ comprising a technical review and a specific set of engineering deliverables. The process is intended to facilitate the development of the most appropriate design of GDF, and to support the higher level needs of both the project and the community engagement programmes. The process incorporates elements of good practices derived from other work programmes; including process mapping, issues and requirements management, and progressive design assurance. A set of design principles have been established, and supporting design guidance notes are being produced. In addition a requirements management system is being implemented for the identification, capture, analysis, update, verification, validation and acceptance of requirements for the GDF. This is to ensure that there are traceable links between requirements, and to identify and record the verification/validation of individual requirements. This paper describes the engineering design process and the supporting documents, systems and procedures. The paper addresses the relationship to the geological disposal programme timeline in ‘Geological Disposal - Steps towards implementation’ and, from there, to the UK Government ‘Managing Radioactive Waste Safely’ Programme. It also describes the next steps in the development of the design process, and some of the lessons learnt to date.

scholarly journals Thermal dimensioning to determine acceptable waste package loading and spatial configurations of heat-generating waste packages

2015 ◽  
Vol 79 (6) ◽  
pp. 1625-1632 ◽  
Author(s):  
Simon Myers ◽  
David Holton ◽  
Andrew Hoch
Keyword(s):  
Radioactive Waste ◽  
Waste Management ◽  
High Heat ◽  
Spent Fuel ◽  
Geological Disposal ◽  
Waste Package ◽  
Thermal Limits ◽  
Disposal Facility ◽  
Wide Range ◽  
Spatial Configurations

AbstractHeat-generating waste provides a number of additional technical challenges over and above those associated with the disposal of ILW. A priority area of work for Radioactive Waste Management (RWM) concerns the effect of heat on the engineered barrier system, and how this may be mitigated through the management of heat (thermal dimensioning) in a UK Geological Disposal Facility (GDF). The objective of thermal dimensioning is to provide a strategy to enable acceptable waste package loading and spatial configurations of the packages to be determined in order to enable high-heat generating waste to be successfully disposed in a GDF. An early focus of the work has been to develop a thermal modelling tool to support analyses of different combinations of package assumptions and other GDF factors, such as spacing of those packages, to assess the compliance with thermal limits. The approach has a capability to investigate quickly and efficiently the implications of a wide range of disposal concepts for the storage of spent fuel/HLW and the dimensions of a GDF. This study describes the approach taken to undertaking this work, which has included a robust appraisal of the key data (and the associated uncertainty); recent thermal dimensioning analysis has been performed to identify constraints on those disposal concepts.

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