Research in support of the 2011 environmental safety case for the Low Level Waste Repository

AbstractThis paper provides a summary of the research programme undertaken in support of the Low Level Waste Repository's 2011 environmental safety case (ESC). The programme has been developed, based on an understanding of safety issues and the requirements of the ESC. The research requirements to underpin the safety case have been identified by means of an auditable process, and subjected to scrutiny by both the regulators and a peer review group. Key research priorities for the future are identified.

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An Assessment of the Radiological Impact of Human Intrusion at the UK Low Level Waste Repository (LLWR)

ASME 2011 14th International Conference on Environmental Remediation and Radioactive Waste Management, Parts A and B ◽

10.1115/icem2011-59356 ◽

2011 ◽

Author(s):

Tim. Hicks ◽

Tamara Baldwin ◽

Richard Cummings ◽

Trevor Sumerling

Keyword(s):

Environmental Safety ◽

Assessment Model ◽

Disposal Site ◽

Barrier Materials ◽

Low Level ◽

Geotechnical Investigations ◽

Safety Case ◽

Waste Repository ◽

The Uk

The UK Low Level Waste Repository Ltd submitted an Environmental Safety Case for the disposal of low-level waste (LLW) to the Environment Agency on the 1st of May 2011. The Environmental Safety Case (ESC) presents a complete case for the environmental safety of the Low Level Waste Repository (LLWR) both during operations and in the long term (Cummings et al, in these proceedings). This includes an assessment of the long-term radiological safety of the facility, including an assessment of the potential consequences of human intrusion at the site. The human intrusion assessment is based on a cautiously realistic approach in defining intrusion cases and parameter values. A range of possible human intrusion events was considered based on present-day technologies and credible future uses of the site. This process resulted in the identification of geotechnical investigations, a housing development and a smallholding as requiring quantitative assessment. A particular feature of the site is that, because of its proximity to the coast and in view of expected global sea-level rise, it is vulnerable to coastal erosion. During such erosion, wastes and engineered barrier materials will be exposed, and could become targets for investigation or recovery. Therefore, human intrusion events have been included that are associated with such activities. A radiological assessment model has been developed to analyse the impacts of potential human intrusion at the site. A key feature of the model is the representation of the spatial layout of the disposal site, including the engineered cap design and the large-scale spatial heterogeneity of radionuclide concentrations within the repository. The model has been used to calculate the radiation dose to intruders and to others following intrusion at different times and at different locations across the site, for the each of the selected intrusion events, considering all relevant exposure modes. Potential doses due to radon and its daughters in buildings constructed on excavated spoil from the repository are a particular concern. Options for managing the emplacement of the radium-bearing waste packages with regard to human intrusion have been assessed. These calculations show that a managed waste emplacement strategy can ensure that calculated doses are consistent with regulatory guidance levels.

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Update on the Review of the LLWR 2011 Environmental Safety Case

Volume 1: Low/Intermediate-Level Radioactive Waste Management; Spent Fuel, Fissile Material, Transuranic and High-Level Radioactive Waste Management ◽

10.1115/icem2013-96036 ◽

2013 ◽

Author(s):

Richard Cummings ◽

Amy Huntington ◽

John Shevelan ◽

Andrew J. Baker ◽

Trevor Sumerling ◽

...

Keyword(s):

Environmental Safety ◽

Acceptance Criteria ◽

Low Level ◽

Additional Work ◽

Local Stakeholders ◽

Safety Case ◽

Waste Repository ◽

Environment Agency ◽

The Uk

The UK Low Level Waste Repository has submitted a fully revised Environmental Safety Case (ESC) to the Environment Agency for the continued operation of the site. The Environment Agency is reviewing the submission. As part of the review of the ESC, we have been engaging with the Environment Agency to answer questions and provide further clarification where required. Once the review is complete, LLWR will apply for a revised permit for the continued operation of the site. We are required by our current Permit to operate the site in accordance with the assumptions of the ESC. We have developed a process for the implementation and maintenance of the ESC as a ‘live’ safety case under formal change control, and the development of waste acceptance arrangements identified as necessary to ensure that the repository is operated in a safe and optimised way, consistent with the assumptions and results of the ESC. Engagement with waste consignors has been essential in the development of revised waste acceptance criteria. Additional work has also been carried out in the development of an Article 37 submission, presenting the ESC to local stakeholders and developing of waste emplacement strategies.

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Characterization and Assessment of the Groundwater Pathway for the Low Level Waste Repository, UK

ASME 2011 14th International Conference on Environmental Remediation and Radioactive Waste Management, Parts A and B ◽

10.1115/icem2011-59098 ◽

2011 ◽

Author(s):

Lee J. Hartley ◽

Martin James ◽

Peter Jackson ◽

Matt Couch ◽

John Shevelan

Keyword(s):

Radioactive Waste ◽

Groundwater Flow ◽

Environmental Safety ◽

Long Term Evolution ◽

Low Level ◽

Term Evolution ◽

Groundwater Flow Modelling ◽

Safety Case ◽

Waste Repository

The Low Level Waste Repository (LLWR) is the UK’s principal facility for the disposal of solid low-level radioactive waste and is operated by LLW Repository Limited. Presently, LLWR Ltd is establishing the long-term environmental safety of disposals of solid radioactive waste at the LLWR, through the submission of the 2011 Environmental Safety Case for the LLWR. This Environmental Safety Case addresses the Environment Agency Guidance on Requirements for Authorisation. Aspects of the submission consider improved vault design, closure design, and quantitative assessments. Each of these issues requires an understanding of the movement of water through the facility and the surrounding geology during operations and following facility closure. Groundwater flow modelling has been used extensively in support of the interpretation of field investigations, the development of the engineering design, and an assessment of the groundwater pathway as one of the major pathways by which contaminants may reach the environment. This paper describes these important aspects of the Environmental Safety Case. The geological environment in the region of the LLWR consists of Quaternary age deposits overlying older bedrock. The facility involves shallow excavations into the Quaternary deposits, originally for trenches, with disposals to a vault system beginning in 1988. In the post-closure phase these disposals are covered by a cap and surrounded by a cut-off wall to minimise the water flow around or through the waste. An innovative modelling methodology has been developed to represent the range of scales that have to be considered from the regional groundwater flow patterns over several kilometres, the scale of tens of metres around the immediate site area, and down to about 1 metre for details of flows within the repository itself in three dimensions. Detailed finite-element models of the flow through geological media and the engineered features are used to interpret site data and assess a credible set of post-closure situations and model cases. In the radiological assessment, a more simplified compartment model is used to assess uncertainties in hydrogeological properties and the long-term evolution of the engineered barriers. Together the approach provides flexible tools for understanding and assessing a comprehensive range of aspects including details of flows within the repository, dilution and migration in the external geology, the long-term evolution of the hydrogeological system, the implications of spatial variability and alternative geological models, and effects of uncertainties.

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The LLWR’s 2011 Environmental Safety Case

ASME 2011 14th International Conference on Environmental Remediation and Radioactive Waste Management, Parts A and B ◽

10.1115/icem2011-59135 ◽

2011 ◽

Author(s):

Richard Cummings ◽

Andrew J. Baker ◽

Trevor Sumerling ◽

John Shevelan ◽

Amy Huntington

Keyword(s):

Formal System ◽

Environmental Safety ◽

Management Control ◽

Careful Examination ◽

Supporting Evidence ◽

Gas Generation ◽

Low Level ◽

The Future ◽

Safety Case ◽

Level 2

The UK’s Low Level Waste Repository Ltd submitted an Environmental Safety Case (ESC) for the disposal of low-level waste to the Environment Agency on the 1st of May 2011. The ESC is a major submission that will decide the future use of the Repository and has major implications for the success of the UK’s LLW Strategy and decommissioning programme. This paper provides an overview of the work that has been carried out to support the submission. Key aspects of this ESC include: • detailed investigations of existing disposals, based on careful examination of existing records and other investigations, including interviews with former operational staff; • analysis of uncertainties in future disposals; • modelling of the biogeochemical evolution of the disposal system, which provides understanding of the evolution of pH, Eh and gas generation and thence underpinning for radionuclide releases in groundwater and gas; • development of a 3-D groundwater flow model, calibrated against observed heads and with a detailed representation of the engineered features; • analysis of coastal erosion and its impacts; • a major focus on optimisation based on detailed technical studies; • a conclusion that existing disposals do not require remediation; • the choice of a concrete vault design with permeable side walls designed to avoid bathtubbing after the end of management control; • a comprehensive set of assessment calculations, including thorough analysis of uncertainties, which demonstrate consistency with the Environment Agency’s risk and dose guidance levels; • revision of the LLWR’s WAC, based in part on the use of the ‘sum of fractions’ approach; • the use of a safety case document structure that emphasises key safety arguments in a Level 1 document and provides supporting evidence in a series of Level 2 documents; • the provision of a Level 2 document that describes in detail how each aspect of the regulatory guidance has been addressed. In the future, the 2011 ESC will be maintained using a formal system of change control. It will be used as a tool for decision making concerning the future development of the LLWR and waste acceptance.

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Characterisation of the Geology of the UK Low Level Waste Repository

ASME 2011 14th International Conference on Environmental Remediation and Radioactive Waste Management, Parts A and B ◽

10.1115/icem2011-59146 ◽

2011 ◽

Author(s):

John Shevelan ◽

Nicholas T. Smith

Keyword(s):

Site Investigation ◽

Environmental Safety ◽

Geological Model ◽

Hydrogeological Model ◽

Geological Interpretation ◽

Low Level ◽

Geological Models ◽

Waste Repository ◽

Site Characterisation ◽

The Uk

The UK Low Level Waste Repository Ltd (LLWR) submitted an Environmental Safety Case (ESC) for the disposal of low-level waste (LLW) to the UK Environment Agency on the 1st of May 2011. As part of the ESC, the LLWR have to demonstrate that a programme of site investigation and site characterisation has been carried out to provide the requisite information for the ESC and support facility design and construction. This paper explains the development of the site investigation programme and how the understanding of the geology of the site has developed. The geological environment in the region of the LLWR consists of Quaternary age deposits overlying older bedrock. The site has been subjected to a series of site investigation programmes from 1939 to the present day. The development of 3-D geological models was necessary to integrate data from boreholes, trial pits, geophysical investigations and beach exposures and data gained from site operations. The understanding of the geology has developed with each new set of data. Early simple interpretations from a few boreholes have been superseded by a series of more complex interpretations each incorporating the increasingly detailed observations. Initial attempts to develop a lithostratigraphic representation of the geology proved difficult. It was also difficult provide a clear link between the geology and the hydrogeology using a lithostratigraphic approach as required for the development of hydrogeological models. A lithofacies approach to characterising the geology was adopted in 2007, which has allowed the grouping of geological units with similar hydraulic properties and the development of a regional 3-D geological model. The 3-D geological model has been used as the framework for the development of a hydrogeological model for the site. The development of the 3-D geological models has been iterative. It was observed that there are differences between models developed using solely mathematical interpolation and those controlled by geological interpretation. The different representations of the geological information have been used to consider the effects of uncertainty in the geological interpretation in the hydrogeological modelling.

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Research and development for geological disposal of higher activity wastes: the role and expectations of the Environment Agency

Mineralogical Magazine ◽

10.1180/minmag.2011.075.4.2431 ◽

2011 ◽

Vol 75 (4) ◽

pp. 2431-2437

Author(s):

C. R. Cailes ◽

I. Barraclough ◽

R. E. Smith ◽

G. Thomson

Keyword(s):

Research And Development ◽

Research Programme ◽

Environmental Safety ◽

Nuclear Industry ◽

Geological Disposal ◽

England And Wales ◽

Disposal Facility ◽

Safety Case ◽

Environment Agency ◽

Regulatory Decisions

AbstractThe Environment Agency is the environmental regulator for the nuclear industry in England and Wales. We aim to ensure that any future Geological Disposal Facility (GDF) will meet our standards for protecting people and the environment during development, operation and following closure. We shall only grant an environmental permit for such a facility if the GDF developer submits an Environmental Safety Case (ESC) to the Environment Agency demonstrating that the proposed GDF will meet our standards. The ESC should be based on sound science and supported by appropriate research and development. The Environment Agency undertakes its own research programme to inform its regulatory decisions.

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Reuse of Low Specific Activity Material as Part of LLWR Design Optimisation

Volume 1: Low/Intermediate-Level Radioactive Waste Management; Spent Fuel, Fissile Material, Transuranic and High-Level Radioactive Waste Management ◽

10.1115/icem2013-96035 ◽

2013 ◽

Author(s):

Amy Huntington ◽

Richard Cummings ◽

John Shevelan ◽

Trevor Sumerling ◽

Andrew J. Baker

Keyword(s):

Specific Activity ◽

Environmental Safety ◽

Management Approach ◽

Low Level ◽

Safety Case ◽

Evaluation Stage ◽

Potential Impact ◽

And Control ◽

Term Management

A final cap will be emplaced over the disposed waste as part of the closure engineering for the UK’s Low Level Waste Repository (LLWR). Additional profiling material will be required above the waste to obtain the required landform. Consideration has been given to the potential opportunity to reuse Low Specific Activity Material (LSAM, defined as up to 200 Bq g−1) imported from other sites as a component of the necessary profiling material for the final repository cap. Justification of such a strategy would ultimately require a demonstration that the solution is optimal with respect to other options for the long-term management of such materials. The proposal is currently at the initial evaluation stage and seeks to establish how LSAM reuse within the cap could be achieved within the framework of an optimised safety case for the LLWR, should such a management approach be pursued. The key considerations include the following: The LSAM must provide the same engineering function as the remainder of the profiling material. The cap design must ensure efficient leachate collection, drainage and control for Low Level Waste (LLW) (and, by extension, LSAM) during the Period of Authorisation. In the longer term the engineering design must passively direct any accumulating waters preferentially away from surface water systems. An initial design has been developed that would allow the placement of around 220,000m3 of LSAM. The potential impact of the proposal has been assessed against the current Environmental Safety Case.

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Patients, clinicians and researchers working together to improve cardiovascular health: a qualitative study of barriers and priorities for patient-oriented research

BMJ Open ◽

10.1136/bmjopen-2019-031187 ◽

2020 ◽

Vol 10 (2) ◽

pp. e031187 ◽

Cited By ~ 3

Author(s):

Maria-Jose Santana ◽

Sandra Zelinsky ◽

Sadia Ahmed ◽

Chelsea Doktorchik ◽

Matthew James ◽

...

Keyword(s):

Health Research ◽

Heart Diseases ◽

Research Priorities ◽

Research Programme ◽

Advisory Council ◽

Future Research ◽

Prediction And Prevention ◽

Participatory Health Research ◽

Working Together ◽

Oriented Research

ObjectivesThe overall goal of this study is to identify priorities for cardiovascular (CV) health research that are important to patients and clinician-researchers. We brought together a group of CV patients and clinician-researchers new to patient-oriented research (POR), to build a multidisciplinary POR team and form an advisory committee for the Libin Cardiovascular Institute of Alberta.DesignThis qualitative POR used a participatory health research paradigm to work with participants in eliciting their priorities. Therefore, participants were involved in priority setting, and analysis of findings. Participants also developed a plan for continued engagement to support POR in CV health research.SettingLibin Cardiovascular Institute of Alberta, Cumming School of Medicine, University of Calgary, Canada.ParticipantsA total of 23 participants, including patients and family caregivers (n=12) and clinician-researchers (n=11).ResultsParticipants identified barriers and facilitators to POR in CV health (lack of awareness of POR and poor understanding on the role of patients) and 10 research priorities for improving CV health. The CV health research priorities include: (1) CV disease prediction and prevention, (2) access to CV care, (3) communication with providers, (4) use of eHealth technology, (5) patient experiences in healthcare, (6) patient engagement, (7) transitions and continuity of CV care, (8) integrated CV care, (9) development of structures for patient-to-patient support and (10) research on rare heart diseases.ConclusionsIn this study, research priorities were identified by patients and clinician-researchers working together to improve CV health. Future research programme and projects will be developed to address these priorities. A key output of this study is the creation of the patient advisory council that will provide support and will work with clinician-researchers to improve CV health.

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