The dissolution of simulant vitrified intermediate level nuclear waste in young cement water

AbstractIt is pertinent to the safety case for geological disposal in the UK that the behaviour of vitrified wastes in proximity to cementitious materials is understood. In this study, vitrified simulant intermediate level nuclear waste (ILW) was subject to dissolution in a synthetic cement water solution to simulate disposal conditions. Results show that the presence of alkali / alkaline earth elements in the cementitious solution can be favourable, at least in the short-term, leading to lower dissolution rates associated with incorporation of these elements into the altered layer of the glass.

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Opportunities for Research in the UK for Decommissioning and Disposal

MRS Proceedings ◽

10.1557/proc-1107-15 ◽

2008 ◽

Vol 1107 ◽

Author(s):

Neil Smart

Keyword(s):

Nuclear Waste ◽

Life Time ◽

Short Term ◽

Site License ◽

Technology Gaps ◽

The Uk ◽

High Level ◽

Technical Solutions ◽

Programme Delivery ◽

Fund Research

AbstractThe NDA remit as set out within the Energy Act includes – “promote, and where necessary fund, research relevant to nuclear clean up”. The NDA need to underpin delivery and / or accelerate programmes to fulfil the overall mission and technical underpinning of these activities is critical. In this paper we will present consideration of the investment required in nuclear waste Research and Development.Firstly, NDA set the requirement for nuclear sites to write down within the Life Time Plans (LTP), at a high level, the proposed technical baseline underpinning the LTP activities; furthermore we required technology gaps / opportunities in the technical baselines to be outlined in a R&D requirements section to the LTP. Criteria were established to categorise the R&D in three areas:“needs” - those development activities needed to underpin the proposed technical solutions“risks” – those activities required to reduce / eliminate key risks to the proposed technical solutions“opportunities” – innovations / changes to the technical baselinesThe purpose of production of the technical baselines and underpinning R&D requirements is to establish an auditable trail through the LTP from programme components into how the programme will be delivered.NDA believes the production of the technical baselines and R&D requirements will be of benefit to the Site License Companies (SLC) in terms of ensuring a focus on overall programme delivery and not just short term activities. Furthermore, we can ensure that investment in technology is targeted at priority areas, with common issues and requirements identified and solutions on a broader scale will be achievable.

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The potential impact of anaerobic microbial metabolism during the geological disposal of intermediate-level waste

Mineralogical Magazine ◽

10.1180/minmag.2012.076.8.39 ◽

2012 ◽

Vol 76 (8) ◽

pp. 3261-3270 ◽

Cited By ~ 43

Author(s):

A. Rizoulis ◽

H. M. Steele ◽

K. Morris ◽

J. R. Lloyd

Keyword(s):

Nuclear Waste ◽

Microbial Metabolism ◽

Electron Acceptors ◽

Intermediate Level ◽

Geological Disposal ◽

Ph Values ◽

Redox Active ◽

Safety Case ◽

Potential Impact ◽

Ph Range

AbstractMicrobial metabolism has the potential to control the biogeochemistry of redox-active radionuclides in a range of geodisposal scenarios. In this study, sediments from a high pH lime workings site were incubated under carefully controlled anaerobic conditions, at a range of alkali pH values with added electron donors and electron acceptors, to explore the limits and rates of bioreduction in a sediment system analogous to intermediate-level nuclear waste. There was a clear succession in the utilization of electron acceptors (in the order nitrate > Fe(III)-citrate > Fe(III) oxyhydroxide > sulfate), in accordance with calculated free energy yields and Eh values over the pH range 10–12. The rate and extent of bioreduction decreased at higher pH, with an upper limit for the processes studied at pH 12. The biochemical limits for such processes are discussed, alongside the potential impact of such forms of microbial metabolism on the solubility of a range of redox active radionuclides that will feature heavily in the safety case for the geological disposal of intermediate-level nuclear waste.

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Modelling of the Evolution of Porewater Chemistry in a Cementitious Repository

MRS Proceedings ◽

10.1557/proc-176-175 ◽

1989 ◽

Vol 176 ◽

Author(s):

A. Haworth ◽

S.M. Sharland ◽

C.J. Tweed

Keyword(s):

Nuclear Waste ◽

Transport Model ◽

Near Field ◽

Intermediate Level ◽

Current Concept ◽

Release Rates ◽

Chemistry Transport Model ◽

Porewater Chemistry ◽

The Uk ◽

Cement Formulation

ABSTRACTThe current concept for disposal of low- or intermediate-level nuclear waste in the UK includes a largely cementitious backfill. An important factor in determining nuclide release rates from the repository is the pH in the near-field. In this paper, we describe development of a coupled chemistry/transport model of cement degradation and its application in determining the evolution of the chemistry within the repository. In particular, the effect of the cement formulation and interaction with groundwater species on the evolution of the pH is examined. The model is sufficiently flexible to consider a number of different repository scenarios.

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Alteration of vitrified intermediate level nuclear waste in alkaline media: effects of cementitious materials, pH and temperature

RSC Advances ◽

10.1039/c8ra05227a ◽

2018 ◽

Vol 8 (66) ◽

pp. 37665-37680 ◽

Cited By ~ 2

Author(s):

Tomo Suzuki-Muresan ◽

A. Abdelouas ◽

C. Landesman ◽

A. Ait-Chaou ◽

Y. El Mendili ◽

...

Keyword(s):

Cement Paste ◽

Nuclear Waste ◽

Media Effects ◽

Cementitious Materials ◽

Intermediate Level ◽

Alkaline Media ◽

Hardened Cement ◽

Hardened Cement Paste

Alteration experiments involving intermediate level nuclear waste (ILW) glass in contact with hardened cement paste (HCP) were performed to assess its behavior under simulated repository conditions.

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The Dynamics of the Short-Term Interest Rate in the UK

SSRN Electronic Journal ◽

10.2139/ssrn.670503 ◽

2005 ◽

Author(s):

Diether W. Beuermann ◽

Antonios Antoniou ◽

Alejandro Bernales

Keyword(s):

Interest Rate ◽

Short Term ◽

The Uk

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Specialist infantry and defence engagement

BMJ Military Health ◽

10.1136/bmjmilitary-2020-001455 ◽

2020 ◽

pp. bmjmilitary-2020-001455 ◽

Cited By ~ 1

Author(s):

Jonathan Blair Thomas Herron ◽

K M Heil ◽

D Reid

Keyword(s):

Armed Forces ◽

Short Term ◽

The Future ◽

Uk Government ◽

The Uk ◽

Insight Into

In 2015, the UK government published the National Strategic Defence and Security Review (SDSR) 2015, which laid out their vision for the future roles and structure of the UK Armed Forces. SDSR 2015 envisaged making broader use of the Armed Forces to support missions other than warfighting. One element of this would be to increase the scale and scope of defence engagement (DE) activities that the UK conducts overseas. DE activities traditionally involve the use of personnel and assets to help prevent conflict, build stability and gain influence with partner nations as part of a short-term training teams. This paper aimed to give an overview of the Specialist Infantry Group and its role in UK DE. It will explore the reasons why the SDSR 2015 recommended their formation as well as an insight into future tasks.

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THE VALUE OF ROBUST STATISTICAL FORECASTS IN THE COVID-19 PANDEMIC

National Institute Economic Review ◽

10.1017/nie.2021.9 ◽

2021 ◽

Vol 256 ◽

pp. 19-43

Author(s):

Jennifer L. Castle ◽

Jurgen A. Doornik ◽

David F. Hendry

Keyword(s):

Structural Change ◽

Measurement Errors ◽

Epidemiological Models ◽

Short Term ◽

Data Measurement ◽

Policy Interventions ◽

Changing Trends ◽

Technological Advances ◽

The Difference ◽

The Uk

The Covid-19 pandemic has put forecasting under the spotlight, pitting epidemiological models against extrapolative time-series devices. We have been producing real-time short-term forecasts of confirmed cases and deaths using robust statistical models since 20 March 2020. The forecasts are adaptive to abrupt structural change, a major feature of the pandemic data due to data measurement errors, definitional and testing changes, policy interventions, technological advances and rapidly changing trends. The pandemic has also led to abrupt structural change in macroeconomic outcomes. Using the same methods, we forecast aggregate UK unemployment over the pandemic. The forecasts rapidly adapt to the employment policies implemented when the UK entered the first lockdown. The difference between our statistical and theory based forecasts provides a measure of the effect of furlough policies on stabilising unemployment, establishing useful scenarios had furlough policies not been implemented.

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First-of-a-kind muography for nuclear waste characterization

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2018.0048 ◽

2018 ◽

Vol 377 (2137) ◽

pp. 20180048 ◽

Cited By ~ 5

Author(s):

David Mahon ◽

Anthony Clarkson ◽

Simon Gardner ◽

David Ireland ◽

Ramsey Jebali ◽

...

Keyword(s):

Nuclear Waste ◽

Imaging System ◽

Academic Research ◽

Cosmic Ray ◽

Laboratory Facility ◽

Waste Container ◽

High Resolution Images ◽

And Performance ◽

The Uk ◽

The University

In the last decade, there has been a surge in the number of academic research groups and commercial companies exploiting naturally occurring cosmic-ray muons for imaging purposes in a range of industrial and geological applications. Since 2009, researchers at the University of Glasgow and the UK National Nuclear Laboratory (NNL) have pioneered this technique for the characterization of shielded nuclear waste containers with significant investment from the UK Nuclear Decommissioning Authority and Sellafield Ltd. Lynkeos Technology Ltd. was formed in 2016 to commercialize the Muon Imaging System (MIS) technology that resulted from this industry-funded academic research. The design, construction and performance of the Lynkeos MIS is presented along with first experimental and commercial results. The high-resolution images include the identification of small fragments of uranium within a surrogate 500-litre intermediate level waste container and metal inclusions within thermally treated GeoMelt® R&D Product Samples. The latter of these are from Lynkeos' first commercial contract with the UK National Nuclear Laboratory. The Lynkeos MIS will be deployed at the NNL Central Laboratory facility on the Sellafield site in Summer 2018 where it will embark upon a series of industry trials. This article is part of the Theo Murphy meeting issue ‘Cosmic-ray muography’.

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