Durability of Borosilicate Glass Compositions for the Immobilisation of the UK's Separated Plutonium Stocks

MRS Proceedings ◽

10.1557/proc-1107-429 ◽

2008 ◽

Vol 1107 ◽

Cited By ~ 1

Author(s):

Mike T. Harrison ◽

Charlie R. Scales

Keyword(s):

Borosilicate Glass ◽

Final Decision ◽

Long Term Storage ◽

Nuclear Decommissioning ◽

The Uk ◽

Fuel Reprocessing ◽

Tin Silicate ◽

Term Storage ◽

Glass Compositions

AbstractSeveral glass compositions are currently under investigation for immobilisation of the separated PuO2 that has been produced as a result of civil nuclear fuel reprocessing in the UK. Whilst a final decision on the fate of what ultimately will be over 100 tonnes of plutonium has yet to be made, all options for the disposition of this material are currently being investigated by Nexia Solutions Ltd on behalf of the Nuclear Decommissioning Authority (NDA).As one of the immobilisation options, vitrification in borosilicate glass could potentially provide a criticality-safe and stable waste form with durability suitable for long term storage and subsequent repository disposal. From an initial experimental survey of potential candidates, three borosilicate compositions were selected for a more detailed study of the waste loading and chemical durability: lanthanide borosilicate (LaBS), alkali tin silicate (ATS) and high-lanthanide alkali borosilicate (modified-MW). In these inactive tests, hafnium was used as the surrogate for plutonium. This paper describes a range of static leach tests that were undertaken in order to understand the overall durability of the waste forms, as well as the release rates of the Pusurrogate when compared to any neutrons poisons present in the glass. For the LaBS compositions it was found that the release rate of gadolinium was potentially slightly higher than that of hafnium, although both were as low as 10-5 to 10-6 g m2 day-1. The potential implications for long-term repository behaviour are discussed.

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Development of Borosilicate Glass Compositions for the Immobilisation of the UK's Separated Plutonium Stocks

MRS Proceedings ◽

10.1557/proc-1107-405 ◽

2008 ◽

Vol 1107 ◽

Cited By ~ 4

Author(s):

Mike T. Harrison ◽

Charlie R. Scales

Keyword(s):

Mixed Oxide Fuel ◽

Long Term Storage ◽

Nuclear Decommissioning ◽

Series Of Experiments ◽

The Uk ◽

Lanthanide Content ◽

Tin Silicate ◽

Selection Of ◽

Glass Compositions

AbstractThe UK inventory of separated civil plutonium is expected to exceed 100 tonnes by 2010. Whilst the majority of this could be used in the manufacture of MOx (Mixed Oxide) fuel in future power generation scenarios, options for the disposal of surplus plutonium are currently being investigated by Nexia Solutions Ltd on behalf of the UK's Nuclear Decommissioning Authority (NDA). One of the options being considered is immobilisation in a durable glass matrix followed by long term storage and subsequent final repository disposal.A preliminary experimental survey assessed a selection of potential glass systems on the basis of Pu-surrogate (cerium) loading, durability, and ease of processing. Following this, a number of borosilicate compositions have been taken forward into a more detailed investigation in order to fully qualify their potential for Pu-immobilisation. The selected compositions are lanthanide borosilicate (LaBS), alkali tin silicate (ATS) and high-lanthanide alkali borosilicate (modified-MW). For this second series of experiments, hafnium was selected as the Pu surrogate, and a study of the potential waste loading as a function of temperature for the three selected compositions is described in this paper. Furthermore, several variations of the LaBS composition were fabricated in order to investigate the effect of total lanthanide content on melting temperature. The benchmark of 10 wt% HfO2 incorporation is achievable for all three glasses with temperatures of 1200, 1300 and 1400 °C required for ATS, modified-MW and LaBS respectively.

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Release Behaviour of Sr-90 From Hydraulically Retrieved ILW Sludge

MRS Proceedings ◽

10.1557/proc-1107-613 ◽

2008 ◽

Vol 1107 ◽

Cited By ~ 1

Author(s):

J J Hastings

Keyword(s):

Ion Exchange ◽

Treatment Process ◽

Nuclear Industry ◽

Effluent Treatment ◽

The Novel ◽

Adsorption Behaviour ◽

Long Term Storage ◽

The Uk ◽

Term Storage

AbstractGlobally, the nuclear industry has a large number of legacy wastes that are stored in ponds, silos and tanks that are nearing the end of their design lifetime and hence said wastes need processing. In the UK there are significant quantities of radioactive sludge that have arisen from the corrosion of early Magnox fuel cans which have been stored underwater. As part of the present aggressive clean-up programme these materials will be retrieved, separated, processed and immobilised as dry waste forms for long-term storage. It is envisaged that hydraulic retrieval will be used for these ILW sludges resulting in some activity being released from the sludge phase to the process liquors challenging downstream ion exchange effluent treatment plants.In order to understand this challenge, experiments have been conducted on sludge in ILW storage ponds and during sludge transfer operations to study the activity released from said sludges. In particular the solubility, adsorption behaviour of Sr-90 is discussed and how this and other aspects of the sludge chemistry impact upon the ion exchange effluent treatment process. The novel methodologies employed to obtain this data is also discussed.

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Multienergy vector modelling of a Scottish Energy System: Transitions and technology implications

Proceedings of the Institution of Mechanical Engineers Part A Journal of Power and Energy ◽

10.1177/0957650917711820 ◽

2017 ◽

Vol 231 (6) ◽

pp. 580-589 ◽

Cited By ~ 1

Author(s):

Elizabeth Robertson ◽

Stuart Galloway

Keyword(s):

Distributed Generation ◽

Distribution System ◽

Carbon Sources ◽

Energy System ◽

Distributed Energy ◽

Long Term Storage ◽

Zero Carbon ◽

The Uk ◽

Term Storage

The Scottish Government’s commitment for 100% of electricity consumed in Scotland to be from renewable, zero-carbon sources by 2020 continues to drive change in the energy system alongside European and UK targets. The growth of renewables in Scotland is being seen at many scales including industrial, domestic and community generation. In these latter two cases, a transition from the current ‘top down’ energy distribution system to a newer approach is emerging. The work of this paper will look at a ‘bottom up’ view that sees community led distributed energy at its centre. This paper uses the modelling tool HESA to investigate high penetrations of distributed generation in the Angus Region of Scotland. Installations of distributed generation will follow Thousand Flowers transition pathway trajectory, which sees more than 50% of electricity demand being supplied by distributed generation by 2050. From this, insights around the technological and socio-political feasibility, consequences and implications of high penetrations of distributed generation in the UK energy system are presented. Results demonstrate the influence that system change will have on regional and local emission levels under four separate scenarios. It is shown that the penetration of distributed generation requires supplementary installations of reliable and long-term storage alongside utilisation of transmission and transportation infrastructures to maximise the potential of distributed generation and maximise whole system benefits. Importantly, there must be a level of co-ordination and support to realise a shift to a highly distributed energy future to ensure there is a strong economic case with a reliable policy backing.

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UK Government Web Continuity: Persisting Access through Aligning Infrastructures

International Journal of Digital Curation ◽

10.2218/ijdc.v4i1.82 ◽

2009 ◽

Vol 4 (1) ◽

pp. 107-124 ◽

Cited By ~ 3

Author(s):

Amanda Spencer ◽

John Sheridan ◽

David Thomas ◽

David Pullinger

Keyword(s):

Building Blocks ◽

Access To Information ◽

Parliamentary Debates ◽

Long Term Storage ◽

Wide Range ◽

The Government ◽

The Uk ◽

Term Storage ◽

The Web

Government's use of the Web in the UK is prolific and a wide range of services are now available though this channel. The government set out to address the problem that links from Hansard (the transcripts of Parliamentary debates) were not maintained over time and that therefore there was need for some long-term storage and stewardship of information, including maintaining access. Further investigation revealed that linking was key, not only in maintaining access to information, but also to the discovery of information. This resulted in a project that affects the entire government Web estate, with a solution leveraging the basic building blocks of the Internet (DNS) and the Web (HTTP and URIs) in a pragmatic way, to ensure that an infrastructure is in place to provide access to important information both now and in the future.

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Modelling of Moisture Movement in Wood during Outdoor Storage

Nonlinear Analysis Modelling and Control ◽

10.15388/na.2001.6.1.15210 ◽

2001 ◽

Vol 6 (2) ◽

pp. 3-14 ◽

Cited By ~ 23

Author(s):

R. Baronas ◽

F. Ivanauskas ◽

I. Juodeikienė ◽

A. Kajalavičius

Keyword(s):

Experimental Data ◽

Finite Difference ◽

Climatic Conditions ◽

Two Dimensional ◽

Moisture Movement ◽

Finite Difference Technique ◽

Long Term Storage ◽

Space Formulation ◽

Term Storage

A model of moisture movement in wood is presented in this paper in a two-dimensional-in-space formulation. The finite-difference technique has been used in order to obtain the solution of the problem. The model was applied to predict the moisture content in sawn boards from pine during long term storage under outdoor climatic conditions. The satisfactory agreement between the numerical solution and experimental data was obtained.

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