EC FORGE project: updated consideration of gas generation and migration in the safety case

2014 ◽  
Vol 415 (1) ◽  
pp. 241-258 ◽  
Author(s):  
Simon Norris
Keyword(s):  
Gas Generation ◽  
Safety Case ◽  
And Migration

The LLWR’s 2011 Environmental Safety Case

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.

ORIGIN OF PETROLEUM IN THE BOWEN AND SURAT BASINS: GEOCHEMISTRY REVISITED

1995 ◽  
Vol 35 (1) ◽  
pp. 579 ◽  
Author(s):  
C. J. Boreham
Keyword(s):  
Vitrinite Reflectance ◽  
Stable Carbon Isotope ◽  
Isotope Analysis ◽  
Source Rocks ◽  
Gas Generation ◽  
Delta Plain ◽  
The North ◽  
Biomarker Analysis ◽  
And Migration ◽  
A Minor

A detailed regional geochemical study of over 70 oils and condensates, eleven natural gases and over a hundred core samples from potential source rocks enable resolution of the generation and migration history of petroleum in the Bowen and Surat Basins. Biomarker analysis confirms a pre-Jurassic source for the petroleum. Stable carbon-isotope analysis further indicated a Permian-sourced petroleum and was able to differentiate a very minor and localised Triassic source contribution. The dominant source for the petroleum is terrestrial land plants as well as a minor contribution from bacteria and marine algae. In the north, Late Permian lower delta plain and alluvial Permian coals show the higher liquid potential compared with upper delta plain facies, while in the Taroom Trough, coals in the Blackwater Group have the highest liquid potential compared with mudrocks of the Blackwater Group, and sediments of the Back Creek Group. Initial liquid expulsion from the source rock occurred at vitrinite reflectance (Ro) of 0.65-0.7 per cent and continued to Ro of 1.05 per cent. This was followed by the main phase of gas generation between 1.05 per cent

scholarly journals Influence of ambience temperature and operational-constructive parameters on landfill gas generation: Case study Novi Sad

2010 ◽  
Vol 14 (2) ◽  
pp. 555-564
Author(s):  
Goran Vujic ◽  
Nebojsa Jovicic ◽  
Maja Petrovic-Djurovic ◽  
Dejan Ubavin ◽  
Branka Nakomcic ◽  
...  
Keyword(s):  
Alternative Energy ◽  
Landfill Gas ◽  
Energy Utilization ◽  
Gas Generation ◽  
Methane Generation ◽  
Alternative Energy Sources ◽  
And Migration ◽  
Novi Sad ◽  
Resources Exploitation

Researches in the area of landfill gas generation and energy utilization are currently underway and widespread in the world for several reasons: reducing effects of greenhouse gases, possibilities for utilizing alternative energy sources, reducing conventional energy resources exploitation, and environmental protection. First part of this research is conducted with an aim to establish the influence of meteorological parameters, primarily ambience temperature, on the methane generation processes at Novi Sad landfill. The second part of the research refers to functional characteristics of landfill such as the waste age, closing practice, and the age of certain parts of landfill body, as well as the waste depth and quantity of generated methane. Based on several years of investigation, it is concluded that methane generation varies in the range of 0-34 vol.% m3/m3, and that seasonal variations have significant influence on methane generation. At low temperatures, during winter, methane generation and migration is stagnant while in summer periods, due to higher temperatures, the process of methane generation is more intensive.

INTEGRATED SOURCE, MATURATION AND MIGRATION ANALYSIS, GIPPSLAND BASIN, AUSTRALIA

1992 ◽  
Vol 32 (1) ◽  
pp. 313 ◽  
Author(s):  
P. S. Moore ◽  
B. J. Burns ◽  
J. K. Emmett ◽  
D. A. Guthrie
Keyword(s):  
Source Rocks ◽  
Source Distribution ◽  
Integrated Analysis ◽  
Peak Oil ◽  
Gas Generation ◽  
Southeastern Part ◽  
Migration Pathway ◽  
And Migration ◽  
Gippsland Basin ◽  
Migration Pathways

Biomarker geochemistry, maturation modelling and migration pathway analysis have been used in a new, integrated analysis of the Gippsland Basin. The analysis has resulted in the development of a predictive model for hydrocarbon charge and oil versus gas split. The study was carried out in 4 parts: analytical geochemistry, source distribution mapping, maturation modelling and migration pathway analysis.New geochemical biomarker studies confirm a non-marine source for the oils, but place peak oil generation in the upper part of the traditional oil window. Gas in the basin is mainly derived from overmature source rocks. Coals were recognised to contribute significantly to oil generation.The source rock thickness and distribution for the entire basin were mapped using analytical techniques plus wireline log analysis, coupled with seismic structural mapping and facies analysis. Prime oil-prone source rocks were found to be located in the lower coastal plain depositional environment. Extrapolations were necessary for older rocks, using stratigraphic models.Maturation modelling modelling of selected wells and synclines was carried out and an overall basin model constructed. Post-structuring yields of oil and gas were also derived. A key result was the lack of post-structuring overmature gas generation in the oil prone southeastern part of the basin, owing to high palaeo-temperatures associated with earlier rifting.Analysis of present day and palaeo-migration pathways gave an excellent match between predicted oil versus gas ratios and discoveries, both geographically and stratigraphically. The tool is now being used in a predictive mode to highgrade basin prospectivity.

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