Surveys of the radionuclide content of land areas that may have been contaminated are required to... more Surveys of the radionuclide content of land areas that may have been contaminated are required to determine whether there is an existing hazard to workers or the public. The objectives of this paper are to compare the results and uncertainties of in situ and ex situ measurements on land areas at a decommissioning nuclear site for the three different survey objectives, and to propose a new method for estimating the size and shape of in situ specimens that can be used to optimise the design of objective-driven in situ surveys.
The noble objective of this book is too explain ground water chemistry for the benefit of enginee... more The noble objective of this book is too explain ground water chemistry for the benefit of engineers and hydrogeologists. In this respect, not many new ideas are included in the book, but the way concepts are taken from an introductory to an advanced level is fascinating. In the first 50 ...
In the UK alone, it is estimated that there may be 20,000,000 cubic metres of contaminated land a... more In the UK alone, it is estimated that there may be 20,000,000 cubic metres of contaminated land at Sellafield. Harwell and Dounreay are known also to have significant amounts of radioactive or non-radioactive contaminated land. It is therefore important to devise optimal methods for the characterisation of areas of land for radionuclide content, in order to enable cost-effective decommissioning. With chemical contaminants, ex situ measurements are made on a larger volume of soil than are in situ measurements. However, the opposite is often true for the characterisation of radioactive contamination, when this involves the detection of penetrating radiation from γ-emitting radionuclides. This means that when investigating for hotspots of radioactive contamination at or near the ground surface, better coverage can be obtained using in situ methods. This leads to the question, what is the optimal strategy (e.g. percentage coverage, counting time) for in situ characterisation of radioact...
Quarterly Journal of Engineering Geology and Hydrogeology, 2018
Papers published in QJEGH illustrate advances in the monitoring and measurement of groundwater sy... more Papers published in QJEGH illustrate advances in the monitoring and measurement of groundwater systems over the last 50 years. The emphasis of QJEGH over the years has tended to be towards practice in hydrogeology in the UK, rather than theory, and therefore we refer also to some seminal work published elsewhere. The range of measurements and monitoring reviewed includes from laboratory to regional scale, physical measurement of groundwater flow and transport within groundwater, geophysical, chemical and thermal properties, and applies both to resources and pollution. Several themes can be recognized: groundwater resource development (especially in the early days), groundwater quality protection, initially focused on landfill but now including industrial and diffuse pollution, groundwater management integrated into wider environmental management since the European Water Framework Directive in 2000, and latterly novel uses of groundwater, in part driven by a desire for ‘clean’ energy. We conclude by looking at future drivers and technologies to consider how the practice of monitoring and measurement of groundwater systems may evolve in coming years and some of the challenges that we will need to overcome.
Quarterly Journal of Engineering Geology and Hydrogeology, 2018
In the UK, the Environmental Protection Act requires land to be determined as contaminated if it ... more In the UK, the Environmental Protection Act requires land to be determined as contaminated if it contains concentrations of substances such that there is significant risk of significant harm to certain defined receptors. A key step in assessing the possibility of significant harm is the comparison of measured soil concentrations of potentially harmful substances with appropriate assessment levels considered to represent tolerable levels of risk. Guidance on making the comparison using statistical techniques was issued in 2008 by the Chartered Institute of Environmental Health (CIEH) and Contaminated Land: Applications in Real Environments (CL:AIRE) (the CL:AIRE–CIEH method). When making decisions on the basis of a finite number of measurements from a very large amount of soil, there is always the possibility of error. It has become apparent that the CL:AIRE–CIEH approach does not necessarily control the likelihood of determining that land is not contaminated when in fact it is contaminated, and this is more likely when using the Chebyshev test. Although there are methods to control such likelihood, there is no clear basis for the necessary specifications. The difficulties can be obviated by making a determination of contamination at 50% probability, which is consistent with the statutory guidance. Alternatively, a different approach may be taken to decision-making.
Quarterly Journal of Engineering Geology and Hydrogeology, 2019
If a change of use for industrial land is proposed in the UK, there is usually a requirement to d... more If a change of use for industrial land is proposed in the UK, there is usually a requirement to demonstrate that the change of use will not result in the land becoming Contaminated Land, as defined under the Environmental Protection Act 1990. Under certain circumstances, this demonstration can be made by showing that the mean concentration of contaminants of potential concern is below a suitable assessment level appropriate to the proposed new use. How much sampling effort is required for this purpose? Using a relatively large dataset for arsenic in soil, a developed approach is presented to determine the number of measurements required for a clearance investigation to demonstrate absence of contamination based on minimizing expectation of financial loss, taking into account both the actual cost of investigation and the possible cost of incorrectly determining that contamination is still present and undertaking unnecessary remediation. Abstract probabilities are discussed in terms of money spent and money potentially saved. Supplementary material: an Excel spreadsheet containing the full dataset, showing its sub-sampling, is available at https://doi.org/10.6084/m9.figshare.c.4415039
To further the understanding of the relationships between past climatic conditions and the hydrog... more To further the understanding of the relationships between past climatic conditions and the hydrogen and oxygen isotope composition of old groundwaters, a study of the relationship between the composition of daily rainfall and meteorological parameters at a single site was made. The composition of daily rainfall was found to be extremely variable, with little seasonal dependence, and with no clear relationship to daily mean air temperature. This is typical of a maritime climate, although the site studied is located on the east coast of England. The most important control on composition is the origin of the precipitating air mass, whether Atlantic or Continental. The possibility of investigating past climates is discussed.
IONTENTS Acknowledgements Foreword 1 Problems and Opportunities i Our inheritance 1 Industrialisa... more IONTENTS Acknowledgements Foreword 1 Problems and Opportunities i Our inheritance 1 Industrialisation i A change of heart 3 The future 3 How to use this book 4 Box 1.1 The global metropolis 5 2 Setting the Scene 7 Natural Rivers 7 The natural water cycle 7 Living rivers 1 2 From prehistory to ...
Journal of radiological protection : official journal of the Society for Radiological Protection, 2014
Measurements made in situ with gamma detectors and ex situ measurements of soil samples in a labo... more Measurements made in situ with gamma detectors and ex situ measurements of soil samples in a laboratory can have complementary roles in the assessment of radioactively contaminated land on decommissioning nuclear sites. Both in situ and ex situ methods were used to characterize (137)Cs contamination within an area at the Dounreay site in Scotland. The systematic difference (bias) between estimates of the mean activity concentration was found to be non-significant when in situ measurements were interpreted using a linear depth model, based on ex situ measurements made at two different depths. An established method of evaluating the random components of measurement uncertainty was used. The random component of analytical uncertainty in the in situ measurements, made in field conditions, was found to exceed that for the ex situ measurements, made in the controlled conditions of a laboratory. However, contamination by the target radionuclide was found to be heterogeneous over small spat...
A key challenge in disposing of nuclear legacy facilities and planning a new nuclear plant is how... more A key challenge in disposing of nuclear legacy facilities and planning a new nuclear plant is how to assess the extent or likelihood of radioactive contamination in construction materials and the ground. This paper summarises the status of two techniques based on the analysis of emitted radiation from materials that comprise such structures, and describes how this analysis can be used to infer the depth of contamination without the need to penetrate the structure or to destroy it in the process. Two experimental facilities have been developed to test the efficacy of these techniques, and data are provided for the most widespread contaminant experienced in the sector: caesium-137. Finally, the influence on the technique of the likely variety of silica-based media to be encountered in the nuclear industry is described, together with a summary of challenges to be addressed in future research.
Surveys of the radionuclide content of land areas that may have been contaminated are required to... more Surveys of the radionuclide content of land areas that may have been contaminated are required to determine whether there is an existing hazard to workers or the public. The objectives of this paper are to compare the results and uncertainties of in situ and ex situ measurements on land areas at a decommissioning nuclear site for the three different survey objectives, and to propose a new method for estimating the size and shape of in situ specimens that can be used to optimise the design of objective-driven in situ surveys.
The noble objective of this book is too explain ground water chemistry for the benefit of enginee... more The noble objective of this book is too explain ground water chemistry for the benefit of engineers and hydrogeologists. In this respect, not many new ideas are included in the book, but the way concepts are taken from an introductory to an advanced level is fascinating. In the first 50 ...
In the UK alone, it is estimated that there may be 20,000,000 cubic metres of contaminated land a... more In the UK alone, it is estimated that there may be 20,000,000 cubic metres of contaminated land at Sellafield. Harwell and Dounreay are known also to have significant amounts of radioactive or non-radioactive contaminated land. It is therefore important to devise optimal methods for the characterisation of areas of land for radionuclide content, in order to enable cost-effective decommissioning. With chemical contaminants, ex situ measurements are made on a larger volume of soil than are in situ measurements. However, the opposite is often true for the characterisation of radioactive contamination, when this involves the detection of penetrating radiation from γ-emitting radionuclides. This means that when investigating for hotspots of radioactive contamination at or near the ground surface, better coverage can be obtained using in situ methods. This leads to the question, what is the optimal strategy (e.g. percentage coverage, counting time) for in situ characterisation of radioact...
Quarterly Journal of Engineering Geology and Hydrogeology, 2018
Papers published in QJEGH illustrate advances in the monitoring and measurement of groundwater sy... more Papers published in QJEGH illustrate advances in the monitoring and measurement of groundwater systems over the last 50 years. The emphasis of QJEGH over the years has tended to be towards practice in hydrogeology in the UK, rather than theory, and therefore we refer also to some seminal work published elsewhere. The range of measurements and monitoring reviewed includes from laboratory to regional scale, physical measurement of groundwater flow and transport within groundwater, geophysical, chemical and thermal properties, and applies both to resources and pollution. Several themes can be recognized: groundwater resource development (especially in the early days), groundwater quality protection, initially focused on landfill but now including industrial and diffuse pollution, groundwater management integrated into wider environmental management since the European Water Framework Directive in 2000, and latterly novel uses of groundwater, in part driven by a desire for ‘clean’ energy. We conclude by looking at future drivers and technologies to consider how the practice of monitoring and measurement of groundwater systems may evolve in coming years and some of the challenges that we will need to overcome.
Quarterly Journal of Engineering Geology and Hydrogeology, 2018
In the UK, the Environmental Protection Act requires land to be determined as contaminated if it ... more In the UK, the Environmental Protection Act requires land to be determined as contaminated if it contains concentrations of substances such that there is significant risk of significant harm to certain defined receptors. A key step in assessing the possibility of significant harm is the comparison of measured soil concentrations of potentially harmful substances with appropriate assessment levels considered to represent tolerable levels of risk. Guidance on making the comparison using statistical techniques was issued in 2008 by the Chartered Institute of Environmental Health (CIEH) and Contaminated Land: Applications in Real Environments (CL:AIRE) (the CL:AIRE–CIEH method). When making decisions on the basis of a finite number of measurements from a very large amount of soil, there is always the possibility of error. It has become apparent that the CL:AIRE–CIEH approach does not necessarily control the likelihood of determining that land is not contaminated when in fact it is contaminated, and this is more likely when using the Chebyshev test. Although there are methods to control such likelihood, there is no clear basis for the necessary specifications. The difficulties can be obviated by making a determination of contamination at 50% probability, which is consistent with the statutory guidance. Alternatively, a different approach may be taken to decision-making.
Quarterly Journal of Engineering Geology and Hydrogeology, 2019
If a change of use for industrial land is proposed in the UK, there is usually a requirement to d... more If a change of use for industrial land is proposed in the UK, there is usually a requirement to demonstrate that the change of use will not result in the land becoming Contaminated Land, as defined under the Environmental Protection Act 1990. Under certain circumstances, this demonstration can be made by showing that the mean concentration of contaminants of potential concern is below a suitable assessment level appropriate to the proposed new use. How much sampling effort is required for this purpose? Using a relatively large dataset for arsenic in soil, a developed approach is presented to determine the number of measurements required for a clearance investigation to demonstrate absence of contamination based on minimizing expectation of financial loss, taking into account both the actual cost of investigation and the possible cost of incorrectly determining that contamination is still present and undertaking unnecessary remediation. Abstract probabilities are discussed in terms of money spent and money potentially saved. Supplementary material: an Excel spreadsheet containing the full dataset, showing its sub-sampling, is available at https://doi.org/10.6084/m9.figshare.c.4415039
To further the understanding of the relationships between past climatic conditions and the hydrog... more To further the understanding of the relationships between past climatic conditions and the hydrogen and oxygen isotope composition of old groundwaters, a study of the relationship between the composition of daily rainfall and meteorological parameters at a single site was made. The composition of daily rainfall was found to be extremely variable, with little seasonal dependence, and with no clear relationship to daily mean air temperature. This is typical of a maritime climate, although the site studied is located on the east coast of England. The most important control on composition is the origin of the precipitating air mass, whether Atlantic or Continental. The possibility of investigating past climates is discussed.
IONTENTS Acknowledgements Foreword 1 Problems and Opportunities i Our inheritance 1 Industrialisa... more IONTENTS Acknowledgements Foreword 1 Problems and Opportunities i Our inheritance 1 Industrialisation i A change of heart 3 The future 3 How to use this book 4 Box 1.1 The global metropolis 5 2 Setting the Scene 7 Natural Rivers 7 The natural water cycle 7 Living rivers 1 2 From prehistory to ...
Journal of radiological protection : official journal of the Society for Radiological Protection, 2014
Measurements made in situ with gamma detectors and ex situ measurements of soil samples in a labo... more Measurements made in situ with gamma detectors and ex situ measurements of soil samples in a laboratory can have complementary roles in the assessment of radioactively contaminated land on decommissioning nuclear sites. Both in situ and ex situ methods were used to characterize (137)Cs contamination within an area at the Dounreay site in Scotland. The systematic difference (bias) between estimates of the mean activity concentration was found to be non-significant when in situ measurements were interpreted using a linear depth model, based on ex situ measurements made at two different depths. An established method of evaluating the random components of measurement uncertainty was used. The random component of analytical uncertainty in the in situ measurements, made in field conditions, was found to exceed that for the ex situ measurements, made in the controlled conditions of a laboratory. However, contamination by the target radionuclide was found to be heterogeneous over small spat...
A key challenge in disposing of nuclear legacy facilities and planning a new nuclear plant is how... more A key challenge in disposing of nuclear legacy facilities and planning a new nuclear plant is how to assess the extent or likelihood of radioactive contamination in construction materials and the ground. This paper summarises the status of two techniques based on the analysis of emitted radiation from materials that comprise such structures, and describes how this analysis can be used to infer the depth of contamination without the need to penetrate the structure or to destroy it in the process. Two experimental facilities have been developed to test the efficacy of these techniques, and data are provided for the most widespread contaminant experienced in the sector: caesium-137. Finally, the influence on the technique of the likely variety of silica-based media to be encountered in the nuclear industry is described, together with a summary of challenges to be addressed in future research.
Uploads