The Nirex Coherent Approach to Achieving Criticality Safety

2003 ◽  
Author(s):  
P. Wood ◽  
M. Askarieh ◽  
P. Lock
Keyword(s):  
Control Process ◽  
Fissile Material ◽  
Objective Evidence ◽  
Safety Assessments ◽  
The Government ◽  
Environmentally Sound ◽  
The Uk ◽  
High Level ◽  
Criticality Safety

The role of Nirex is to provide the UK with safe, environmentally sound and publicly acceptable options for the long-term management of radioactive materials. This will include all intermediate-level waste and some low-level waste (ILW and LLW). Nirex has developed a Phased Disposal Concept based on conditioning the wastes then isolating them deep underground. Based on this phased disposal concept, Nirex advises waste producers on the conditioning and packaging of radioactive waste. The ILW and LLW which comprise the ‘reference volume’ of the Phased Disposal Concept contain approximately 5 t Pu-239 and 28 t U-235. Nirex’s work is based on a number of standards for safety and environmental protection set by the Government. Three different Regulators ensure application of these standards in the transport, operation and post-closure phases. Therefore a coherent approach to criticality safety is required. The approach to criticality safety begins by avoiding criticality resulting from the way in which the waste is packaged, by controlling the package design including the level of fissile material. The concept safety assessments will support a screening level of approximately 5 g Pu-239 equivalent. In specific cases where waste producers indicate that their proposed packages will not comply with the screening level, package-specific criticality safety assessments can be incorporated into the concept through the change control process. Engineering measures are available to prevent criticality for such time as the waste packaging affords a high level of containment. In the long term, however, after deterioration of the physical containment provided by the waste packages, there would be the possibility of movement of fissile material out of the waste packages and subsequent accumulation into new configurations which could in principle lead to a criticality. It is conceivable that a criticality could adversely impact on the performance of a repository after closure because, for example, of the heat that would be produced affecting the engineered barriers. It is therefore necessary to consider the post-closure criticality safety of the repository concept. Nirex is currently undertaking a programme of work on ‘understanding criticality under repository conditions’. The aim of the programme is to obtain a better understanding of the processes that would control the nature and magnitude of a criticality under the particular conditions of the concept repository. An essential component of demonstrating criticality safety is to ensure waste packagers develop operating arrangements, and provide objective evidence in the form of criticality compliance assurance documentation, to demonstrate how fissile material will be controlled to meet levels defined in concept criticality safety assessments. This paper will describe the coherent approach and the processes by which it is applied.

Durability of potential plutonium wasteforms under repository conditions

2012 ◽  
Vol 76 (8) ◽  
pp. 2911-2918 ◽  
Author(s):  
G. Deissmann ◽  
S. Neumeier ◽  
G. Modolo ◽  
D. Bosbach
Keyword(s):  
Chemical Reactivity ◽  
Final Decision ◽  
Geological Disposal ◽  
Aqueous Environments ◽  
Safety Case ◽  
Key Issues ◽  
The Uk ◽  
High Level ◽  
Radionuclide Release

AbstractSeparated stocks of UK civil plutonium are currently held as a zero value asset in storage, as there is no final decision about whether they should be treated as a resource for future use as nuclear fuel or as waste. Irrespective of future UK government strategies regarding plutonium, at least a portion of the UK civil plutonium inventory will be designated for geological disposal. In this context, we performed a high-level review of the performance of potential wasteforms for the disposal of separated civil plutonium. The key issues considered were the durability and chemical reactivity of the wasteforms in aqueous environments and the long-term radionuclide release under conditions relevant to geological disposal. The major findings of the review, relevant not only to the situation in the UK but to plutonium disposal in general, are summarized in this paper. The review showed that, in the event of a decision being taken to declare plutonium as a waste for disposal, more systematic studies would be required to constrain the wasteform performance under repository conditions in order to derive realistic source terms for a safety case.

Significance of long-term climate evolution and associated impacts on the long-term safety of a high-level radioactive waste repository within the German siting process

2021 ◽  
Author(s):  
Marc Wengler ◽  
Astrid Göbel ◽  
Eva-Maria Hoyer ◽  
Axel Liebscher ◽  
Sönke Reiche ◽  
...  
Keyword(s):  
Radioactive Waste ◽  
Site Selection ◽  
Phase 1 ◽  
High Level Radioactive Waste ◽  
Safety Requirements ◽  
Climate Evolution ◽  
Safety Assessments ◽  
High Level ◽  
Host Rocks

<p>According to the 'Act on the Organizational Restructuring in the Field of Radioactive Waste Disposal' the BGE was established in 2016. The amended 'Repository Site Selection Act' (StandAG) came into force in July 2017 and forms the base for the site selection by clearly defining the procedure. According to the StandAG the BGE implements the participative, science-based, transparent, self-questioning and learning procedure with the overarching aim to identify the site for a high-level radioactive waste (HLW) repository in a deep geological formation with best possible safety conditions for a period of one million years.</p><p>The German site selection procedure consists of three phases, of which Phase 1 is divided into two steps. Starting with a blanc map of Germany, the BGE completed Step 1 in September 2020 and identified 90 individual sub-areas that provide favorable geological conditions for the safe disposal of HLW in the legally considered host rocks; rock salt, clay and crystalline rock. Based on the results of Step 1, the on-going Step 2 will narrow down these sub-areas to siting regions for surface exploration within Phase 2 (§ 14 StandAG). Central to the siting process are representative (Phase 1), evolved (Phase 2) and comprehensive (Phase 3) preliminary safety assessments according to § 27 StandAG.</p><p>The ordinances on 'Safety Requirements' and 'Preliminary Safety Assessments' for the disposal of high-level radioactive waste from October 2020 regulate the implementation of the preliminary safety assessments within the different phases of the siting process. Section 2 of the 'Safety Requirements' ordinance provides requirements to evaluate the long-term safety of the repository system; amongst others, it states that all potential effects that may affect the long-term safety of the repository system need to be systematically identified, described and evaluated as “expected” or “divergent” evolutions. Additionally, the ordinance on 'Preliminary Safety Assessments' states in § 7, amongst others, that the geoscientific long-term prediction is a tool to identify and to evaluate geogenic processes and to infer “expected” and “divergent” evolutions from those. Hence, considering the time period of one million years for the safe disposal of the HLW and the legal requirements, it is essential to include long-term climate evolution in the German site selection process to evaluate the impact of various climate-related scenarios on the safety of the whole repository system.</p><p>To better understand and evaluate the influence of climate-related processes on the long-term safety of a HLW repository, climate-related research will be a part of the BGE research agenda. Potential research needs may address i) processes occurring on glacial – interglacial timescales (e.g. the inception of the next glaciation, formation and depth of permafrost, glacial troughs, sub-glacial channels, sea-level rise, orbital forcing) and their future evolutions, ii) effects on the host rocks and the barrier system(s) as well as iii) the uncertainties related to these effects but also to general climate models and predictions.</p>

Geospatial data in the UK

2019 ◽  
Vol 33 (1) ◽  
pp. 27-41 ◽  
Author(s):  
Suzanne Jozefowicz ◽  
Merlin Stone ◽  
Eleni Aravopoulou
Keyword(s):  
Western Country ◽  
Geospatial Data ◽  
Content Type ◽  
Research Findings ◽  
Potential Benefits ◽  
Uk Government ◽  
The Government ◽  
The Uk

Purpose The purpose of this paper is to explain the rise of geospatial data, its importance for business and some of the problems associated with its development and use. Design/methodology/approach The paper reviews a certain amount of previously published literature but is based mainly on analysis of the very large number of responses to a consultation paper on geospatial data published by the UK Government. Findings The findings are that while there is strong appreciation of the potential benefits of using geospatial data, there are many barriers to the development, sharing and use of geospatial data, ranging from problems of incompatibility in data definitions and systems to regulatory issues. The implication for governments and for providers and users of geospatial data relates to the need to take a long-term approach to planning in resolving the issues identified. Research limitations/implications The research findings are limited to the UK, but similar findings would be likely in any other large Western country. Practical implications This paper confirms the need for a strong and coherent approach to the planning of geospatial data and systems for the establishment of a clear basis for the different parties to work together and the need to clearly separate the roles of the government in establishing frameworks and standards and the role of the private sector in developing applications and solutions. Social implications Society is increasingly dependent on the use of geospatial data, in improving living standards and dealing with social problems. The recommendations identified in this paper, if followed, will facilitate these improvements. Originality/value The value of this paper is the tight synthesis that it provides of a wide ranging and complex range of responses to the UK Government consultation and placing these responses in the wider context of the development of geospatial data.

Farmers' attitudes towards sustainable agriculture issues and environmental quality in a selected area of Bangladesh

1999 ◽  
Vol 14 (1) ◽  
pp. 22-29 ◽  
Author(s):  
M. Z. Rahman ◽  
H. Mikuni
Keyword(s):  
Agricultural Development ◽  
Management Practices ◽  
Productivity Loss ◽  
Favorable Attitude ◽  
Agricultural Technologies ◽  
Aquatic Life ◽  
The Government ◽  
The Individual ◽  
High Level

AbstractThe sustainability issues associated with agricultural development are a growing concern worldwide. This study focussed on farmers' attitudes about environmental degradation and long term productivity loss that may result from implementation of modern agricultural technologies. The study was conducted in a selected area of Bangladesh and field level data were collected from the sampled farmers through personal interviewing. Findings revealed that more than two-thirds of the farmers confronted either a medium or high level of environmental problems due to intensive cultivation. Their main concerns were stress on soil fertility, loss of essential aquatic life, and reduction of earthworms and other beneficial organisms in soil. The farmers' recommended solutions were production of high yielding crop varieties with conservation management practices, and the balanced use of chemical fertilizers and organic manures. To apply these techniques, the top expectation of the farmers was to receive subsidies for agricultural inputs, and get easy-term credit from the government or non-government organizations. Interestingly, just half the farmers in the study area possessed a less than favorable attitude towards sustainability issues of agricultural development. In other words, to them these issues were of low or marginal priority. Only 6% of them expressed a highly favorable attitude (high priority) and 44% expressed a moderate attitude. Based on correlations, the individual farmer's age, education, family size, organizational participation, television exposure, communication behavior and environmental problem confrontation were identified as the main determinants of their attitudes about sustainability issues. Hence, these factors should be considered when formulating programs and policies for agriculture development that aim for long-term sustainability.

Creating a Ten-Year Science and Innovation Framework for the UK

2006 ◽  
Vol 20 (3) ◽  
pp. 175-181
Author(s):  
Edward F. Crawley ◽  
Suzanne B. Greenwald
Keyword(s):  
Public Service ◽  
Scientific Knowledge ◽  
Knowledge System ◽  
Goods And Services ◽  
Scientific Innovation ◽  
End Products ◽  
Knowledge Intensive ◽  
The Uk ◽  
High Level

The sustainability of a competitive, national economy depends largely on the ability of companies to deliver innovative knowledge-intensive goods and services to the market. These are the ultimate outputs of a scientific knowledge system. Ideas flow from the critical, identifiable phases of (a) the discovery, (b) the development, (c) the deployment and (d) the delivery of end products. In order to develop a successful ten-year strategic framework for investment in science and innovation, the UK government will need to prioritize and secure contributions to economic development and public service. One particular goal of the framework would be to identify the desirable attributes of a knowledge system that could achieve these ambitions. The Cambridge–MIT Institute (CMI) interviewed US stakeholders in science and innovation to gather insights on the UK's potential for long-term, scientific innovation, and the critical processes that fuel it. This paper reviews high-level observations, proposes a model for a scientific knowledge system and outlines its critical attributes.

Adsorption of actinides within speleothems

2016 ◽  
Vol 80 (5) ◽  
pp. 765-780 ◽  
Author(s):  
P. Sengupta ◽  
J. Sanwal ◽  
N. L. Dudwadkar ◽  
S. C. Tripathi ◽  
P. M. Gandhi
Keyword(s):  
Valence State ◽  
Experimental Studies ◽  
Distribution Coefficients ◽  
Nuclear Wastes ◽  
Lesser Himalayas ◽  
Safety Assessments ◽  
High Level ◽  
Long Term Performance ◽  
Term Performance

AbstractStalagmites and stalactites, as observed within natural caves, may develop inside geological repositories during constructional and post-operational periods. It is therefore important to understand actinide sorption within such materials. Towards this, experimental studies were carried out with 233U, 238Np (VI), 238Np (IV), 239Pu and 241Am radiotracers using natural speleothem samples collected from the Dharamjali cave of the Kumaon Lesser Himalayas, India. Petrological/mineralogical studies showed that natural speleothems have three general domains: (1) columnar calcite; (2) microcrystalline calcite; and (3) botryoidal aragonite – each with ferruginous materials. Results showed that all domains of speleothems can take up >99% actinides, irrespective of valence state and pH (1–6 range) of the solution. However, distribution coefficients were found to be at a maximum in aragonite for most of the actinides. Such data are very important for long-term performance and safety assessments of the deep geological repositories planned for the disposal of high-level nuclear wastes.

scholarly journals Boris Johnson to the Rescue? How the Conservatives Won the Radical-Right Vote in the 2019 General Election

2021 ◽  
pp. 003232172110511
Author(s):  
Geoffrey Evans ◽  
Roosmarijn de Geus ◽  
Jane Green
Keyword(s):  
Panel Study ◽  
General Election ◽  
Radical Right ◽  
Strategic Issue ◽  
Radical Right Parties ◽  
The Government ◽  
The Uk

How can centre–right parties in majoritarian systems adapt to threats from the radical right? Using a long-term inter-election panel study, we identify a remarkably stable constituency of support for Britain’s recent radical-right parties – the UK Independence Party and the Brexit Party. We show also how these same voters defected from the Conservatives across elections. In response, the government used a combination of the election of a new leader, Boris Johnson, and a hardline position on Brexit to reincorporate these voters into its support base, helping to lead to a large Conservative majority in 2019. Cross-party evaluations of Johnson were even more important in influencing this success than the issue of Brexit itself. Effective centre–right adaption to radical-right challenges is not simply about strategic issue positioning, it can also derive from centre–right leaders with populist appeal.

The Management of Historic Intermediate Level Radioactive Waste in the United Kingdom

2003 ◽  
Author(s):  
David Horsley ◽  
Bruce McKirdy
Keyword(s):  
United Kingdom ◽  
Radioactive Waste ◽  
Waste Management ◽  
Storage Conditions ◽  
Intermediate Level ◽  
The United Kingdom ◽  
Environmentally Sound ◽  
Intermediate Level Radioactive Waste ◽  
The Uk

Nirex is the organisation responsible for long-term radioactive waste management in the UK. Our Mission is to provide the UK with safe, environmentally sound and publicly acceptable options for the long-term management of radioactive materials. The United Kingdom has a significant legacy of long-lived intermediate level radioactive waste. This has arisen from 50 years of investigation and exploitation of nuclear technology. Some of the waste is stored in old facilities that do not provide the standards of containment that would be incorporated in modern facilities. Also the risk to people and to the environment from the inventory in these facilities will increase with time as the structures age and degrade, increasing the chance of containment failure. There is, therefore, a need to retrieve this raw waste and process and package it to make it demonstrably safe for continued storage, pending a decision on disposal of radioactive waste. This packaging should, as far as is practicable, be compatible with the UK long-term waste management strategy. Nirex has developed its Phased Disposal Concept for intermediate and low-level radioactive waste. Based on that concept, Nirex has developed waste package specifications and carries out assessments of waste packaging proposals. For legacy wastes it may not always practicable to demonstrate full compliance with all Nirex disposal criteria. This paper describes an approach, agreed between Nirex and BNFL, for managing these wastes. The proposed approach takes account of long-term waste management issues whilst recognising the need for timely improvement of storage conditions.

Assessment of Factors Underpinning Employee’s Interest and Preference for Telecommuting in Lagos Island, Lagos, Nigeria

2021 ◽  
Vol 1 (4) ◽  
pp. 276-286
Author(s):  
Koleayo Oluwafemi Omoyajowo ◽  
Adeyemi Adewale Akinola ◽  
Mary Adetutu Adewunmi ◽  
Grace Ojo-Emmanuel ◽  
Allen Ebosiem ◽  
...  
Keyword(s):  
Marital Status ◽  
Labor Productivity ◽  
Public Awareness ◽  
Work Life ◽  
Weak Relationship ◽  
Inferential Analysis ◽  
Environmentally Sound ◽  
High Level

Public awareness on environmentally sound practices viz-a-viz strategies that may also sustain a balanced work life culture cannot be overemphasized. Telecommuting represents one of those viable environmentally sound practices that offer flexibility to employees through working from their homes which to a great extent have improved employee’s productivity. This study assessed the level of awareness about telecommuting as well as the factors underpinning employee’s interest and preference for telecommuting in Lagos, Nigeria. A total of 220 responses from structured questionnaires was designed to capture the level of awareness, interest, readiness, and perception of employees towards telecommuting in Lagos Island, both descriptive and inferential analysis was used for the study. The study shows that 72% were aware of telecommuting and its associated benefits while about 90% opined that telecommuting will be suitable to their work. There was also a significant positive but weak relationship among employee’s preference for telecommuting and factors such as age, marital status, awareness about telecommuting, and the experience of traffic gridlock and its associated stress .This study concluded that with the high level of awareness of telecommuting, organisations should gainfully harness the wide array of prospects that accompanies the adoption of telecommuting which has the long term advantage of stimulating labor productivity.

Long-term sickness and invalidity benefits: Forecasting and other actuarial problems

1987 ◽  
Vol 114 (3) ◽  
pp. 467-550 ◽  
Author(s):  
S. Haberman
Keyword(s):  
Social Security ◽  
Social Security System ◽  
Security System ◽  
Social Security Systems ◽  
Security Systems ◽  
Insurance Benefit ◽  
Disability Claim ◽  
The Government ◽  
The Uk

It is proposed to discuss the actuarial problems associated with the management of long-term sickness and invalidity benefits. The emphasis is on benefits provided by social security schemes (with particular reference to National Insurance benefit in the UK), but the main points are relevant to private sector benefits including permanent health insurance (PHI).The plan of the paper is as follows. We describe in Section 2 the nature of long-term invalidity benefit provided by the British social security system and then consider in Section 3 the problems associated with defining disability. A discussion of the differences between the incidence of morbidity and the making of an insurance claim leads to consideration of selection and moral hazard (Section 4). We then examine in Section 5 the methodology for analysing costs and estimating future costs with particular reference to the development within the Government Actuary's Department (GAD) of a model based on an incidence and survivorship approach to invalidity benefit and the debate aroused by CMI Report No. 7 on the same topic5. The paper then presents an analysis of recent trends in disability claim rates (Section 6) and incidence and termination rates (Sections 7 and 8) based on invalidity benefit within the British social security system, as well as PHI and the experience of other countries. Attempts are then made in Section 9 to explain these trends and the upward trend in financial costs for disability benefits experienced by many social security systems. The paper concludes with an examination of two areas of current interest, viz. sex differences in morbidity rates and claim rates (Section 10) and the relationship between claim rates and the prevailing level of unemployment (Section 11).

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