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At least 937 records · Page 52

From passive storage to daily waste retrieval; changing the working culture at Sellafield's pile fuel storage pond

The Pile Fuel Storage Pond (PFSP) was built in 1948/50 to treat materials from the Windscale Piles. Multiple operational regimes over the intervening 60 years have resulted in a complex inventory of spent nuclear fuels, solid and liquid intermediate level wastes. A coordinated programme of work, designed to retrieve and safely dispose of the pond contents, has been implemented to enable the decommissioning of the facility. The long period of passive storage operations which preceded the implementation of the programme meant that the operator was faced with a dual challenge of providing new technical capability and changing a working culture that was inappropriate for the dynamic environment required to successfully deliver the programme. It was recognised that the nature of the programme meant that implementing a standard manufacturing approach to operations would not be appropriate. In order to create a dynamic retrievals focussed working culture, the operator has vigorously embraced change programmes aimed at improving a number of working practices including encouraging innovation, managing integrated but flexible production schedules, and encouraging work-face problem solving. The combined impact of beginning to resolve the technical challenges and focussing on the delivery culture has resulted in the facility making a step change towards becoming fully retrievals operations focussed. (authors)

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Upstream Optioneering: Optimising Higher Activity Waste Management

The Upstream Optioneering project was created by the Nuclear Decommissioning Authority (NDA) Radioactive Waste Management Directorate (RWMD) to support the development and implementation of opportunities to optimise the management of UK higher activity waste, spent fuel and other materials that may be disposed of in a geological disposal facility. The project works in an integrative manner with the NDA, RWMD and waste producers, and was split into three phases: - In Phase 1 waste management opportunities were identified and collated from across the NDA estate. - In Phase 2, opportunities collated during Phase 1, were further consolidated, analysed and prioritised to develop a three year work programme. Prioritisation ensured that resources were deployed appropriately and opportunities can be realised before the potential benefit diminishes. - Phase 3, which began in April 2012, comprises a three year work programme to address the prioritised opportunities. Work varies from direct implementation of opportunities to scoping studies that may pave the way for more detailed subsequent work by Site Licence Companies. The work programme is flexible and, subject to change control, varies depending on the needs of project sponsors (RWMD, NDA Strategy and NDA Delivery). This paper provides an overview of the Upstream Optioneering project (focusing particularly on Phases 2 and 3), summarises work carried out to date within the three year work programme, and provides some examples of the main findings concerning specific opportunities from Year One of the Phase 3 work programme. (authors)

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Sentinel

Network intrusion detection systems (NIDS) are commonplace in network security but they frequently employ algorithms that are computational demanding requiring hardware and software with significant power requirements. Two examples of such resource-intensive algorithms used for network security are regular expression matching and broader signature pattern matching which are commonly used in deep packet inspection (DPI). Network security algorithms that have large power requirements may be a challenge for low-power internet-of-things (IoT) environments, which generally lack the power resources to implement complex security measures like computationally expensive DPI at the edge. Furthermore, IoT environments incorporating 5G standalone networks have network latency constraints beyond just power that make DPI at the edge even more difficult. Programmable logic is ideally suited for machine learning inference for DPI because of its deep instruction level parallelism and single-cycle memory access. Machine learning approaches for DPI have been explored before using the programmable logic of field programmable gate arrays (FPGA) as a potential solution for NIDS approaches that would be power-suitable for IoT. However, those previous programmable logic NIDS approaches utilize either a supervised or unsupervised learning model. Sentinel utilizes the ensemble of these two machine learning approaches known as a semi-supervised approach which has shown promise in NIDS implementations. Sentinel provides a programmable logic implementation of a semi-supervised approach for DPI which operates at much lower power and latency than a GPU implementation with negligible loss of accuracy due to quantization through a logistic regressor.

Anderson, MatthewW [Idaho National Laboratory (INL↗

Hardware Evaluation Outreach: Application development Challenges Now and for the Exascale Era

The intent of this document is to assist the programmer in understanding details of contemporary and Exascale hardware system design and how these designs provide opportunities and place constraints on next-generation simulation software design. We attempt to clarify hardware organization and component details for our most current and Exascale systems to help program developers understand how software needs to change in order to take best advantage of the performance available. Exascale success is specifically defined for ECP as a 50x improvement over baseline in the aggregate "capability volume" on several KPP axes, of which raw floating point performance is only one, but also includes characteristics such as problem size, system memory size, node memory size, power, and efficiency. This multi-axis approach is particularly important to understand in the context of delivered improvements in real applications, since, for instance, the floating point computation may comprise less than 10% of the actual computational work required. Given the Exascale requirements and the constraints these requirements put on the performance expectations of fundamental system components, the programmer will be forced to re-think several application implementation details in order to achieve exaflop performance on these systems. The remainder of this document aims to present more detail on Exascale era system hardware and the specific areas that the programmer should address to extract performance from these systems. We attempt to give the programmer guidance at both a high- and low-level, providing some abstract suggestions on how to refactor codes given the expected system architectures and some low-level recommendations on how to implement these modifications. We also include a section on training resources that are helpful for both programmers that are just beginning to understand code modifications for contemporary and Exascale systems and for those that have done some refactoring and are now trying to extract maximal application performance from these systems.

97 MATHEMATICS AND COMPUTING↗

A Data Type for Efficient Representation of Other Data Types

A self-organizing, monomorphic data type denoted a sequence has been conceived to address certain concerns that arise in programming parallel computers. A sequence in the present sense can be regarded abstractly as a vector, set, bag, queue, or other construct. Heretofore, in programming a parallel computer, it has been necessary for the programmer to state explicitly, at the outset, what parts of the program and the underlying data structures must be represented in parallel form. Not only is this requirement not optimal from the perspective of implementation; it entails an additional requirement that the programmer have intimate understanding of the underlying parallel structure. The present sequence data type overcomes both the implementation and parallel structure obstacles. In so doing, the sequence data type provides unified means by which the programmer can represent a data structure for natural and automatic decomposition to a parallel computing architecture. Sequences exhibit the behavioral and structural characteristics of vectors, but the underlying representations are automatically synthesized from combinations of programmers advice and execution use metrics. Sequences can vary bidirectionally between sparseness and density, making them excellent choices for many kinds of algorithms. The novelty and benefit of this behavior lies in the fact that it can relieve programmers of the details of implementations. The creation of a sequence enables decoupling of a conceptual representation from an implementation. The underlying representation of a sequence is a hybrid of representations composed of vectors, linked lists, connected blocks, and hash tables. The internal structure of a sequence can automatically change from time to time on the basis of how it is being used. Those portions of a sequence where elements have not been added or removed can be as efficient as vectors. As elements are inserted and removed in a given portion, then different methods are utilized to provide both an access and memory strategy that is optimized for that portion and the use to which it is put.

James, Mark↗

Extreme Programming: Maestro Style

"Extreme Programming: Maestro Style" is the name of a computer programming methodology that has evolved as a custom version of a methodology, called extreme programming that has been practiced in the software industry since the late 1990s. The name of this version reflects its origin in the work of the Maestro team at NASA's Jet Propulsion Laboratory that develops software for Mars exploration missions. Extreme programming is oriented toward agile development of software resting on values of simplicity, communication, testing, and aggressiveness. Extreme programming involves use of methods of rapidly building and disseminating institutional knowledge among members of a computer-programming team to give all the members a shared view that matches the view of the customers for whom the software system is to be developed. Extreme programming includes frequent planning by programmers in collaboration with customers, continually examining and rewriting code in striving for the simplest workable software designs, a system metaphor (basically, an abstraction of the system that provides easy-to-remember software-naming conventions and insight into the architecture of the system), programmers working in pairs, adherence to a set of coding standards, collaboration of customers and programmers, frequent verbal communication, frequent releases of software in small increments of development, repeated testing of the developmental software by both programmers and customers, and continuous interaction between the team and the customers. The environment in which the Maestro team works requires the team to quickly adapt to changing needs of its customers. In addition, the team cannot afford to accept unnecessary development risk. Extreme programming enables the Maestro team to remain agile and provide high-quality software and service to its customers. However, several factors in the Maestro environment have made it necessary to modify some of the conventional extreme-programming practices. The single most influential of these factors is that continuous interaction between customers and programmers is not feasible.

Norris, Jeffrey↗

Efficient Multiplexer FPGA Block Structures Based on G4FETs

Generic structures have been conceived for multiplexer blocks to be implemented in field-programmable gate arrays (FPGAs) based on four-gate field-effect transistors (G(sup 4)FETs). This concept is a contribution to the continuing development of digital logic circuits based on G4FETs and serves as a further demonstration that logic circuits based on G(sup 4)FETs could be more efficient (in the sense that they could contain fewer transistors), relative to functionally equivalent logic circuits based on conventional transistors. Results in this line of development at earlier stages were summarized in two previous NASA Tech Briefs articles: "G(sup 4)FETs as Universal and Programmable Logic Gates" (NPO-41698), Vol. 31, No. 7 (July 2007), page 44, and "Efficient G4FET-Based Logic Circuits" (NPO-44407), Vol. 32, No. 1 ( January 2008), page 38 . As described in the first-mentioned previous article, a G4FET can be made to function as a three-input NOT-majority gate, which has been shown to be a universal and programmable logic gate. The universality and programmability could be exploited to design logic circuits containing fewer components than are required for conventional transistor-based circuits performing the same logic functions. The second-mentioned previous article reported results of a comparative study of NOT-majority-gate (G(sup 4)FET)-based logic-circuit designs and equivalent NOR- and NAND-gate-based designs utilizing conventional transistors. [NOT gates (inverters) were also included, as needed, in both the G(sup 4)FET- and the NOR- and NAND-based designs.] In most of the cases studied, fewer logic gates (and, hence, fewer transistors), were required in the G(sup 4)FET-based designs. There are two popular categories of FPGA block structures or architectures: one based on multiplexers, the other based on lookup tables. In standard multiplexer- based architectures, the basic building block is a tree-like configuration of multiplexers, with possibly a few additional logic gates such as ANDs or ORs. Interconnections are realized by means of programmable switches that may connect the input terminals of a block to output terminals of other blocks, may bridge together some of the inputs, or may connect some of the input terminals to signal sources representing constant logical levels 0 or 1. The left part of the figure depicts a four-to-one G(sup 4)FET-based multiplexer tree; the right part of the figure depicts a functionally equivalent four-to-one multiplexer based on conventional transistors. The G(sup 4)FET version would contains 54 transistors; the conventional version contains 70 transistors.

Vatan, Farrokh↗

Methods and circuitry for reconfigurable SEU/SET tolerance

A device is disclosed in one embodiment that has multiple identical sets of programmable functional elements, programmable routing resources, and majority voters that correct errors. The voters accept a mode input for a redundancy mode and a split mode. In the redundancy mode, the programmable functional elements are identical and are programmed identically so the voters produce an output corresponding to the majority of inputs that agree. In a split mode, each voter selects a particular programmable functional element output as the output of the voter. Therefore, in the split mode, the programmable functional elements can perform different functions, operate independently, and/or be connected together to process different parts of the same problem.

Shuler, Jr., Robert L.↗

Astro-animation - A case study of art and science education

Art and science are different ways of exploring the world, but together they have the potential to be thought-provoking, facilitate a science‐society dialogue, raise public awareness of science and develop an understanding of art. For several years, we have been teaching an astro-animation class at the Maryland Institute College of Art as a collaboration between students and NASA scientists. Working in small groups, the students create short animations based on the research of the scientists who are going to follow the projects as mentors. By creating these animations, students bring the power of their imagination to see the research of the scientists through a different lens. Astro-animation is an undergraduate-level course jointly taught by an astrophysicist and an animator. In this article, we present the motivation behind the class, describe the details of how it is carried out and discuss the interactions between artists and scientists. We describe how such a programme offers an effective way for art students, not only to learn about science but to have a glimpse of ‘science in action’. The students have the opportunity to become involved in the process of science as artists, as observers first and potentially through their own art research. Every year, one or more internships at NASA Goddard Space Flight Center have been available for our students in the summer. Two students describe their experiences undertaking these internships and how science affects their creation of animations for this programme and in general. We also explain the genesis of our astro-animation programme, how it is taught in our animation department and we present the highlights of an investigation of the effectiveness of this programme we carried out with the support of an NEA research grant. In conclusion, we discuss how the programme may grow in new directions, such as contributing to informal STE(A)M learning.

Laurence Arcadias↗

A Model from the Mind to the Operating Facility - 16448

The reprocessing of Spent Magnox fuel has been undertaken at the Sellafield site in the United Kingdom (UK) for more than 50 years and is now entering the final few years of its operating programme. The age of this facility has resulted in additional operational challenges which have led to the need for a sustained programme of continuous improvement. It has therefore been necessary to assess what potential plant improvements are key to delivering a successful end to the operating programme. In 2003 the UK National Nuclear Laboratory (NNL) (then Nexia Solutions) worked with Sellafield Ltd to produce a visual discrete event simulation (DES) model. The DES approach models plant equipment (such as a storage pond crane or fuel element processing equipment), and the key processes that these items undertake. Process times, availability and process logic are all combined to provide a prediction of the plant performance. Through the use of 'what-if' scenarios, changes to any model parameter can be undertaken. The benefits of such an approach have been in the ability for Sellafield Ltd to understand which changes to make and which do not add value. This then allows the operating facility to focus the improvement programme on quantitatively underpinned benefits, thus increasing the potential to complete the reprocessing programme ahead of schedule, which is a key aim for Sellafield Ltd. Maximising the benefit of this model has required a close working relationship between NNL, Sellafield Ltd Technical and the Sellafield Ltd Operations teams to ensure that the model is using the correct information and is addressing the real issues at hand. Over the past 12 years many ideas have been assessed and three examples have been selected to demonstrate the range of use of the model, and the different approaches used to identify issues and opportunities, agree an approach and provide solutions. (authors)

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Fit for Purpose Remote Technology Decommissioning Solutions - 18630

The Magnox Decommissioning Project is actively progressing clean-up and decommissioning of 12 reactor sites across England, Scotland and Wales. Funded and directed by the United Kingdom's Nuclear Decommissioning Authority (NDA) and managed by the Cavendish Fluor Partnership (CFP), the Magnox Decommissioning Project introduces a wide range of radiological and industrial hazards warranting deployment of remote technologies to safely de-inventory, decontaminate and decommission a vast array of nuclear facilities. The Magnox Decommissioning Project encompasses 22 former Magnox nuclear power production reactors across 10 reactor sites and five research/test reactors at two former research sites. Decommissioning activities have been underway at some sites for nearly 20 years with early focus on retrieving and stabilising wastes and draining and stabilising spent fuel ponds. The Magnox decommissioning strategy invokes a programme perspective to drive consistency in tackling similar decommissioning and waste challenges across multiple sites. Programme central teams have worked with technology suppliers to foster learning from industry experience to develop and deploy tooling and robotics. The programme approach has also facilitated learning from one site to the next. In many cases, this central programme approach has promoted an evolution of technologies resulting in optimisation of simple remote tooling. In other instances, collaboration with suppliers is producing state-of-the-art technologies to tackle more unique challenges including, most recently, early demonstration of laser cutting for reactor vessel dismantling. This paper will outline the programme management approach and the scalable optioneering process Magnox employs to select the engineered controls and technologies used in decommissioning and waste management activities. It will provide an overview of the broad range of remote tooling and robotics deployed across the 12 Magnox sites by exploring some specific examples. Lastly, the paper will summarise key lessons learned in the now extensive history of selecting and using remote technologies to decommission Magnox nuclear facilities. (authors)

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Industry overview of TRANSCEND - 20271

The United Kingdom has a legacy of nuclear facilities to decommission and radioactive waste to manage and dispose of. The TRANSCEND programme is an independent research programme with significant participation from industrial organizations that are involved in that decommissioning programme and radioactive waste management. The participation has led to a programme that is both academically robust enough to attract significant funding from the EPSRC, the universities themselves and relevant enough to be supported financially by the industrial partners who see the needs and drivers. The programme offers benefits in terms of the development of people and in enabling and promoting innovation in both hardware and software tools. Industrial engagement is fundamental to being able to capitalise on that innovation. (authors)

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Assessment of work-integrated learning: comparison of the usage of a grading rubric by supervising radiographers and teachers

Introduction: Professional work-integrated learning (WIL) that integrates the academic experience with off-campus professional experience placements is an integral part of many tertiary courses. Issues with the reliability and validity of assessment grades in these placements suggest that there is a need to strengthen the level of academic rigour of placements in these programmes. This study aims to compare the attitudes to the usage of assessment rubrics of radiographers supervising medical imaging students and teachers supervising pre-service teachers. Methods: WIL placement assessment practices in two programmes, pre-service teacher training (Avondale College of Higher Education, NSW) and medical diagnostic radiography (Faculty of Health Sciences, University of Sydney, NSW), were compared with a view to comparing assessment strategies across these two different educational domains. Educators (course coordinators) responsible for teaching professional development placements of teacher trainees and diagnostic radiography students developed a standards-based grading rubric designed to guide assessment of students’ work during WIL placement by assessors. After ∼12 months of implementation of the rubrics, assessors’ reaction to the effectiveness and usefulness of the grading rubric was determined using a specially created survey form. Data were collected over the period from March to June 2011. Quantitative and qualitative data found that assessors in both programmes considered the grading rubric to be a vital tool in the assessment process, though teacher supervisors were more positive about the benefits of its use than the radiographer supervisors. Results: Benefits of the grading rubric included accuracy and consistency of grading, ability to identify specific areas of desired development and facilitation of the provision of supervisor feedback. The use of assessment grading rubrics is of benefit to assessors in WIL placements from two very different teaching programmes. Conclusion: Radiographers appear to need more training in the rubric's use, whereas teachers are found to generally use it appropriately. There are implications drawn from this finding that are applicable to health science and medical education in general.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

A Global View Programming Abstraction for Transitioning MPI Codes to PGAS Languages

The multicore generation of scientific high performance computing has provided a platform for the realization of Exascale computing, and has also underscored the need for new paradigms in coding parallel applications. The current standard for writing parallel applications requires programmers to use languages designed for sequential execution. These languages have abstractions that only allow programmers to operate on the process centric local view of data. To provide suitable languages for parallel execution, many research efforts have designed languages based on the Partitioned Global Address Space (PGAS) programming model. Chapel is one of the more recent languages to be developed using this model. Chapel supports multithreaded execution with high-level abstractions for parallelism. With Chapel in mind, we have developed a set of directives that serve as intermediate expressions for transitioning scientific applications from languages designed for sequential execution to PGAS languages like Chapel that are being developed with parallelism in mind.

Global Domain↗

Cross-border cooperation in inner Scandinavia: A territorial impact assessment

The use of territorial impact assessment procedures is gaining increasing relevance in the European Union policy evaluation processes. However, no concrete territorial impact assessment tools have been applied to evaluating EU cross-border programmes. In this light, this article provides a pioneering analysis on how to make use of territorial impact assessment procedures on cross-border programmes. More specifically, it assesses the main territorial impacts of the Inner Scandinavian INTERREG-A sub-programme, in the last 20 years (1996–2016). It focuses on its impacts on reducing the barrier effect, in all its main dimensions, posed by the presence of the administrative border. The results indicate a quite positive impact of the analysed cross-border cooperation programme, in reducing the barrier effect in all its main dimensions. The obtained potential impact values for each analysed dimension indicate, however, that the ‘economy-technology’ dimension was particularly favoured, following its strategic intervention focus in stimulating the economic activity and the attractiveness of the border area. - Highlights: • A territorial impact assessment method to assess cross-border cooperation is proposed. • This method rationale is based on the main dimensions of the barrier effect. • This method identified positive impacts in all analysed dimensions. • The economy-technological dimension was the most positively impacted one.

54 ENVIRONMENTAL SCIENCES↗

An application of the theory of planned behaviour to study the influencing factors of participation in source separation of food waste

Highlights: ► Theory of planned behaviour (TPB) has been conducted to identify the influencing factors for participation in source separation of food waste using self administered questionnaires. ► The findings suggested several implications for the development and implementation of waste separation at home programme. ► The analysis indicates that the attitude towards waste separation is determined as the main predictors where this in turn could be a significant predictor of the repondent’s actual food waste separation behaviour. ► To date, none of similar have been reported elsewhere and this finding will be beneficial to local Authorities as indicator in designing campaigns to promote the use of waste separation programmes to reinforce the positive attitudes. - Abstract: Tremendous increases in biodegradable (food waste) generation significantly impact the local authorities, who are responsible to manage, treat and dispose of this waste. The process of separation of food waste at its generation source is identified as effective means in reducing the amount food waste sent to landfill and can be reused as feedstock to downstream treatment processes namely composting or anaerobic digestion. However, these efforts will only succeed with positive attitudes and highly participations rate by the public towards the scheme. Thus, the social survey (using questionnaires) to analyse public’s view and influencing factors towards participation in source separation of food waste in households based on the theory of planned behaviour technique (TPB) was performed in June and July 2011 among selected staff in Universiti Putra Malaysia, Serdang, Selangor. The survey demonstrates that the public has positive intention in participating provided the opportunities, facilities and knowledge on waste separation at source are adequately prepared by the respective local authorities. Furthermore, good moral values and situational factors such as storage convenience and collection times are also encouraged public’s involvement and consequently, the participations rate. The findings from this study may provide useful indicator to the waste management authorities in Malaysia in identifying mechanisms for future development and implementation of food waste source separation activities in household programmes and communication campaign which advocate the use of these programmes.

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Tuning Molecular Interactions between Peptoids and Substrates to Achieve Surface-Agnostic Coating

Achieving programmable and robust coatings that maintain functionality while adhering to various surface types with molecular-level tunability and programmable features remains challenging. In this study, we develop adaptable and stable surface-agnostic coatings (SACs) based on crystalline peptoid membranes by tuning interpeptoid and peptoid-substrate interactions. We utilize two complementary methods: (1) surfaceinduced assembly, where peptoid membranes form directly on substrates, and (2) depositing preformed peptoid crystalline membranes via an aqueous layer-by-layer (LbL) assembly technique. These strategies are applied to substrates with diverse surface chemistries and topographies, including mica, highly ordered pyrolytic graphite (HOPG), MoS 2 , sapphire, and porous membranes like porous alumina and polysulfide. Atomic force microscopy confirms the formation of peptoid coatings and reveals differences in assembly behavior across surfaces. Moisture vapor transport measurements serve as a proof-of-concept test for membrane continuity and tunable permeance. Together, these findings demonstrate the adaptability and programmability of peptoid-based SACs, enabling rational coating design on surfaces with diverse chemical and topographical features. Furthermore, this work opens pathways for using peptoid membranes as programmable surface modifiers in functional interfaces, protective coatings, and membrane platforms.

biomimetic polymers↗

Revealing the structure of light pseudoscalar mesons at the electron–ion collider

The questions of how the bulk of the Universe's visible mass emerges and how it is manifest in the existence and properties of hadrons are profound, and probe the heart of strongly interacting matter. Paradoxically, the lightest pseudoscalar mesons appear to be key to a further understanding of the emergent mass and structure mechanisms. These mesons, namely, the pion and kaon, are the Nambu-Goldstone boson modes of quantum chromodynamics (QCD). Unravelling their partonic structure and the interplay between emergent and Higgs-boson mass mechanisms is a common goal of three interdependent approaches - continuum QCD phenomenology, lattice-regularised QCD, and the global analysis of parton distributions - linked to experimental measurements of hadron structure. Experimentally, the anticipated electron-ion collider will enable a revolution in our ability to study pion and kaon structures, accessed by scattering from the 'meson cloud' of the proton through the Sullivan process. With the goal of enabling a suite of measurements that can address these questions, we examine key reactions that identify the critical detector-system requirements needed to map tagged pion and kaon cross-sections over a wide range of kinematics. The excellent prospects for extracting pion structural, functional, and form-factor data are outlined, and similar prospects for kaon structures are discussed in the context of a worldwide programme. Finally, the successful completion of the programme outlined herein will deliver deep, far-reaching insights into the emergence of pions and kaons, their properties, and their role as QCD's Goldstone boson modes.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗