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The role of Aspo Hard Rock laboratory for the Swedish nuclear fuel and waste management's research, developing and demonstration programme for a final repository of spent nuclear fuel - 15378

The Aspo Hard Rock Laboratory (HRL), located in the Simpevarp area in the municipality of Oskarshamn in Sweden, Figure 1, constitutes an important part of the Swedish Nuclear Fuel and Waste Management (SKB) work with design and construction of a deep geological repository for final disposal of spent nuclear fuel. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create an opportunity for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. Most of the research has concerned with processes of importance for the long-term safety of a future final repository and the capability to model the processes taking place at repository depth. Demonstration addresses the performance of the engineered barriers and practical means of constructing a repository and emplacing the canisters containing spent fuel. SKB will in the coming years more focus on using the Aspo HRL for demonstrating technology for and function of important parts of the repository system before constructing and operate the spent nuclear fuel repository in Forsmark. Aspo HRL includes both a research village with office space for 100 persons and different laboratories, e.g. Chemistry and Material Science Laboratory and Bentonite Laboratory, and an underground research laboratory to a depth of 460 m. The Aspo HRL is also open for other organisations to be used for their own projects and experiments not only related to nuclear waste management research. (authors)

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The Bukov underground research facility as part of the Czech Republic's DGR development programme - 15644

The Czech Republic's deep geological repository (DGR) policy sets out a number of important milestones including the selection of candidate sites by 2018 and the selection of a final site by 2025. The final commissioning of the Czech DGR is planned for 2065. In 2010 a screening process was completed employing geological and other criteria that resulted in the identification of 7 potentially suitable sites, all situated in crystalline - granite host rock environments. The next step of the process will result in a reduction both in the number of sites and the surface area of remaining sites based on preliminary safety evaluations and socioeconomic, political and environmental criteria. In order to better understand the behaviour of crystalline host rock environments for DGR safety case purposes, the Radioactive Waste Repository Authority (RAWRA) made decided to enhance the extent of in-situ measurements and research at a depth corresponding to that of the future DGR. In the second half of 2013, RAWRA commenced the construction of the Bukov Underground Research Facility (Bukov URF) in the southern section of the Rozna uranium mine at a depth of 600 m below the earth's surface in a geologically well-mapped area of a Moldanubic crystalline rock formation which is composed principally of migmatised gneisses, migmatites and granulites. The Bukov URF will be, first and foremost, a research facility at which work will be conducted focusing on the taking of geophysical measurements, petrographic, mineralogic, geochemical research and the in-situ determination of the physical - mechanical, geochemical and hydrogeological properties of the host rock massif. The research results will form input data which will be used to both support and improve the safety of the future DGR. (authors)

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Initial report from the ICFA Neutrino Panel

The discovery of neutrino oscillations implies that neutrinos have mass and that the flavour eigenstates mix. Non-zero neutrino masses require new physics beyond the Standard Model. Revealing the physics behind neutrino masses and mixing is among the highest priorities for particle physics in the twenty-first century. Measurements of the parameters that govern neutrino oscillations will have a profound impact on our understanding of particle physics, astrophysics and cosmology. Such a breadth of impact justifies a far-reaching experimental programme by which the properties of the neutrino that are presently unknown are determined, the three-neutrino-mixing picture is tested and the properties of the neutrino are measured with a precision sufficient to allow the physics that explains these properties to be understood. Accelerator-based neutrino-oscillation experiments are an essential component of this programme as they are the only way in which oscillations between all known flavours can be studied precisely. The accelerator-based neutrino-oscillation programme is international in both scope and engagement. The approved programme will improve our knowledge of the mixing angles and the mass-squared differences and may be able to determine the neutrino mass hierarchy. In the medium term, the Long-baseline Neutrino Experiment (LBNE) and the Tokai (J-PARC) to Hyper-Kamiokande experiment offer complementary approaches to searching for the violation of the matter-anti-matter symmetry in neutrino oscillations. For these experiments to realise their full potential coordinated programmes of hadro-production and neutrino-nucleus cross-section measurements are essential. A design study of an alternative wide-hand beam facility is underway: the Long-baseline Neutrino Observatory (LBNO) study will report by the end of 2014. New concepts such as the implementation of a neutrino beam on the European Spallation Source (ESSnuSB) and the use of muon decay-at-rest to search for the matter-anti-matter asymmetry (Daedalus) are also being studied. The Neutrino Factory, in which electron- and muon-neutrino beams are produced from the decay of muons confined within a storage ring, has been shown to offer the ultimate sensitivity and precision. The staged implementation of the facility has been studied. The attractive hrst stage, “nuSTORM”, has the potential to make detailed and precise studies of electron- and muon-neutrino-nucleus scattering and to make exquisitely sensitive searches for sterile neutrinos. A small number of measurements do not fit the elegant three-neutrino-mixing model. These measurements can be interpreted as evidence for new “sterile neutrino” states. If confirmed, these measurements will revolutionise the held. An experimental programme is underway to investigate these anomalies. It is important that these anomalies are addressed. Short-baseline contributions to this programme should have clear synergy with the long-baseline programme. This report presents the conclusions drawn by the Panel from three regional “Town Meetings” that took place between November 2013 and February 2014. The Panel recognises that to maximise the discovery potential of the accelerator-based neutrino-oscillation programme it will be essential to exploit the infrastructures that exist at CERN, FNAL and J-PARC and the expertise and resources that reside in laboratories and institutes around the world.

Cao, J.↗

Overcoming the barriers to implementation of decommissioning and environmental remediation projects, the CIDER project - 15160

Much remains to be done in terms of addressing the legacies from the early development of nuclear energy, including the dismantling of redundant research and fuel cycle facilities, research reactors, and power plants, and the remediation of sites affected by past uranium mining and processing operations. Long-term solutions still need to be found for management of the resulting waste, including development of disposal facilities that meet public acceptance and safety requirements. Some countries are moving forward with dealing with these legacies, and accordingly have built up appropriate technical resources and expertise, but many national programmes still face very significant challenges. Many are the factors that constrain progress in addressing past legacies. It is recognized the importance of early implementation of decommissioning and environmental remediation (D and ER) programmes in order to safeguard people and the environment from the undesirable effects of ionizing radiation and other hazards associated with these sites. There is also an urgent need to better understand the global status of these activities and to establish mechanisms to analyze and report the barriers impeding the implementation of D and ER programmes, with the aim of outlining actions that may improve the current situation. The IAEA has thus launched the CIDER Project (Constraints to Implementing Decommissioning and Environmental Remediation) with the broad aim of contributing to improve current levels of performance on D and ER programmes through promoting greater cooperation amongst its Member States and relevant international organizations. This paper provides early results from the first phase of the project. During this phase, a survey on the global situation of D and ER was undertaken in order to better understand why these programmes proceed faster in some countries than in others; to identify major constraining factors that affect the implementation of D and ER programmes and how these impediments might be overcome. The paper aims to address policy-level issues, regulatory aspects, technological aspects, and stakeholder involvement in the decision-making process. In the next phase of the project it is intended that specific actions and/or innovative approaches will be proposed at international, regional, or national levels with the goal of facilitating progress in programme implementation. (authors)

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A novel digital pulse processing architecture for nuclear instrumentation

The field of nuclear instrumentation covers a wide range of applications, including counting, spectrometry, pulse shape discrimination and multi-channel coincidence. These applications are the topic of many researches, new algorithms and implementations are constantly proposed thanks to advances in digital signal processing. However, these improvements are not yet implemented in instrumentation devices. This is especially true for neutron-gamma discrimination applications which traditionally use charge comparison method while literature proposes other algorithms based on frequency domain or wavelet theory which show better performances. Another example is pileups which are generally rejected while pileup correction algorithms also exist. These processes are traditionally performed offline due to two issues. The first is the Poissonian characteristic of the signal, composed of random arrival pulses which requires to current architectures to work in data flow. The second is the real-time requirement, which implies losing pulses when the pulse rate is too high. Despite the possibility of treating the pulses independently from each other, current architectures paralyze the acquisition of the signal during the processing of a pulse. This loss is called dead-time. These two issues have led current architectures to use dedicated solutions based on re-configurable components like Field Programmable Gate Arrays (FPGAs) to overcome the need of performance necessary to deal with dead-time. However, dedicated hardware algorithm implementations on re-configurable technologies are complex and time-consuming. For all these reasons, a programmable Digital pulse Processing (DPP) architecture in a high level language such as Cor C++ which can reduce dead-time would be worthwhile for nuclear instrumentation. This would reduce prototyping and test duration by reducing the level of hardware expertise to implement new algorithms. However, today's programmable solutions do not meet the need of performance to operate online and not allow scaling with the increase in the number of measurement channel. That is why an innovative DPP architecture is proposed in this paper. This architecture is able to overcome dead-time while being programmable and is flexible with the number of measurement channel. Proposed architecture is based on an innovative execution model for pulse processing applications which can be summarized as follow. The signal is not composed of pulses only, consequently, pulses processing does not have to operate on the entire signal. Therefore, the first step of our proposal is pulse extraction by the use of dedicated components named pulse extractors. The triggering step can be achieved after the analog-to-digital conversion without any signal shaping or filtering stages. Pileup detection and accurate pulse time stamping are done at this stage. Any application downstream this step can work on adaptive variable-sized array of samples simplifying pulse processing methods. Then, once the data flow is broken, it is possible to distribute pulses on Functional Units (FUs) which perform processing. As the date of each pulse is known, they can be processed individually out-of-order to provide the results. To manage the pulses distribution, a scheduler and an interconnection network are used. pulses are distributed on the first FU which is not busy without congesting the interconnection network. For this reason, the process duration does not result anymore in dead-time if there are enough FUs. FUs are designed to be standalone and to comprises at least a programmable general purpose processor (ARM, Microblaze) allowing the implementation of complex algorithms without any modification of the hardware. An acquisition chain is composed of a succession of algorithms which lead to organize our FUs as a software macro-pipeline, A simple approach consists in assigning one algorithm per FU. Consequently, the global latency becomes the worst latency of algorithms execution on FU. Moreover, as algorithms are executed locally - i.e. on a FU - this approach limits shared memory requirement. To handle multichannel, we propose FUs sharing, this approach maximize the chance to find a non-busy FU to process an incoming pulse. This is possible since each channel receive random event independently, the pulse extractors associated to them do not necessarily need to access simultaneously to all Computing resources at the same time to distribute their pulses. The major contribution of this paper is the proposition of an execution model and its associated hardware programmable architecture for digital pulse processing that can handle multiple acquisition channels while maintaining the scalability thanks to the use of shared resources. This execution model and associated architecture are validated by simulation of a cycle accurate architecture SystemC model. Proposed architecture shows promising results in terms of scalability while maintaining zero dead-time. This work also permit the sizing of hardware resources requirement required for a predefined set of applications. Future work will focus on the interconnection network and a scheduling policy that can exploit the variable-length of pulses. Then, the hardware implementation of this architecture will be performed and tested for a representative set of application.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Designing Crane Controls with Applied Mechanical and Electrical Safety Features

The use of overhead traveling bridge cranes in many varied applications is common practice. In particular, the use of cranes in the nuclear, military, commercial, aerospace, and other industries can involve safety critical situations. Considerations for Human Injury or Casualty, Loss of Assets, Endangering the Environment, or Economic Reduction must be addressed. Traditionally, in order to achieve additional safety in these applications, mechanical systems have been augmented with a variety of devices. These devices assure that a mechanical component failure shall reduce the risk of a catastrophic loss of the correct and/or safe load carrying capability. ASME NOG-1-1998, (Rules for Construction of Overhead and Gantry Cranes, Top Running Bridge, and Multiple Girder), provides design standards for cranes in safety critical areas. Over and above the minimum safety requirements of todays design standards, users struggle with obtaining a higher degree of reliability through more precise functional specifications while attempting to provide "smart" safety systems. Electrical control systems also may be equipped with protective devices similar to the mechanical design features. Demands for improvement of the cranes "control system" is often recognized, but difficult to quantify for this traditionally "mechanically" oriented market. Finite details for each operation must be examined and understood. As an example, load drift (or small motions) at close tolerances can be unacceptable (and considered critical). To meet these high functional demands encoders and other devices are independently added to control systems to provide motion and velocity feedback to the control drive. This paper will examine the implementation of Programmable Electronic Systems (PES). PES is a term this paper will use to describe any control system utilizing any programmable electronic device such as Programmable Logic Controllers (PLC), or an Adjustable Frequency Drive (AID) 'smart' programmable motion controller. Therefore the use of the term Programmable Electronic Systems (PES) is an encompassing description for a large spectrum of programmable electronic control devices.

Lytle, Bradford P.↗

Costs and benefits of a school-based health intervention in Portugal

Abstract School-based programmes for preventing childhood obesity have been shown to be effective in improving eating habits and nutritional status, but few intervention programmes with a controlled design have included an economic evaluation. In this study, we conducted a cost-consequence analysis to evaluate the costs and the health benefits of the ‘Planning Health in School’ programme (PHS-pro) implemented in the Northern region of Portugal to 449 children of 10–14 years old. Previous study has showed that after PHS-pro, several anthropometric measures significantly improved in the intervention group (height, waist circumference and waist-height ratio) compared with the control group, followed by significant improvements on soft drinks, fruit and vegetables daily consumptions. Costs were estimated according the two phases of the programme: designing and preparation of schools, and school setting implementation, and included all the direct costs on human and material resources. PHS-pro total costs were estimated as 7915.53€/year with an intervention cost of 36.14€/year/child attending the programme. This is much lower than the direct costs for treating an obese adult in Portugal, which was calculated as 3849.15€/year. A scale-up costing projection for implementing the PHS-pro to a larger young population was estimated to be even lower: 18.18€/year/child. This cost-consequence analysis provided evidence that the PHS-pro was economically feasible especially if compared with the medical costs for treating adult obesity. The PHS-pro can be a beneficial investment and may give a promising contribution to addressing overweight over childhood and adolescence, which are developmental stages that determine adulthood chronic diseases.

Vieira, Margarida↗

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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