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Working in partnership with the UK nuclear industry to package waste - 16263

Radioactive Waste Management (RWM) is a wholly owned subsidiary of the Nuclear Decommissioning Authority (NDA), which is responsible for managing the effective clean-up of the UK's nuclear legacy. RWM is responsible for delivering a geological disposal facility and providing radioactive waste management solutions. To this end, RWM provides advice to waste owners to help them retrieve, condition and package waste now in ways that make them suitable for disposal later. To facilitate planning decisions and hazard reduction, RWM operates the Disposability Assessment process. This is used to provide advice to waste producing organisations on approaches to waste packaging and interim storage of packaged wastes. This advice is intended to ensure compatibility with future geological disposal requirements, as far as this is possible in advance of the availability of Waste Acceptance Criteria for a Geological Disposal Facility (GDF). As such, it is an enabler for early hazard reduction on UK nuclear sites through the facilitation of packaging. This paper explains how RWM is working with waste owners through the Disposability Assessment process to deliver optimised waste packaging solutions through proactive and early engagement. This includes specific examples of how the process has been used in a flexible way to contribute to accelerated and sustainable hazard reduction at UK sites using a partnership approach. (authors)

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Analysis of Legacy {sup 85}Kr Waste Form Samples - 16319

In the late 1970's, the Idaho Chemical Processing Plant conducted an R and D program on krypton encapsulation. Legacy samples composed of {sup 85}Kr incorporated in solid zeolite 5A material, and five small metal tubes containing a mixture of the zeolite combined with a glass matrix resulting from hot isostatic pressing, have been preserved. These samples were shipped to Oak Ridge National Laboratory (ORNL) in mid-FY 2014. After receipt and repackaging, the samples were examined by x-ray imaging and x-ray tomography. Two of the capsules appear to contain an amorphous mass within the capsules. An image of one capsule clearly shows the saw marks on the capsule and a quantity of loose pellet or bead-like material remaining in the capsule. An image of another capsule shows similar bead-like material within the intact capsule. One of the capsules was previously opened. The end of this capsule appears to have been cut off, and there are additional saw marks on the side of the capsule. X-ray tomography allowed the capsules to be viewed along the three axes. Of most interest was determining whether there was any residual material in the closed end of this capsule. The images confirmed the presence of residual material within this capsule. The material appears to be compacted but still retains some of the bead-like morphology. Based on the initial nondestructive assay (NDA) and the fact that there are two obviously breached samples, a plan was developed for exploratory tests that would be conducted with the breached specimens before opening the three intact capsules. Preparations are being made to determine the fraction of krypton/xenon remaining in the waste form matrix and the amount of rubidium remaining in the waste form matrix. The inner surface of the breached capsules will be examined for corrosion. (authors)

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GrayQb Single-Faced Version 2 Open Environment Test - 16344

The GrayQb{sup TM} Single Faced Version 2 (SF2) is a non-destructive examination device developed to generate radiation contour maps showing source locations and relative radiological levels present in an area under examination. This device allows for characterization of radioactively contaminated areas such as hot cells, gloveboxes, small and large rooms, hallways, and waste tanks. The goal of GrayQb{sup TM} (pronounced 'Gray Cube') is to provide a low cost easily deployable device to aid in the process of decontamination and decommissioning (D and D). The GrayQb{sup TM} SF2 device is approximately a six inch cube weighing seven (7) pounds composed of a tungsten shield with integrated collimator, radiation imaging medium (Phosphor Storage Plate), and digital camera. This paper details the design upgrades incorporated into the new version of the GrayQb{sup TM} SF2 device and the characterization testing of this upgraded device. Device results from controlled testing performed at the Savannah River Site (SRS) Health Physics Instrument Calibration Laboratory (HPICL) are presented, as well as results from the open environment field testing performed in the E-Area Low Level Waste Storage Area. Follow on work performed deploying the GrayQb SF2 device at the Hanford Plutonium Reclamation Facility (PRF) to assist in the radiological characterization of the canyon will also be presented. Testing of the redesigned GrayQb{sup TM} SF2 device demonstrated its ability to detect low energy isotopes, e.g. Am-241 and Pu-238, not only indoors in controlled environments with well-defined source locations, but also in open environment field areas with a significant high energy background. Additionally, it was demonstrated that the device could detect higher energy isotopes (Cs-137 and Co-60) in a controlled setting and with additional testing and/or modifications to device and software, would likely be able to detect these isotopes in the open environment field testing. Follow on 2015 work performed at Hanford proved GrayQb to be a useful tool in the radiological characterization of the PRF canyon. Distribution tendencies of the radiological hot spots were identified that provided insights which will assist in more efficient planning of the continued D and D effort. Hot spots were identified which can be targeted during the future D and D effort and used as markers during the NDA assessment to quantify the radiological environment. (authors)

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Status Update - Installation and Operation of GeoMelt{sup R} ICV{sup TM} Process in the NNL's Central Laboratory on the Sellafield Site - 16410

Thermal treatment of nuclear waste in the UK has seen much renewed interest recently, owing to the advantages that can be gained in terms of reduced waste volumes, compatibility with reactive metals and organics and its ability to treat mixed generic wastes. Vitrification is a treatment option which destroys organics and some hazardous inorganics such as asbestos, reduces wasteform volume, and produces a robust leach resistant wasteform. Kurion's GeoMelt{sup R} In-Container Vitrification (ICV){sup TM} is a vitrification process where the treatment vessel can serve as an interim-storage, transport, and final long-term storage vessel - thus negating the need to pour glass into a separate container, effectively leading to a much simpler system than traditional waste melters. The UK's National Nuclear Laboratory (NNL) and Kurion have entered into a joint project to deploy an active waste ICV{sup TM} plant based on Kurion's GeoMelt{sup R} technology, at NNL's flagship Central Laboratory on the Sellafield site. NNL is the UK's national laboratory for civil nuclear science and technology, providing advice to government, protecting key skills, supporting industry and delivering national nuclear programs. NNL is bringing the Kurion GeoMelt{sup R} process alongside its existing capabilities in thermal waste treatment. Kurion provides technology solutions to minimize and stabilize nuclear and hazardous waste through its families of technologies: access, separation and stabilization processes. The GeoMelt{sup R} plant being installed at the NNL's Central Laboratory creates a platform to evaluate the vitrification technology for the variety of wastes from the NDA estate and creates a treatment path for problematic waste streams that currently have no disposition pathway. With the diverse facilities under NNL management coupled with the NNL's ability to import wastes from within the UK and Europe, this arrangement with Kurion provides waste owners with treatment disposition pathways for problematic wastes. The Kurion / NNL team completed non-radioactive commissioning of a GeoMelt{sup R} ICV{sup TM} treatment system in 2015. Commissioning consisted of performing two tests at NNL's Workington Laboratory. Commissioning Test 1 involved vitrification of 367 kg of glass frit over the course of approximately 18 hours. Commissioning Test 2 consisted of processing 470 kg of soil and additives in approximately 27 hours. The soil processed in the second test was non-radioactive soil from Sellafield and was used as an analog for radioactive soil to be processed during radioactive commissioning at the Central Laboratory at Sellafield. All commissioning test goals were easily achieved and all subsystems operated as designed. Radioactive commissioning will be carried out in early 2016. (authors)

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Innovative Waste Packaging and Associated Venting/Hydrogen Management - 16594

The original strategy for managing intermediate level waste (ILW) was developed in the 1980s by the UK Nuclear Industry Radioactive Waste Executive (NIREX), which is now the Radioactive Waste Management Limited (RWM), a wholly owned subsidiary of the Nuclear Decommissioning Authority (NDA). The strategy involved retrieving ILW, sorting and encapsulating it in cement based grout within thin walled stainless steel containers. The containers would then be transferred to a large purpose-built shielded ILW store on site, where they would be stored until the planned final deep geological disposal facility becomes available. In recognition of the high up-front costs of such a strategy, which requires remote facilities for the encapsulation and storage, and coupled with the long programme duration for the design, construction and commissioning of these facilities, waste management organisations responsible for managing the clean-up of legacy facilities within the UK have, in recent years, sought innovative solutions which could potentially both accelerate clean-up and hazard reduction on sites, and with a lower overall programme lifecycle cost. Many of the recent innovative solutions are focused around a new family of packaging designs known as robust shielded containers (RSCs). These are self-shielded containers manufactured from materials such as ductile cast iron or fabricated steel. These containers offer the potential to package wastes for disposal without encapsulation and avoid the need for a highly engineered remote handled shielded store for interim storage. The paper provides a high level overview of the generic concepts of RSCs developed by Croft and focuses on the specific challenges of wasteform evolution on waste package integrity and performance. In particular, the integrity and performance of the filtered vent system required to manage internal pressurisation and to ensure sufficient venting capacity of hydrogen and other evolved gases. The paper summarises the analysis by ARUP undertaken to substantiate the RSC integrity under detonation/deflagration explosion loadings arising from hydrogen accumulation. Analyses of the structural response of the filter assembly were undertaken for both detonation and deflagration explosion scenarios, with the loadings applied to the filter housing rim and to the filter vent cover. The paper also presents evidence of the mechanical performance of the filter medium in terms of pressure transients during deflagration events and the degree to which filtration efficiency is maintained. (authors)

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International Governmental Collaboration on Best Practice in Aging Infrastructure Management - 18027

Legacy nuclear sites in the US, UK and Canada are all facing a similar challenge of completing their operational and cleanup missions in parallel in a safe, efficient and cost-effective manner. Compounding the challenge is the fact that many important facilities are old with a significant level of deferred maintenance/capital needs, resulting in the need for a strategic approach to infrastructure management to ensure that maintenance and capital funding is directed at the highest priority items and that neither operations nor ongoing Decontamination and Decommissioning (D and D) activities are compromised. To help address this challenge, a Technical Information Exchange meeting was held in Ottawa, Canada in early June 2017 which brought together responsible parties from; - Government agencies including the UK Nuclear Decommissioning Authority (NDA), US Department of Energy Environmental Management (DOE EM), US National Nuclear Security Administration (NNSA), Atomic Energy of Canada Ltd (AECL) and Canadian Department of Defense - Implementers and other Government entities including Savannah River National Laboratory, Idaho National Laboratory and Canadian Nuclear Laboratories (CNL) - Associations including representation on behalf of the Institute of Asset Management and; - Contractors including Mission Support Alliance, Mott McDonald, and Longenecker and Associates The objective of this meeting was to share information about respective 'best practices' and to begin to develop common approaches to the prioritization and management of aging infrastructure investment across the organizations. The exchange focused on identifying common critical issues which were discussed through a series of presentations and small group discussions. The outcome from the meeting was an improved understanding by all participants of the latest approaches being applied to Infrastructure Asset Management and the formation of four International Working Groups which now meet on a regular (4-6 week) basis to share lessons learned and to develop international best practice in their area of interest. This paper details; - the issues and challenges that were identified during the meeting - how these were assimilated and distilled into discrete areas to enable formation of specific Working Groups - progress made by the Working Groups to date. (authors)

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An Industrial Perspective of Research Within the DISTINCTIVE Program - 18045

UK Engineering and Physical Sciences Research Council (EPSRC) and three industrial partners, the Nuclear Decommissioning Authority (NDA), the National Nuclear Laboratory (NNL) and Sellafield Ltd (SL) are supporting the DISTINCTIVE (Decommissioning, Immobilisation and Storage Solutions for Nuclear Waste Inventories) consortium of eleven universities to carry out research in four theme areas of importance to the UK nuclear industry: Advanced Gas-cooled Reactor (AGR), Magnox and exotic spent fuels; PuO{sub 2} and fuel residues; legacy ponds and silo wastes; and structural integrity. This paper describes the main industry challenges in each of these theme areas and some of industry led activities to address these challenges, and provides examples of where the DISTINCTIVE research output is assisting the nuclear industry in meeting these challenges. (authors)

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Results of Robotic Evaluation of Uranium-235 in Gaseous Diffusion Piping Holdup Deposits - 18303

Measurement of U-235 in pipes within old uranium enrichment facilities is time-consuming and very costly. Radiometric assay from outside the pipes suffers from manual deployment challenges, attenuation of detection through pipe walls, long counting times, approximate modeling, and shortfalls associated with transcription and human interpretation. The D and D process of cutting into these pipes creates a unique possibility of robotic in-pipe assay to address these problems. This paper presents the results of testing a first-of-kind radiometric non-destructive assay (NDA) robot for high-cadence, accurate, certain, paperless assay of U-235 in holdup deposits within process piping. The robot's enabling capability is an innovative radiometric collimation method that views only a one-foot moving annulus of pipe wall. This exploits the internal axisymmetry of pipes to provide a direct measurement of industry-standard grams per foot U-235. The initial proof-of-application robot was successfully hot tested by operators at the Gaseous Diffusion Enrichment Facility in Piketon, Ohio, in late 2017. This testing achieved all goals of traversing pipe, measuring U-235, deployment by facility personnel, and displaying analyzed radiation, visual, and geometric information. The success was a Kitty Hawk moment. The system demonstrated robotic in-pipe measurement of holdup deposit to a resolution, accuracy, and speed unachievable by alternate methods. (authors)

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Dounreay (UK) Shaft and Silo Decommissioning - Remote Handling in an Extreme and Uncertain Environment - 18420

DSRL is a wholly-owned subsidiary of the Cavendish Dounreay Partnership Ltd, a consortium of Cavendish Nuclear, CH2M and AECOM. It is funded by the Nuclear Decommissioning Authority (NDA) to deliver the site closure programme. Today, Dounreay is a site of construction, demolition and waste management, all of it designed to return the site to an interim end state. Dounreay is recognised as the most complex nuclear site closure project in Europe. The experimental nature of many of the sites redundant facilities means the clean-up and demolition requires innovation as well as great care. It is driving innovation in the approach to remote handling and robotics in the highly complex, hazardous and uncertain environment, all within tight financial constraints by UK Government. Veolia Nuclear Solutions (VNS) is instrumental in delivery of the overall solutions for the shaft and silo decommissioning project working with other members of industry and directly for DSRL to deliver the overall concept design for waste treatment as well as specialised equipment to recover highly hazardous and uncertain materials in this unique project. (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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Waste is our Product. Developing, Implementing and Optimising Waste Management at Dounreay - 19039

The UK's Fast Breeder Reactor Research programme was centred at Dounreay, in the very north of Scotland, from 1955. Since 1994, the site has been focused on decommissioning, and represents one of the most complex, technically challenging and hazardous nuclear clean-up projects in Europe. Since 2012, Dounreay Site Restoration Ltd (DSRL) has been contracted by the NDA as the Site License Company to deliver the defined scope of work, under a Target Cost contract, to decommission the site to achieve the Interim End State by 2030-2033, whilst managing the transition of its people. All parties, including DSRL's Parent Body Organisation Cavendish Dounreay Partnership Ltd (a consortium of Cavendish Nuclear, AECOM, and Jacobs), recognise that there are significant technical and regulatory challenges to achieve this, as well as safely managing the transition for our workforce on what is effectively a 'closure' contract. The product of decommissioning is waste; over the course of the programme, a full range of higher activity and lower level radioactive wastes will be generated, and must be safely managed. This paper will address: - The Policy issues relating to radioactive waste management at Dounreay, including particular issues relating to implementation of Scottish policy, including how Waste Management is Optimised. - An overview of the decommissioning programme and the delivery of an Interim End State; - The type, range and nature of radioactive wastes requiring safe management at Dounreay; - Higher Activity Wastes (HAW): - Setting higher activity waste strategy; defining products and interim storage requirements; - Technical, regulatory and stakeholder issues for HAW strategy; - Lower Activity Wastes: - Setting Low Level Waste (LLW) strategy; defining a disposal product and development and status for Dounreay's LLW Disposal Vaults; - Implementing LLW strategy; - Technical, regulatory and stakeholder issues for LLW strategy; - Optimising Waste Management -Optimising waste from generation (from decommissioning workfaces) through to disposal -why, and how; - The Waste Informed Decommissioning model as a methodology and approach; - Impact and importance of Waste Management on a target cost contract; - Establishment of a Waste Optimisation Programme to drive ownership, delivery and culture change; - Management responsibilities and informing organisational design; - Sharing and learning from Best Practice; - The Challenge - how to ensure workforce and teams are engaged in delivering optimisation requirements; - Conclusions. (authors)

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International Government Collaboration in ISD (In Situ Decommissioning/In Situ Disposal) - 19261

In situ decommissioning (ISD) is considered by IAEA as the permanent entombment of a legacy facility in 'a structurally long lived material' (e.g. concrete) and is considered a solution only under 'exceptional circumstances' (e.g. following a severe accident). However, this definition of ISD as 'only' entombment is not universally accepted; the approach has been implemented as a decommissioning approach by the US Dept of Energy in the past decade at the Savannah River Site (P and R reactors)2,3, the Hanford site (U Canyon) and at the Idaho site (CP601, CP640 and CP633). The application of ISD outside of the United States has been much less common for large facilities although its use for underground substructures (e.g. discarded pipelines) is commonplace. Proponents of ISD consider it beneficial since it eliminates the need to remove, package and transport contaminated equipment from a nuclear legacy site to a disposal facility and it maximizes the use of an existing nuclear site footprint by consolidating equipment in one place. ISD is considered to offer major safety benefits to both workers and the public, as well as major cost and schedule benefits to Government. Opponents of the approach cite the fact that, following ISD, the decommissioned facility has effectively become a long-term waste disposal site and that regulations pertaining to long term waste disposal have been circumvented. Given the increasing pressure on environmental cleanup budgets and schedules around the world, countries such as the United Kingdom, Canada and Japan are considering ISD in its various forms as a potential path forward for decommissioning certain facilities in lieu of the more traditional approaches of either deferred decommissioning or immediate decontamination/demolition. To address this emerging area of decommissioning, a Governmental Technical Information Exchange meeting was held in December 2017 at the DOE Savannah River Site in Aiken, SC, to bring together responsible parties from the US Dept of Energy (DOE), Atomic Energy of Canada Ltd (AECL), the UK Nuclear Decommissioning Authority (NDA) and the Japanese Atomic Energy Agency (JAEA) and those countries' respective regulatory agencies to share information about respective 'best practices' and challenges with ISD. Representatives from organizations such as IAEA and US Nuclear Regulatory Commission (US NRC) also participated to discuss their organizations' perspectives and position on ISD. Following the meeting, a series of Working Groups were established which have continued the dialogue in three key areas 5; - ISD-Defined: Identify and share case-specific ISD solutions which allows for the full spectrum of needs and which demonstrate that 'entombment' is not the only definition of 'ISD'. - Regulatory - Share and discuss regulatory concerns and challenges with ISD; - Benchmarking - Share information to support informed and transparent decision-making in ISD. This paper discusses the plans for ISD in some of the countries involved in the December meeting and provides an update on the topics being discussed, and progress being made, by the Working Groups that were formed at the meeting. (authors)

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Panel Session 19: Developments in the Clean-up Mission of Sellafield

This panel focused on the progress towards closure of the legacy ponds and silos on the Sellafield Site. The discussion included progressive learning, technical challenges, safety, and regulatory flexibility required to achieve cleanup. The panel included NDA, regulators and Sellafield Ltd. Presentations proposed include: 1 - Developments in the Cleanup of Sellafield: An Owners Perspective (Adrian Simper, Nuclear Decommissioning Authority UK (United Kingdom)); 2 - Sellafield Ltd (Lee Peck, Sellafield Ltd. (United Kingdom)); 3 - Developments in the Clean-up Mission at Sellafield (Ian Dallas, Office for Nuclear Regulation (United Kingdom)); 4 - Developments in the Clean-up Mission of Sellafield, UK (Steven Thomson, National Nuclear Laboratory (United Kingdom))

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A Robot for Nondestructive Assay of Holdup Deposits in Gaseous Diffusion Piping - 19504

Miles of contaminated pipe must be characterized as part of the decommissioning effort at deactivated gaseous diffusion enrichment facilities. The current method requires cutting away asbestos- lined thermal enclosures and performing repeated, elevated operations to manually perform nondestructive assay (NDA) on pipe from the outside. The RadPiper robot, part of the Pipe Crawling Activity Measurement System (PCAMS) developed by Carnegie Mellon University and commissioned for use at the DOE Portsmouth Gaseous Diffusion Enrichment Facility, automatically measures U-235 in pipes from the inside. This improves certainty, increases safety, and greatly reduces measurement time. The heart of the RadPiper robot is a sodium iodide scintillation detector in an innovative disc-collimated assembly. By measuring from inside pipes, the robot significantly increases its count rate relative to external through-pipe measurements. The robot also provides imagery, models interior pipe geometry, and precisely measures distance in order to localize radiation measurements. Data collected by this system provides insight into pipe interiors that is simply not possible from exterior measurements, all while keeping operators safer. This paper describes the technical details of the PCAMS RadPiper robot. Key features for this robot include precision distance measurement, in-pipe obstacle detection, ability to transform for two pipe sizes, and robustness in autonomous operation. Test results demonstrating the robot's functionality are presented, including deployment tolerance tests, safeguarding tests, and localization tests. Integrated robot tests are also shown. (authors)

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Panel Session 132: Risk-Informed Approach for Decision Making in WM, D and D and SNF Management: Reasonable Assurance for Safety

Mr. Larry Camper organized a panel of experts to discuss approaches to better make risk-informed decisions in waste management, decommissioning, and the management of Spent Nuclear Fuel (SNF). The audience heard the perspectives from four panelists that addressed issues ranging from the technical basis used to make risk-informed decisions to for developing cleanup criteria and promulgating regulations and safety standards both domestically and abroad. A summary of each of the presentations given by the panelists is provided herein. This WMS BOD featured panel focused on the Risk-Informed Approach for Decision Making in WM, D and D and SNF Management and the Reasonable Assurance for Safety. The panelists addressed and discussed with the audience different approaches used for decision-making, summarizing ongoing probabilistic vs. deterministic approaches, including IAEA graded approach, and discussed policies/approaches to achieve reasonable assurance for safety rather than using absolute assurance. Panelists with presentations: Risk-Informed Decision Making - More than a Motto? (Paul Black); NRC Staff Perspective on Risk-Informed Approach and Reasonable Safety Assurance in D and D and LLW (Rateb (Boby) Abu Eid); Risk-Informed Decision-Making and Illustrative National Academies Studies (Charles Ferguson); IAEA's Revised Safety Guidance on Remediation (Michelle Roberts); NDA Radioactive Waste Strategy - A Risk Informed Approach (James McKinney)

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A Systematic Evidence Based Performance Approach to Regulation of Nuclear Sites in England and Wales - 20058

The Environment Agency for England has developed a systematic evidence-based approach to pursue our strategic environmental objectives for the regulation of nuclear sites. We use an annual evidence review process to ensure effective and efficient targeting of limited resources to achieve those objectives. Over the last 8 years, we have been developing and refining this approach to ensure risk-based and value driven regulation. The approach comprises nuclear site and nuclear sector review processes known as Site Environment Review (SER) and Nuclear Environment Review (NER). This approach complements our regulation of nuclear site permit holders under the Environmental Permitting Regulations (EPR). We deliver our regulation of nuclear sites in England and Wales alongside the Office for Nuclear Regulation. The SER process involves the lead regulator for each nuclear site assessing the permit holder's environmental performance across 14 themes, set within the context of the site's main activities and associated waste disposals. Our themes include environmental leadership, resources and climate change, radioactive waste management, facility management and decommissioning, groundwater, and environmental radiological protection. We use evidence from site inspections and working within our subject matter groups to grade current and predicted future environmental performance. We are particularly interested in sustainability and the application of Best Available Techniques (BAT) to prevent the creation, and minimise the disposal, of radioactive wastes. We use risk analysis (strengths, weaknesses, threats and opportunities) to examine performance against our strategic environmental objectives, which are set out, in our 5-year Nuclear Delivery Plan (NDP). The output supports the targeting of our resources at each nuclear site. We consult the relevant permit holders on the SER priorities and use their feedback to refine our plans. We expect all permit holders to take account of our priorities when considering their own programmes of work, objectives and plans. The NER process brings together what we learn and achieve through regulation across the sector. It provides input to planning priorities, supported by qualitative and semi-quantitative evidence. It covers the 28 nuclear sites in England and Wales and spans the same 14 environmental themes. During the process we collate, compile and summarise evidence from the SERs and other sources such as inspection reports and evidence from our other nuclear work programmes. The output is the NER annual report. This provides a snapshot of the status of the nuclear sector and gives insights to enable us to regulate more efficiently and effectively. It also takes account of cross-cutting issues and risks such as changes in international standards, domestic policy, regulatory framework, domestic standards and guidance, learning from experience such as incidents, events and good practice, and innovation, research and development. It provides graphics that illustrate the grading of environmental performance for the nuclear sector across the fourteen environmental themes. This analysis allows benchmarking of nuclear site's environmental performance and the visualisation provides a convenient comparison of performance across themes, sites, and over time. We use this intelligence to inform our investment in training and development of our staff, and our cross-cutting engagement on strategic issues with government, the Nuclear Decommissioning Authority (NDA) and other corporate organisations. Adopting this approach can provide benefits with organisational reputation, stakeholder participation and ensuring value from the public investment. This paper describes the history of the SER/NER process, a selection of outputs from the process and ideas for improvement. The paper will be of interest to other regulators and organisations across the world that are interested in supporting continuous improvement. (authors)

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Inspection of Dry Storage Casks Using PGAA and NAA Techniques

In this effort, an assessment of a chloride detection method is performed for inspecting the surfaces of dry cask storage system (DCSS) canisters, with focus on the implementation of a non-destructive nuclear analysis and methodology. Some DCSS canisters (especially those located in coastal environments) will be exposed to marine environments, which can cause atmospheric stress corrosion cracking (SCC). Chloride deposits on canister surfaces provide the corrosive environment necessary for atmospheric SCC with the residual stresses and materials properties conditions. The most susceptible regions on the canister surface are the weld areas, or where cold work has been performed, and may provide the necessary driving force for crack growth. The heat-affected zones (HAZs) near welds are also potentially susceptible to atmospheric SCC due to sensitization of the material caused by chromium depletion during the welding process. Information collected from the field and from laboratory studies has not been able to rule out the possibility of atmospheric chloride induced stress corrosion cracking (CISCC), although no occurrences of atmospheric SCC in DCSS canisters have been detected to-date. A number of researchers have demonstrated that localized corrosion can take place under such situations on materials commonly used for interim storage containers, including 304SS (Cook et al. 2010; Shirai et al. 2011) and 316SS (Tani et al. 2009). In this summary, the preliminary results of a neutron activation analysis (NAA) and prompt gamma activation analysis (PGAA) are performed using MCNP6, a highly sophisticated, multi-particle Monte Carlo simulation code (with the employment of the high performance computing system at the Idaho National Laboratory), and confirm the feasibility of using PGAA and NAA as an environmental inspection methodology for detection and monitoring of small quantities of chlorine on canister surfaces. The specific signature of gamma rays due reactions of sea salt constituents are documented and summarized in this paper. The environmental constituent for passive oxide film breaching is chlorine, which can cause pitting initiation and incubation time that may lead to cracking in stainless steel. Therefore, an assessment of chloride presence at a canister surface is essential before moving to other nondestructive analysis (NDA) methods for detection of pitting and cracking. Two nonlinear acoustic techniques will also be used in our integrated research project (IRP) research study that proves to be useful in the detection of SCC: nonlinear resonant ultrasound spectroscopy (NRUS), and time revisited elastic nonlinear diagnostic (TREND). These two techniques are complementary to marine atmospheric detection techniques. In this presentation only PGAA and NAA are described in detail. (authors)

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Establishing no credible risk of inadvertent criticality for the K-25 demolition project - 14310

Demolition of the K-25 Gaseous Diffusion Plant required establishing a non-credible risk of inadvertent criticality because a Criticality Accident Alarm System (CAAS) could not be reliably maintained operable as the building was being torn down. Preparation for, and demolition of, the facility was a multi-year long effort with significant changes in approach. The most significant change was to demolish the facility with as much of the process gas equipment and piping left in the facility as possible, rather than removing all process gas equipment and piping from the facility prior to demolishing the building structure only. The contractor had to adapt their approach to accommodate these changes. The normal approach to demolition was to remove all process gas equipment and piping prior to demolition, using Nuclear Criticality Safety (NCS) controls based on the double contingency principle, while CAAS coverage was intact. Then, the building structure was demolished with no requirement for a CAAS. This was the method used to demolish the K-33 Building, for example. In the case of K-25 demolition, all equipment and piping that met the Environmental Management Waste Management Facility (EMWMF) disposal cell Waste Acceptance Criteria (WAC) was left in the building and removed as part of the building demolition process. This resulted in significant quantities of fissionable material remaining in the building and being handled during demolition. The NCS Organization worked closely with several groups during preparation activities. A Data Management organization was established to specifically identify every piece of process gas equipment and piping in the facility so that it could be accounted for and characterized. Deactivation and Decommissioning (D and D) personnel conducted internal visual inspections, by remote camera, of all process gas equipment and piping larger than 3' diameter, to reveal any large deposits that would require removal. Non-Destructive Assay (NDA) of the vast majority of equipment and piping was required to quantify the amount of fissionable material remaining. Finally, all process gas equipment and piping larger than 3'' diameter was internally filled with foam, which was credited by NCS with immobilizing the remaining fissionable material such that large migration and accumulation could not occur during demolition activities. NCS personnel worked closely with all of these groups in order to acquire the data and information needed to establish a non-credible risk of inadvertent criticality during building demolition. Good communication and a close working relationship between NCS, the various D and D/characterization personnel, and the Department of Energy (DOE) ensured the success of the modified approach to building demolition. The same successful approach is currently underway in the K-27 Building as well. (authors)

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗