bluuebunny/crossref_metadata_2025 huggingface dataset:
FtsHi1/ARC1 is an essential gene in Arabidopsis that links chloroplast biogenesis and division
Authors: Kadirjan‐Kalbach Deena K. , Yoder David W. , Ruckle Michael E. , Larkin Robert M. , Osteryoung Katherine W.
Published: August 2012

The Arabidopsis arc1 (accumulation and replication of chloroplasts 1) mutant has pale seedlings and smaller, more numerous chloroplasts than the wild type. Previous work has suggested that arc1 affects the timing of chloroplast division but does not function directly in the division process. We isolated ARC1 by map‐based cloning and discovered it encodes FtsHi1 (At4g23940), one of several FtsHi proteins in Arabidopsis. These poorly studied proteins resemble FtsH metalloproteases important for organelle biogenesis and protein quality control but are presumed to be proteolytically inactive. FtsHi1 bears a predicted chloroplast transit peptide and localizes to the chloroplast envelope membrane. Phenotypic studies showed that arc1 (hereafter ftsHi1‐1), which bears a missense mutation, is a weak allele of FtsHi1 that disrupts thylakoid development and reduces de‐etiolation efficiency in seedlings, suggesting that FtsHi1 is important for chloroplast biogenesis. Consistent with this finding, transgenic plants suppressed for accumulation of an FtsHi1 fusion protein were often variegated. A strong T‐DNA insertion allele, ftsHi1‐2, caused embryo‐lethality, indicating that FtsHi1 is an essential gene product. A wild‐type FtsHi1 transgene rescued both the chloroplast division and pale phenotypes of ftsHi1‐1 and the embryo‐lethal phenotype of ftsHi1‐2. FtsHi1 overexpression produced a subtle increase in chloroplast size and decrease in chloroplast number in wild‐type plants while suppression led to increased numbers of small chloroplasts, providing new evidence that FtsHi1 negatively influences chloroplast division. Taken together, our analyses reveal that FtsHi1 functions in an essential, envelope‐associated process that may couple plastid development with division.
Evolutionary force of AT‐rich repeats to trap genomic and episomal DNAs into the rice genome: lessons from endogenous pararetrovirus
Authors: Liu Ruifang , Koyanagi Kanako O. , Chen Sunlu , Kishima Yuji
Published: August 2012

In plant genomes, the incorporation of DNA segments is not a common method of artificial gene transfer. Nevertheless, various segments of pararetroviruses have been found in plant genomes in recent decades. The rice genome contains a number of segments of endogenous rice tungro bacilliform virus‐like sequences (ERTBVs), many of which are present between AT dinucleotide repeats (ATrs). Comparison of genomic sequences between two closely related rice subspecies, japonica and indica, allowed us to verify the preferential insertion of ERTBVs into ATrs. In addition to ERTBVs, the comparative analyses showed that ATrs occasionally incorporate repeat sequences including transposable elements, and a wide range of other sequences. Besides the known genomic sequences, the insertion sequences also represented DNAs of unclear origins together with ERTBVs, suggesting that ATrs have integrated episomal DNAs that would have been suspended in the nucleus. Such insertion DNAs might be trapped by ATrs in the genome in a host‐dependent manner. Conversely, other simple mono‐ and dinucleotide sequence repeats (SSR) were less frequently involved in insertion events relative to ATrs. Therefore, ATrs could be regarded as hot spots of double‐strand breaks that induce non‐homologous end joining. The insertions within ATrs occasionally generated new gene‐related sequences or involved structural modifications of existing genes. Likewise, in a comparison between Arabidopsis thaliana and Arabidopsis lyrata, the insertions preferred ATrs to other SSRs. Therefore ATrs in plant genomes could be considered as genomic dumping sites that have trapped various DNA molecules and may have exerted a powerful evolutionary force.
Neurohypophyseal response to fluid resuscitation with hypertonic saline during septic shock in rats
Authors: Santiago Michael Brian , Vieira Alexandre Antonio , Elias Lucila L. K. , Rodrigues José Antunes , Giusti‐Paiva Alexandre
Published: August 2012

New findings

What is the central question of this study?

Small‐volume resuscitation with hypertonic saline (HS) has been proposed to restore physiological haemodynamics during haemorrhagic and endotoxic shock. Hypertonic solutions rapidly increase intravascular volume by generating an osmotic gradient that pulls water from the intracellular and interstitial space into the intravascular compartment. Infusion of HS increases plasma sodium levels and osmolality, which may stimulate hormone release from the neurohypophysis. In the present study, we sought to investigate the effects of HS administration during septic shock caused by caecal ligation and perforation.

What is the main finding and its importance?

The present study demonstrated that HS infusion into rats subjected to caecal ligation and perforation induced neurohypophyseal hormone secretion, as well as a transient increase in blood pressure that was mediated by the V1 receptor.

Septic shock is a serious condition with a consequent drop in blood pressure and inadequate tissue perfusion. Small‐volume resuscitation with hypertonic saline (HS) has been proposed to restore physiological haemodynamics during haemorrhagic and endotoxic shock. In the present study, we sought to determine the effects produced by an HS infusion in rats subjected to caecal ligation and perforation (CLP). Male Wistar rats were randomly grouped and submitted to either CLP or sham surgery. Either HS (7.5% NaCl, 4 ml kg−1 i.v.) or isotonic saline (IS; 0.9% NaCl, 4 ml kg−1 i.v.) was administered 6 h after CLP. Recordings of mean arterial pressure and heart rate were made during this protocol. Moreover, measurements of electrolyte, vasopressin and oxytocin secretion were analysed after either the HS or the IS treatment. Six hours after CLP, we observed a characteristic decrease in mean arterial pressure that occurs after CLP. The HS infusion in these rats produced a transient elevation of the plasma sodium concentration and osmolality and increased plasma vasopressin and oxytocin levels. Moreover, the HS infusion could restore the mean arterial pressure after CLP, which was completely blunted by the previous injection of the vasopressin but not the oxytocin antagonist. The present study demonstrated that rats subjected to CLP and an infusion of hypertonic saline respond with secretion of neurohypophyseal hormones and a transient increase in blood pressure mediated by the V1 receptor.
Elevated local skin temperature impairs cutaneous vasoconstrictor responses to a simulated haemorrhagic challenge while heat stressed
Authors: Pearson J. , Lucas R. A. I. , Crandall C. G.
Published: August 2012

New findings

What is the central question of this study?

Individuals exposed to combined heat stress and simulated haemorrhage show small but insufficient reductions in cutaneous vascular conductance at presyncope in non‐heated skin. In the vast majority of skin directly exposed to increases in temperature during whole‐body heat stress, the cutaneous vascular response during simulated haemorrhage to presyncope is unclear.

What is the main finding and its importance?

During whole‐body heat stress followed by simulated haemorrhage to presyncope, cutaneous vasoconstriction is absent/negligible in directly heated skin. These results have important implications for blood pressure control in individuals who are often heat stressed and at a higher risk for experiencing haemorrhage, such as soldiers.

During a simulated haemorrhagic challenge, syncopal symptoms develop sooner when individuals are hyperthermic relative to normothermic. This is due, in part, to a large displacement of blood to the cutaneous circulation during hyperthermia, coupled with inadequate cutaneous vasoconstriction during the hypotensive challenge. The influence of local skin temperature on these cutaneous vasoconstrictor responses is unclear. This project tested the hypothesis that local skin temperature modulates cutaneous vasoconstriction during simulated haemorrhage in hyperthermic humans. Eight healthy participants (four men and four women; 32 ± 7 years old; 75.2 ± 10.8 kg) underwent lower‐body negative pressure to presyncope while heat stressed via a water‐perfused suit sufficiently to increase core temperature by 1.2 ± 0.2°C. At forearm skin sites distal to the water‐perfused suit, local skin temperature was either 35.2 ± 0.6 (mild heating) or 38.2 ± 0.2°C (moderate heating) throughout heat stress and lower‐body negative pressure, and remained at these temperatures until presyncope. The reduction in cutaneous vascular conductance during the final 90 s of lower‐body negative pressure, relative to heat‐stress baseline, was greatest at the mildly heated site (−10 ± 15% reduction) relative to the moderately heated site (−2 ± 12%; P= 0.05 for the magnitude of the reduction in cutaneous vascular conductance between sites), because vasoconstriction at the moderately heated site was either absent or negligible. In hyperthermic individuals, the extent of cutaneous vasoconstriction during a simulated haemorrhage can be modulated by local skin temperature. In situations where skin temperature is at least 38°C, as is the case in soldiers operating in warm climatic conditions, a haemorrhagic insult is unlikely to be accompanied by cutaneous vasoconstriction.
Pollution Prevention Benefits of Dissolvable Protective Clothing
Authors: Cournoyer Michael E. , Wannigman David L. , Dodge Robert L.
Published: August 2012

Programmatic operations at the Los Alamos National Laboratory Plutonium Facility (TA-55) involve working with various amounts of plutonium and other highly toxic, alpha-emitting materials. The spread of radiological contamination on surfaces, airborne contamination, and excursions of contaminants into the operator’s breathing zone are controlled through the radiological protection program. A key element of this program is the proper selection of protective clothing. Re-useable, launderable protective clothing has been the standard for several decades. Over the years, radioactive waste disposal costs have increased and disposal options have become more limited. This has prompted the development of single-use, dissolvable protective clothing. Single-use, dissolvable protective clothing is under evaluation as a replacement for launderable woven textile garments at TA-55. We examined re-useable, launderable and single-use, dissolvable protective clothing, addressed management issues (residual contamination, cost, environmental footprint, quality assurance), and waste minimization benefits. Replacement of launderable garments with single-use, dissolvable protective clothing improves the safety configuration of TA-55 by reducing LLW waste generation.
Preliminary Demonstration of GeoMelt Treatment of Hanford’s K-Basin Sludge
Authors: Witwer Keith
Published: August 2012

The U.S. Department of Energy (DOE) and CH2M Hill Plateau Remediation Company (CHPRC) are seeking a waste treatment solution for sludge stored in the K-Basin spent fuel pond at the Hanford Nuclear Site, in Washington State, USA. This sludge is a Remote Handled Transuranic (RHTRU) waste destined for final disposal at the Waste Isolation Pilot Pant (WIPP) in New Mexico. Removal of the sludge from the K-Basin and transport for interim storage at the Hanford Site is referred to as Phase 1 in this process. Phase 2 is defined as the treatment and packaging of the sludge such that it can be transported and disposed at the WIPP. This paper discusses work in support of Phase 2. ISI’s GeoMelt ICV process is ideally suited to treating a heterogeneous sludge that is rich in uranium metal and which contains a mixture of other fuel derived products, earthen materials, and miscellaneous items (operational debris, resin, etc). GeoMelt can quickly and efficiently treat small drum load batches and will fully destroy organics, oxidize reactive metals, and permanently immobilize radioactive constituents within a high-integrity vitrified product that will meet or exceed all WIPP acceptance criteria. The GeoMelt Technology has an extensive experience base, having treated more waste by vitrification than any other company in the world (25,500 metric tons). The equipment tested for this Project phase constituted the front end, or Sludge Pretreatment and Transport steps, of the proposed GeoMelt process. These components first focused on an engineering scale (22-liter), followed by testing with a full-scale (130-liter), horizontal rotary plow dryer/mixer. The dryer removes water from the sludge, via external heating and under reduced pressure, and mixes it with glass forming minerals (GFM) prior to treatment in the GeoMelt ICV system. Testing was first performed in July and September 2010 using a 22-liter drying system, which demonstrated a baseline drying technique and allowed an assessment of the resulting physical properties before, during, and after drying/mixing. Full-scale testing using a 130-liter dryer and condensate system was then performed in October 2010. An Operational Acceptance Test (OAT) of the equipment, followed by four “Dryer Holdup” tests and three “GFM Cleanout” tests were performed. Each of the Project Test Objectives was successfully met. Both the 22-liter engineering-scale and the 130-liter full-scale steam jacketed, horizontal plow, dryer are shown to dry and mix 5-vol% solids K-Basin sludge and GFM without difficulty. These test results, combined with previous treatability testing in 2004 wherein successful GeoMelt vitrification of a K-Basin sludge simulant was demonstrated, confirm the efficacy of the overall treatment process towards providing an immediate solution to the final disposition of K Basin Sludge.
Feedback From Westinghouse Experience on Segmentation of Reactor Vessel Internals
Authors: Kreitman Paul J. , Boucau Joseph , Segerud Per , Fallstro¨m Stefan
Published: August 2012

With more than 25 years of experience in the development of reactor vessel internals segmentation and packaging technology, Westinghouse has accumulated significant know-how in the reactor dismantling market. Building on tooling concepts and cutting methodologies developed decades ago for the successful removal of nuclear fuel from the damaged Three Mile Island Unit 2 reactor (TMI-2), Westinghouse has continuously improved its approach to internals segmentation and packaging by incorporating lessons learned and best practices into each successive project. Westinghouse has developed several concepts to dismantle reactor internals based on safe and reliable techniques, including plasma arc cutting (PAC), abrasive waterjet cutting (AWJC), metal disintegration machining (MDM), or mechanical cutting. Westinghouse has applied its technology to all types of reactors covering Pressurized Water Reactors (PWR’s), Boiling Water Reactors (BWR’s), Gas Cooled Reactors (GCR’s) and sodium reactors. The primary challenges of a segmentation and packaging project are to separate the highly activated materials from the less-activated materials and package them into appropriate containers for disposal. Since space is almost always a limiting factor it is therefore important to plan and optimize the available room in the segmentation areas. The choice of the optimum cutting technology is important for a successful project implementation and depends on some specific constraints like disposal costs, project schedule, available areas or safety. Detailed 3-D modeling is the basis for tooling design and provides invaluable support in determining the optimum strategy for component cutting and disposal in waste containers, taking account of the radiological and packaging constraints. Westinghouse has also developed a variety of special handling tools, support fixtures, service bridges, water filtration systems, video-monitoring systems and customized rigging, all of which are required for a successful reactor vessel internals segmentation and packaging project. The purpose of this paper is to provide an overview of the Westinghouse reactor internals segmentation experience by illustrating projects related to various types of reactors and providing feedback from project execution.
How an Integrated Change Programme Has Accelerated the Reduction in High Hazard Nuclear Facilities at Sellafield
Authors: Mackintosh Angela
Published: August 2012

For over five decades the Sellafield Site has been central to the UK’s nuclear programme. Sellafield Ltd is managed by NMP (Nuclear Management Partners), a consortium of URS, AMEC and AREVA and is focussed on the decommissioning of historical facilities. When the activity of Decommissioning commenced in the late 1980’s the site focus at that time was on commercial reprocessing and waste management. Now through the implementation of an integrated company change programme, emphasis has shifted towards accelerated risk and hazard reduction of degraded legacy plants with nuclear inventory whilst ensuring value for money for the customer, the Nuclear Decommissioning Authority (NDA). This paper will describe the management approach that is being taken and the planning tools that are being applied by the Site owners in delivering an integrated change programme across the Decommissioning Directorate. The paper will explain how the management approach to change uses Peer Assist, Rapid Improvement Events, Organisational Review Self Evaluation, Value Stream Analysis and Accelerated Improvement Events as improvement tools. Use of these has enabled downsizing of the organisation, driven out hundreds of man day efficiencies within the maintenance and asset management areas, improved the management of spares reducing annual costs by £1000’s, improved Commercial practices by fast tracking the preparation of invitations to tender for critical contracts, rolled back radiological control areas and enabled quicker access to the workface at a reduced cost. This paper will explain in detail how the Decommissioning Directorate Programme Office has implemented planning tools such as governance, identification of opportunities, benefit evaluation and prioritisation and sanction of the optimum improvements and how through the use of a balanced scorecard, delivery of the improvements has been measured ensuring that the targets are met. Finally, the paper will discuss how the Performance Improvement Action Plan has proved to be critical for presenting the change plan and its delivery to key stakeholders, Government owners and powerful regulators. Overall, this paper provides an insight into how a massive change programme is being managed within one of the world’s highest regulated industries.
Measurement Methodology for Fulfilling of Waste Acceptance Criteria for Low and Intermediate Level Radioactive Waste in Storages
Authors: Sokcic-Kostic M. , Langer F. , Schultheis R.
Published: August 2012

Low and intermediate level radioactive waste must be sorted and treated before it can be sent to radioactive waste storage. The waste must fulfil an extensive amount of acceptance criteria (WAC) to guarantee a safe storage period. NUKEM Technologies has a broad experience with the building and management of radioactive waste treatment facilities and has developed methods and equipment to produce the waste packages and to gather all the required information.
Waste Loading Enhancements for Hanford Low-Activity Waste Glasses
Authors: Kruger Albert A.
Published: August 2012

About 50 million gallons of mixed waste is currently stored in underground tanks at The United States Department of Energy’s (DOE) Hanford site in Washington state. The Hanford Tank Waste Treatment and Immobilization Plant (WTP) will provide the Office of River Protection (ORP) with a means of treating this waste by vitrification for subsequent disposal. The tank waste will be separated into low- and high-activity waste fractions, which will then be vitrified respectively into Immobilized Low Activity Waste (ILAW) and Immobilized High Level Waste (IHLW) products. The ILAW product is destined for disposal in an engineered facility at Hanford site while the IHLW product will be disposed in a national geological repository. Both waste forms must meet a variety of requirements to ensure the protection of the environment before they can be accepted for disposal.
Foam: Novel Delivery Technology for Remediation of Vadose Zone Environments
Authors: Jansik Danielle , Wellman Dawn M. , Mattigod Shas V. , Zhong Lirong , Wu Yuxin , Foote Martin , Zhang Fred , Hubbard Susan
Published: August 2012

Deep vadose zone environments can be a primary source and pathway for contaminant migration to groundwater. These environments present unique characterization and remediation challenges that necessitate scrutiny and research. The thickness, depth, and intricacies of the deep vadose zone, combined with a lack of understanding of the key subsurface processes (e.g., biogeochemical and hydrologic) affecting contaminant migration, make it difficult to create validated conceptual and predictive models of subsurface flow dynamics and contaminant behavior across multiple scales. These factors also make it difficult to design and deploy sustainable remedial approaches and monitor long-term contaminant behavior after remedial actions. Functionally, methods for addressing contamination must remove and/or reduce transport of contaminants. This problem is particularly challenging in the arid western United States where the vadose zone is hundreds of feet thick, rendering transitional excavation methods exceedingly costly and ineffective. Delivery of remedial amendments is one of the most challenging and critical aspects for all remedy-based approaches. The conventional approach for delivery is through heterogeneous deep vadose zone environments present hydrologic and geochemical challenges that limit the effectiveness. Because the flow of solution infiltration is dominantly controlled by gravity and suction, injected liquid preferentially percolates through highly permeable pathways, by-passing low-permeability zones that frequently contain the majority of contamination. Moreover, the wetting front can readily mobilize and enhance contaminant transport to the underlying aquifer prior to stabilization. Development of innovative in-situ technologies may be the only means to meet remedial action objectives and long-term stewardship goals. Surfactants can be used to lower the liquid surface tension and create stabile foams, which readily penetrate low permeability zones. Although surfactant foams have been used for subsurface mobilization efforts in the oil and gas industry, thus far the concept of using foams as a delivery mechanism for transporting remedial amendments into deep vadose zone environments to stabilize metal and long-lived radionuclide contaminants has not been explored. Foam flow can be directed by pressure gradients, rather than being dominated by gravity; and foam delivery mechanisms limit the volume of water (< 5% vol.) required for remedy delivery and emplacement, thus mitigating contaminant mobilization. We will present the results of a numerical modeling and integrated laboratory-/intermediate-scale investigation to simulate, develop, demonstrate, and monitor (i.e., advanced geophysical techniques and advanced predictive biomarkers) foam-based delivery of remedial amendments to remediate metals and radionuclides in vadose zone environments.
Cementitious Materials for Radioactive Waste Management Within IAEA Coordinated Research Project
Authors: Drace Zoran , Ojovan Michael I.
Published: August 2012

The IAEA Coordinated Research Project (CRP) on cementitious materials for radioactive waste management was launched in 2007 [1, 2]. The objective of CRP was to investigate the behaviour and performance of cementitious materials used in radioactive waste management system with various purposes and included waste packages, wasteforms and backfills as well as investigation of interactions and interdependencies of these individual elements during long term storage and disposal. The specific research topics considered were: (i) cementitious materials for radioactive waste packaging: including radioactive waste immobilization into a solid waste form, (ii) waste backfilling and containers; (iii) emerging and alternative cementitious systems; (iv) physical-chemical processes occurring during the hydration and ageing of cement matrices and their influence on the cement matrix quality; (v) methods of production of cementitious materials for: immobilization into wasteform, backfills and containers; (vi) conditions envisaged in the disposal environment for packages (physical and chemical conditions, temperature variations, groundwater, radiation fields); (vii) testing and nondestructive monitoring techniques for quality assurance of cementitious materials; (viii) waste acceptance criteria for waste packages, waste forms and backfills; transport, long term storage and disposal requirements; and finally (ix) modelling or simulation of long term behaviours of cementations materials used for packaging, waste immobilization and backfilling, especially in the post-closure phase. The CRP has gathered overall 26 research organizations from 22 Member States aiming to share their research and practices on the use of cementitious materials [2]. The main research outcomes of the CRP were summarized in a summary report currently under preparation to be published by IAEA. The generic topical sections covered by report are: a) conventional cementitious systems; b) novel cementitious materials and technologies; c) testing and waste acceptance criteria; and d) modelling long term behaviour. These themes as well as all contributions of participating organizations were further developed in the individual reports to be presented in the IAEA publication. The CRP facilitated the exchange of information and research co-operation in resolving similar problems between different institutions and contributed towards improving waste management practices, their efficiency and general enhancement of safety.
Quantifying Tc-99 Contamination in a Fuel Fabrication Plant
Authors: Darbyshire Carol , Burgess Pete
Published: August 2012

The Springfields facility manufactures nuclear fuel products for the UK’s nuclear power stations and for international customers. Fuel manufacture is scheduled to continue into the future. In addition to fuel manufacture, Springfields is also undertaking decommissioning activities. Today it is run and operated by Springfields Fuels Limited, under the management of Westinghouse Electric UK Limited. The site has been operating since 1946 manufacturing nuclear fuel. As part of the decommissioning activities, there was a need was to quantify contamination in a large redundant building. This building had been used to process uranium derived from uranium ore concentrate but had also processed a limited quantity of recycled uranium. The major non-uranic contaminant was Tc-99. The aim was to be able to identify any areas where the bulk activity exceeded 0.4 Bq/g Tc-99 as this would preclude the demolition rubble being sent to the local disposal facility. The problems associated with this project were the presence of significant uranium contamination, the realisation that both the Tc-99 and the uranium had diffused into the brickwork to a significant depth and the relatively low beta energy of Tc-99. The uranium was accompanied by Pa-234m, an energetic beta emitter. The concentration/depth profile was determined for several areas on the plant for Tc-99 and for uranium. The radiochemical analysis was performed locally but the performance of the local laboratory was checked during the initial investigation by splitting samples three ways and having confirmation analyses performed by 2 other laboratories. The results showed surprisingly consistent concentration gradients for Tc-99 and for uranium across the samples. Using that information, the instrument response was calculated for Tc-99 using the observed diffusion gradient and averaged through the full 225 mm of brick wall, as agreed by the regulator. The Tc-99 and uranium contributions to the detector signal were separated using a simple absorber, which essentially eliminated the Tc-99 count rate and reduced the uranium contribution only marginally. The outcome of the project was that it was possible to demonstrate that the complete building met the criterion for acceptance at the local waste facility.
Groundwater Remediation of Hexavalent Chromium Along the Columbia River at the Hanford Site in Washington State, USA
Authors: Foss Dyan L. , Charboneau Briant L.
Published: August 2012

The U.S. Department of Energy Hanford Site, formerly used for nuclear weapons production, encompasses 1500 square kilometers in southeast Washington State along the Columbia River. A principle threat to the river are the groundwater plumes of hexavalent chromium (Cr(VI)), which affect approximately 9.8 square kilometers, and 4.1 kilometers of shoreline. Cleanup goals are to stop Cr(VI) from entering the river by the end of 2012 and remediate the groundwater plumes to the drinking water standards by the end of 2020. Five groundwater pump-and-treat systems are currently in operation for the remediation of Cr(VI). Since the 1990s, over 13.6 billion L of groundwater have been treated; over 1,435 kg of Cr(VI) have been removed. This paper describes the unique aspects of the site, its environmental setting, hydrogeology, groundwater-river interface, riverine hydraulic effects, remediation activities completed to date, a summary of the current and proposed pump-and-treat operations, the in situ redox manipulation barrier, and the effectiveness of passive barriers, resins, and treatability testing results of calcium polysulfide, biostimulation, and electrocoagulation, currently under evaluation.
Safety Assessment Input for Site Selection: The Swedish Example
Authors: Andersson Johan
Published: August 2012

Svensk Ka¨rnbra¨nslehantering AB (SKB) has performed comprehensive investigations of two candidate sites for a final repository for Sweden’s spent nuclear fuel. In March 2011 SKB decided to submit licence applications for a final repository at Forsmark. Before selection, SKB stated that the site that offers the best prospects for achieving long-term safety in practice would be selected. Based on experiences previous safety assessments, a number of issues related to long-term safety need to be considered in the context of site comparison. The factors include sensitivity to climate change such as periods of permafrost and glaciations, rock mechanics evolution including the potential for thermally induced spalling and sensitivity to potential future earthquakes, current and future groundwater flow, evolution of groundwater composition and proximity to mineral resources. Each of these factors related to long-term safety for the two candidate sites is assessed in a comparative analysis of site characteristics. The assessment also considers differences in biosphere conditions and in the confidence of the site descriptions. The comparison is concluded by an assessment on how the identified differences would affect the estimated radiological risk from a repository located at either of the sites. The assessment concludes that there are a number of safety related site characteristics for which the analyses do not show any decisive differences in terms of implications on safety, between the sites Forsmark and Laxemar. However, the frequency of water conducting fractures at repository depth is much smaller at Forsmark than at Laxemar. This difference, in turn, affects the future stability of the current favourable groundwater composition, which combined with the much higher flows at Laxemar would, for the current repository design, lead to a breach in the safety functions for the buffer and the canister for many more deposition positions at Laxemar than at Forsmark. Thereby the calculated risk for Forsmark will be considerably lower than that for Laxemar. What decided the choice is that Forsmark is thus mainly that it was judged to offer better prospects for achieving long-term safety in the final repository. Other factors considered included implications regarding repository construction and operation, difference in the footprint of the repository, comparisons regarding environment and health as well as social resources and local support.
Advanced Surveillance Technologies for Used Fuel Long-Term Storage and Transportation
Authors: Tsai Hanchung , Liu Yung Y. , Nutt Mark , Shuler James
Published: August 2012

Utilities worldwide are using dry-cask storage systems to handle the ever-increasing number of discharged fuel assemblies from nuclear power plants. In the United States and possibly elsewhere, this trend will continue until an acceptable disposal path is established. The recent Fukushima nuclear power plant accident, specifically the events with the storage pools, may accelerate the drive to relocate more of the used fuel assemblies from pools into dry casks. Many of the newer cask systems incorporate dual-purpose (storage and transport) or multiple-purpose (storage, transport, and disposal) canister technologies. With the prospect looming for very long term storage — possibly over multiple decades — and deferred transport, condition- and performance-based aging management of cask structures and components is now a necessity that requires immediate attention. From the standpoint of consequences, one of the greatest concerns is the rupture of a substantial number of fuel rods that would affect fuel retrievability. Used fuel cladding may become susceptible to rupture due to radial-hydride-induced embrittlement caused by water-side corrosion during the reactor operation and subsequent drying/transfer process, through early stage of storage in a dry cask, especially for high burnup fuels. Radio frequency identification (RFID) is an automated data capture and remote-sensing technology ideally suited for monitoring sensitive assets on a long-term, continuous basis. One such system, called ARG-US, has been developed by Argonne National Laboratory for the U.S. Department of Energy’s Packaging Certification Program for tracking and monitoring drums containing sensitive nuclear and radioactive materials. The ARG-US RFID system is versatile and can be readily adapted for dry-cask monitoring applications. The current built-in sensor suite consists of seal, temperature, humidity, shock, and radiation sensors. With the universal asynchronous receiver/transmitter interface in the tag, other sensors can be easily added as needed. The system can promptly generate alarms when any of the sensor thresholds are violated. For performance and compliance records, the ARGUS RFID tags incorporate nonvolatile memories for storing sensory data and history events. Over the very long term, to affirmatively monitor the condition of the cask interior (particularly the integrity of cover gas and fuel-rod cladding), development of enabling technologies for such monitoring would be required. These new technologies may include radiation-hardened sensors, in-canister energy harvesting, and wireless means of transmitting the sensor data out of the canister/cask.
Development of Computer Program for Estimating Decommissioning Cost
Authors: Kim Hak-Soo , Park Jong-Kil
Published: August 2012

The programs for estimating the decommissioning cost have been developed for many different purposes and applications. The estimation of decommissioning cost is required a large amount of data such as unit cost factors, plant area and its inventory, waste treatment, etc. These make it difficult to use manual calculation or typical spreadsheet software such as Microsoft Excel. The cost estimation for eventual decommissioning of nuclear power plants is a prerequisite for safe, timely and cost-effective decommissioning. To estimate the decommissioning cost more accurately and systematically, KHNP, Korea Hydro and Nuclear Power Co. Ltd, developed a decommissioning cost estimating computer program called “DeCAT-Pro”, which is Decommissioning Cost Assessment Tool – Professional. (Hereinafter called “DeCAT”) This program allows users to easily assess the decommissioning cost with various decommissioning options. Also, this program provides detailed reporting for decommissioning funding requirements as well as providing detail project schedules, cash-flow, staffing plan and levels, and waste volumes by waste classifications and types. KHNP is planning to implement functions for estimating the plant inventory using 3-D technology and for classifying the conditions of radwaste disposal and transportation automatically.
Assay of Plutonium Contaminated Waste by Gamma Spectrometry
Authors: Adsley Ian , Green Michael , Pearman Ian , Davies Michael
Published: August 2012

This paper considers the use of two types of gamma detector for the in-situ assay of plutonium contaminated materials (PCM): the thin sodium iodide FIDLER (Field Instrument for the Detection of Low Energy Radiation) and the HPGe (High Purity Germanium) detector. The difficulty of the accurate assay of PCM in the past has led to a default mechanism of collecting such wastes in drums, or other types of containers, for subsequent assessment. This has resulted in many thousands of such drums being collected and stored on the major UK sites which were involved with the handling and processing of plutonium. In some cases these drums have been stored for over 20 years. This paper gives a description of the current technologies for monitoring these stored wastes, but more importantly proposes that it would be a better practice to measure such future PCM wastes in-situ, before any demolition or decommissioning is undertaken.
Waste Minimization by Melting–Recycling of Radioactive Metals: 20 Years Operation of the Melting Plant CARLA by Siempelkamp Nukleartechnik GmbH
Authors: Quade Ulrich , Kluth Thomas
Published: August 2012

Since more than 20 years the company Siempelkamp is deeply involved in the field of melting and recycling of radioactively contaminated metals from operation and decommissioning of nuclear installations across Europe. The experience of this long period shows clearly that only a combination of recycling inside the nuclear industry and release for reuse outside the nuclear market will generate the optimum results for the minimisation of radioactive waste volume. Final disposal volume is becoming more and more the status of an own resource within our nuclear business and should be handled very carefully in the future. The paper gives a compact overview about the impressive results of melting treatment, the current potential of the melting plant CARLA and about further developments.
Set Up of an Environmental Monitoring System, Shchuchye, Russia Technical Assistance
Authors: Belbeze Stephane , Hallouin Matthieu
Published: August 2012

An intergovernmental agreement on cooperation about chemical weapon destruction was signed between France and the Russian federation on 14th February 2006 in the context of a Global Partnership dedicated to preventing catastrophic terrorism and the proliferation of weapons of mass destruction. It came into effect on 25th April 2007 after ratification by both countries. The present demonstrated project was launched as part of this collaboration on the Shchuchye site (Russia – Kurgan Oblast). The project concerned the environmental surveillance system for the Shchuchye site required for the safe operation of the installation used to destroy chemical weapons. The aim was to implement equipments and methods of analysis for very low concentrations of pollutants in the three environmental compartments: air, water and soil. This has been achieved with the help of industry and other organizations in France (Environment/SA for supplies, INERIS and Antea Group) and Russia (ROST Association and EKROS Engineering). This system takes account of the normal operation of the installation as well as incident management. It includes 11 stationary atmospheric measuring stations constructed by Environment/SA and EKROS Engineering including ASTEK dedicated toxic gas detector: “Terminator FOV-1”, 3 mobile atmospheric measuring stations, 2 mobile soil & water measuring stations, 4 sampling cars constructed by Environment/SA and EKROS Engineering, a complete Chemical analysis laboratory which can handle ppb analysis of toxic gases, organics and minerals pollutants, an information collection center and a meteo station which can retrieve, display and archive all the datas or alarm from the stationary and mobile stations. Antea Group has provided a technical expertise and various negotiations during the negotiation phase, the project initiation files & contracts redaction, the project Monitoring and reporting to stakeholders, the REX. Up to 2009, No other site of the world uses such an innovative system. Antea Group worked on this project for 4 years. It successfully began operating in March 2009, before the start of destruction operations, after 15 months of work on the site.
Soils Radiological Characterization Under a Nuclear Facility
Authors: Aubonnet Emilie , Dubot Didier
Published: August 2012

Nowadays, nuclear industry is facing a crucial need in establishing radiological characterization for the appraisal and the monitoring of any remediation work. Regarding its experience in this domain, the French Alternative Energies and Atomic Energy Commission (CEA) of Fontenay-aux-Roses, established an important feedback and developed over the last 10 years a sound methodology for radiological characterization. This approach is based on several steps: - historical investigations; - assumption and confirmation of the contamination; - surface characterization; - in-depth characterization; - rehabilitation objectives; - remediation process. The amount of measures, samples and analysis is optimized for data processing using geostatistics. This approach is now used to characterize soils under facilities. The paper presents the radiological characterization of soils under a facility basement. This facility has been built after the first generation of nuclear facilities, replacing a plutonium facility which has been dismantled in 1960. The presentation details the different steps of radiological characterization from historical investigations to optimization of excavation depths, impact studies and contaminated volumes.
West Valley Demonstration Project High Level, Transuranic, and Greater Than Class C Wastes
Authors: Blankenhorn James A.
Published: August 2012

Located in the scenic hills of Western New York, 35 miles south of Buffalo, the 68 hectare West Valley Demonstration Project (WVDP) is a unique and challenging environmental cleanup project that currently manages High Level, Transuranic, and Greater than Class C wastes. Before the U.S. Department of Energy (DOE) assumed the responsibility of cleaning up the site, the site was the location of the only commercial spent nuclear fuel (SNF) reprocessing facility to operate in the United States. Operated by Nuclear Fuels Services from 1966–72, the site was owned by the State of New York and licensed by the Atomic Energy Commission. During operations, the plant reprocessed approximately 640 metric tons of commercial and defense nuclear fuel. When commercial operations were discontinued and the facilities were returned to New York State, there were nearly 2,271,247 liters (nearly 600,000 gallons) of liquid high-level radioactive waste (HLW) in an underground storage tank, there were approximately 750 unprocessed fuel assemblies, and there was a highly contaminated Main Plant Process Building (MPPB). The West Valley Demonstration Project Act of 1980 (the Act) authorized DOE to conduct a cleanup of the site, in cooperation with the New York State Energy Research and Development Authority (NYSERDA), the State agency responsible for managing the property. The Nuclear Regulatory Commission (NRC) license was placed in abeyance and DOE arrived on site in 1981. Since that time, several significant cleanup milestones have been completed, including vitrification (solidification in a glass matrix) of the high level liquid waste, containing approximately 15 million curies, into 275 high level waste canisters and the disposition of more than 19,000 subsequent drums of low-level radioactive waste (LLW); the shipment of the remaining 125 SNF assemblies that were in storage on site; and the shipment of more than 304,800 cubic meters (1,000,000 cubic feet) of LLW for offsite disposal. More recent accomplishments at West Valley have included deactivation and decontamination of the still-very-contaminated MPPB, management of the underground high level waste tanks (4) and their associated vaults (3), and processing and packaging of both legacy waste and waste generated as a result of decommissioning activities. This paper focuses on the high level, greater than Class C, and Transuranic waste challenges at West Valley and the options to address those challenges.
Dismantling/Remediation of a Highly Contaminated Sump in Running Plant Conditions
Authors: Boussu Jos , Lenie Koen , Coomans Reginald
Published: August 2012

A sump in the RPE circuit in the EDF - Nuclear Power Plant of Cruas-Meysse, showed an extremely high radiation dose rate since 2007. Different attempts to decontaminate the sump did not have the desired effect. The sump is a so-called “gatte” where two flows of different fluida circulates. A chemical flow transverses the sump within stainless steel piping, the second flow which is (contaminated) residual water, flows through this sump in contact with the sumps walls. The dose rate was estimated at 20 Sv/h, and it was presumed being a single hotspot in the dead zone of the sump, where no chemicals from the chemical decontamination attempts and no high pressure water contact had been possible, or had any effect. To protect the maintenance and exploitation people from the radiation, the sump had been protected with a physical protection system, named a sarcophagus. The client asked to leave this protection system, which was modular, on place during the dismantling works to assure its radiation protection function. The paper describes the remote controlled dismantling of the sump within the particular running conditions of the power plant, the developments made to the equipment, and the conditions in which the works had to be carried out. Some lessons learnt and particular points of attention are revealed to complete this paper.
Radiological Evaluation of Contaminated Sites and Soils: VEgAS—An Expertise and Investigation Vehicle
Authors: Attiogbe Julien , De Moura Patrick , Lavielle Marie
Published: August 2012

The “Commissariat a` l’Energie Atomique” (CEA, French Atomic Energy Commission) has set up over the last 10 years an innovative methodology aiming at characterizing radiological contaminations. The application of the latter relies on various tools such as recently developed software platform called Kartotrak which is used in the expertise vehicles with impressive detection performances (VEgAS). A Geographic Information System tailored to radiological needs constitutes the heart of the platform; it is surrounded by several modules dedicated to sampling optimization, data analysis and geostatistical modeling, real-time monitoring (Kartotrak-RT) and validation of proper clean-up operations. This paper presents the purpose and the performances of the VEgAS which provides exhaustive instruments for the radiological surface characterization of sites.