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Characterization of Low Level and Intermediate Nuclear Waste: improvements in calorimetric measurement combined radiological modelling - 16144

Since 40 years, calorimetry allows to determine precisely amounts of nuclear material within a container. Combined with gamma spectrometry, calorimetric measurements give plutonium contents with a low level of uncertainty for each isotope. Calorimetry is used in a lot of nuclear facilities all around the world for plutonium or tritium inventories. It is one of the best solutions to estimate the overall quantity of nuclear material on a wide range of mass, from a few milligrams up to kilograms of radionuclides. In the case of drums containing nuclear waste, characterization was very challenging due to complex matrix, volume and low level activities. The measurement time was a real problem with large volume container and organic matrix with high air content. New designs of SETARAM calorimeters allow to measure nuclear material contents in very large container (up to 385 liters) and/or with a very low detection limit (10 μWatt). These new concepts are based on single measurement cell and vacuum chamber for low level uncertainties. The acquisition system and electronic temperature regulation are highly improved to increase the detection limit, accuracy and precision of the measurement. These modern technological developments within the calorimetry field give the promise of faster measurement times and precise measurements. These devices can be used in waste management of nuclear facilities with a better accuracy and lower uncertainties than others techniques. It is a non-destructive and non-intrusive method. There is no matrix effect which can bias the results. Waste can also be in solid, liquid or gas phase. The new calorimeters are able to give amounts of plutonium, tritium or others alpha or beta emitter radionuclides and allow determining the classification of waste (low level or intermediate). A measurement approach combining very large volume calorimeter, gamma spectrometry and radiological modelling will be presented as an integrated automatic waste characterization system. This system with a calculation step is taking into account the gamma emitters contribution on the total thermal power measured within the calorimeter. The aim of the system is to give a precise quantification of the radionuclides in the waste container with a precise value of the total uncertainties. (authors)

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The analysis of metal melting application in the management of metallic radioactive materials arising from decommissioning of nuclear installations

Basic characterization of the waste management process during decommissioning of nuclear installations is described in the presented paper. A brief description is given of conditional and unconditional release of materials into the environment. The paper deals also with metal melting as prospective decontamination technique which can significantly reduce metallic radioactive waste. The material and radioactivity flow in the decommissioning process should be followed using the integrated material flow tool that is implemented into the standardized analytical decommissioning parameters calculation code OMEGA. Applying the integrated material flow tool, it is possible to monitor radiological and physical properties of individual material items listed in the nuclear installation input database, from dismantling up to their release into the environment or disposal in repository. Using the OMEGA code and two model databases, several scenarios related to metal melting are evaluated. The impact of applying different input decommissioning parameters on the metal distribution is the main result discussed in the paper. (authors)

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Development of the Waste Acceptance Criteria for the Idaho National Laboratory Remote-Handled Low-Level Waste Disposal Facility - 19143

The Idaho National Laboratory (INL) Remote-Handled Low-Level Waste (RH LLW) Disposal Facility has been constructed, has received operational approval from the Department of Energy (DOE), and is expected to receive its first waste shipment in FY 2019. The RH LLW Disposal Facility will support the needs of INL and the Naval Reactors Facility (NRF). RH LLW destined for the facility includes waste currently in storage from previous programs and projects conducted at INL; newly generated waste from programs and projects conducted at INL; and waste from NRF spent fuel processing activities. This new facility supports RH LLW disposal needs for the ongoing mission of INL and NRF. Waste to be disposed of at the RH LLW Disposal Facility may exhibit dose rates that range from 0.002 Sv/hr to 600 Sv/hr. Waste types include resins and activated metals as well as surface-contaminated debris generated from existing and new missions. The total number of canisters currently planned for disposal at the RH LLW Disposal Facility is 939 with the possibility of future expansion. The projected waste volume to be disposed of is 3,100 m{sup 3}. The RH LLW Disposal Facility will receive a wide variety of RH LLW and is in preparations to receive its first canisters in FY 2019. Waste acceptance criteria (WAC) and the radioactive waste management basis have been developed and implemented in accordance with the applicable DOE Order. In order to ensure that DOE requirements and guidance were appropriately implemented in the RH LLW Disposal Facility WAC, the project worked closely with the DOE Low Level Waste Disposal Facility Federal Review Group (LFRG) representatives and followed the applicable DOE standard. This paper provides an overview of the development of the WAC, including waste and waste generator certification requirements, for the RH LLW Disposal Facility. The paper illustrates the importance of maintaining strong ties to the development and revision of the RH LLW Disposal Facility Performance Assessment (PA), Documented Safety Analysis, Facility Procedures, Readiness Reviews, DOE Order, and applicable Technical Standards. The paper also provides an overview of the RH LLW Disposal Facility, WAC generator certification requirements, distinctive challenges to acceptance of legacy waste, and the unique approach the RH LLW Disposal Facility has taken to ensure compliance with PA driven limits. (authors)

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Development and Application of an Oversize Reusable DOT 7A Type A Overpack Container at the Y-12 National Security Complex - 13150

Waste Management personnel at the Y-12 National Security Complex (Y-12) are concluding a multi-year effort to dispose of a large backlog of low-level waste. Six containers presented a particularly difficult technical challenge in that they each contained large robust equipment (mostly salt baths) with elevated levels of highly enriched uranium (exceeding U.S. Department of Transportation (DOT) fissile-excepted quantities). The equipment was larger than the standard 1.2 m x 1.2 m x 1.8 m (4 ft x 4 ft x 6 ft) DOT Specification 7A Type A box and would have been very difficult to size-reduce because of several inches of steel plate (along with insulating block and concrete) in the equipment design. A critical breakthrough for the success of the project involved procuring and developing two oversize reusable DOT Specification 7A Type A (fissile tested) containers (referred to as the CTI Model 7AF-690-SC) that could be used as overpacks for the original boxes of equipment. The 7A Type A overpack containers are approximately 3.5 m long x 2.7 m wide x 2.8 m high (11.7 ft x 8.9 ft x 9.2 ft) with a maximum gross weight of 10,660 kg (23,500 lb) and a payload capacity of 6,804 kg (15,000 lbs). The boxes were designed and fabricated using a split cavity design that allowed the gasketed and bolted closure to lie along the horizontal centerline of the box. The central closure location in this design allows for strengthening of box corners that tend to be points of weakness or failure in 49CFR173.465 drop tests. By combining the split cavity design with large diameter tubing and diagonal cross bracing, drop test requirements of 49CFR173.465(1) and (2) were met and demonstrated through finite element analysis modeling. The development and use of this new container dramatically reduced the need for down-sizing the equipment and allowed the project to meet objectives within cost and schedule targets. (authors)

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Sharing Experiences within AREVA D and D Project Portfolio: Four Illustrations - 13049

Over the past ten years, AREVA has performed D and D operations on a wide range of nuclear sites, such as Marcoule and La Hague recycling plants, to Cadarache MOX fuel fabrication plant or Veurey and Annecy metallic Uranium machining plants. Each site is different from the other but some lessons can be shared through this D and D portfolio. In that respect, knowledge management is one of AREVA D and D Technical Department main missions. Four illustrations demonstrate the interest of knowledge share. Waste management is one of the key activities in D and D; It requires a specific characterization methodology, adapted logistics, and optimized waste channels, all of which have been developed over the years by AREVA teams on the site of Marcoule while they are rather new to La Hague, whose main activity remains fuel reprocessing despite the launch of UP2 400 D and D program. The transfer of know how has thus been organized over the past two years. Plasma cutting has been used extensively in Marcoule for years, while prohibited on the site of La Hague following questions raised about the risks associated wit Ruthenium sublimation. La Hague Technical Department has thus developed an experimental protocol to quantify and contain the Ruthenium risk, the result of which will then be applied to Marcoule where the Ruthenium issue has appeared in recent operations. Commissioning and operating fission products evaporators is a rather standard activity on UP2 800 and UP3, while the associated experience has been decreasing in Marcoule following final shutdown in 1998. When the French atomic Energy commission decided to build and operate a new evaporator to concentrate rinsing effluents prior to vitrification in 2009, AREVA La Hague operators were mobilized to test and commission the new equipment, and train local operators. Concrete scabbling is the final stage prior to the free release of a nuclear facility. In the context of Veurey and Annecy final cleanup and declassification, large scale concrete scabbling operations were conducted, and lead to the industrialization of the process and qualification of a new process, NiThrow{sup TM} scabbling technology, developed by AREVA. This experience has now been injected into La Hague D and D scenario and has allowed a significant gain in time and cost for scabbling operations. In short, the variety of experiences and sites under the responsibility of AREVA D and D teams present significant challenges, and yet provide a unique opportunity to innovate and qualify new tools and methods which can then be shared throughout the sites. (authors)

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Waste collection in developing countries - Tackling occupational safety and health hazards at their source

Waste management procedures in developing countries are associated with occupational safety and health risks. Gastro-intestinal infections, respiratory and skin diseases as well as muscular-skeletal problems and cutting injuries are commonly found among waste workers around the globe. In order to find efficient, sustainable solutions to reduce occupational risks of waste workers, a methodological risk assessment has to be performed and counteractive measures have to be developed according to an internationally acknowledged hierarchy. From a case study in Addis Ababa, Ethiopia suggestions for the transferral of collected household waste into roadside containers are given. With construction of ramps to dump collected household waste straight into roadside containers and an adaptation of pushcarts and collection procedures, the risk is tackled at the source.

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Remote Retrieval, Disruption and Processing of Legacy Nuclear Waste - 16179

The UK National Nuclear Laboratory (NNL) is currently undertaking, in conjunction with Sellafield Ltd, a series of high profile trials of robotic equipment on a full scale test facility at their Workington Laboratory in England. These trials are designed to underpin and substantiate the processes proposed for the remote retrieval, disruption and processing of legacy Miscellaneous Beta Gamma Waste (MBGW) from a number of different donor plants on the Sellafield site, including some of the older fuel storage ponds and storage silos. These processes will be conducted inside the new Box Encapsulation Plant (BEP) which is due to be commissioned at Sellafield by 2020. These processes will subsequently enable Sellafield Ltd to safely recover legacy Intermediate Level Waste (ILW) from the older storage facilities on site and process it into a safer form which is more suitable for long term storage and then ultimately final disposal in a Geological Disposal Facility. As part of this legacy waste processing within the BEP plant, MBGW waste items will have to be remotely removed from a variety of different types of import skips. This waste will then be transferred, using robots, into the export container, which is a 3 m{sup 3} box liner, where the processed waste will be flood grouted to produce an encapsulated waste package. As part of this processing, any MBGW items consisting of sealed containers will have to be remotely disrupted before being grout encapsulated. This disruption is in order to (a) release any trapped liquors or gases from the containers and (b) ensure full grout infiltration of the container contents, thus minimising the amount of free liquors and voids within the final waste product. The NNL are conducting this technical work to confirm the viability of the proposed concept, processes and equipment. The developed solution consists of a linear layout of processing equipment with a pair of heavy duty, standard industrial, 'commercially off the shelf' (COTS) robots positioned around a Waste Handling Table. These robots have a 500 kg payload capacity and are operated remotely to handle all of the various types of MBGW waste, including the heavy and bulky items. The robots can be operated in manual tele-operation mode as well as pre-programmed automatic mode and have a range of primary and secondary tooling in order to perform the waste processing and disruption tasks as well as undertake general house-keeping and cleaning duties within the cell. The main tools include two types of hydraulic grab for the main waste recovery and handling tasks and a hydraulic shear for the waste disruption activities, but a number of other tools have also been designed and built for ancillary activities, such as a set of general purpose gripper jaws, drilling tool, bolt removal tool, pump tool, spray tool and a number of different housekeeping tools etc. The robot trials were started in November 2014, and have attracted a significant degree of high level stakeholder interest, including the UK Nuclear Decommissioning Authority (NDA), Office for Nuclear Regulation (ONR), Environment Agency (EA) and Radioactive Waste Management Limited (RWML) witnessing a number of the critical demonstration trials. Robots of the type selected are readily available, robust, reliable and easy to use. The trials have been very successful in proving the retrieval, processing and disruption operations, reducing the burden in the legacy waste facilities. Utilising robots to perform these tasks will lower the probability of producing non-compliant waste packages. In addition the robots can increase the consolidation of incoming waste skips into outgoing 3 m{sup 3} box liners, significantly increasing packing efficiencies and reducing the overall number of export containers produced thus lowering the decommissioning and waste storage/disposal costs. The trials have also enabled an assessment of the optimum way to operate the robots, as well as their reliability and maintainability issues. Engineering work associated with recovering failed robots and removing them from a typical Sellafield plant environment and then subsequently replacing them with functioning robots has also been undertaken and further work is now planned. The success of the trials, completed safely to a very challenging timescale, has enabled the use of robots in BEP to be endorsed as a viable option by the key stakeholders. Following a robust decision making process, this was a clear cut decision. The technical development and testing of the robot technology is currently continuing in order to investigate areas such as robot reliability, failure recoveries, human factors, ease of waste identification, optimisation of throughput rates, nuclearisation modifications etc. (authors)

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Arvia organics destruction: an innovative treatment approach for dioxins, furans and other problematic (Orphan) organic wastes - 15380

The safe and efficient disposal of radionuclide-contaminated organic wastes is a key component in the life-cycle of a nuclear power plant. Technologies are available for the processing of some of these wastes although there are a number of waste streams for which the disposition path is not clear or does not exist at all. For example, waste streams such as dioxin, furan and PCB-laden oils pose an issue for the US Dept. of Energy complex. These wastes present a challenge as they cannot be readily treated using existing treatment technologies because of legislative and material constraints such as gaseous phase radioactivity discharge limits, waste elemental content, by-product generation and waste resistance to thermal decomposition. Alternate methods of organics destruction can circumvent some of these issues by using different mechanisms of organics oxidation. One such innovative method, known as the Arvia organics destruction process, combines adsorption with electrochemical combustion and offers such an alternative. This technology, based on a patented material, Nyex{sup TM} that is able to act as both an adsorbent and as an electrode, allows the electrochemical combustion of adsorbed organics to occur on the material's surface. The result is the destruction of organics whilst the bulk of inorganic and radionuclide components remain in the aqueous phase. These components can subsequently be treated using existing waste processing technologies. This paper outlines recent work conducted on demonstrating the Arvia process against the destruction of dioxin, furan and PCB-laden wastes that demonstrates that the technology successfully removes these target species to below discharge standards in the aqueous phase. Based on these successful trials a test unit has been designed to demonstrate the process on actual radioactive wastes at the DOE Oak Ridge facility. The successful treatment of F027-coded waste has also been demonstrated and will be reported. The above work showcases the development, scaling and application of an innovative technology, first presented to the industry at the Waste Management Symposia in 2012, as another option for the treatment of challenging wastes with expensive, complex or no current disposal routes. The Arvia process adds to the portfolio of available treatment technologies and will help facilitate the decommissioning and waste disposal responsibilities of the nuclear industry. (authors)

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Application of polymers for the emergency damage control and remediation at nuclear and chemical industry sites - 15259

From the standpoint of possible accidents and the following complex emergency damage control the nuclear and chemical industry sites are of the primary concern. Among the possible causes of accidents and emergency situations are technological and waste solution spills. Polymers can be used for this problem resolution and the spilled solutions could be effectively isolated. The apparent advantage of polymer materials is the possibility of solidifying solutions with rather high acidity and high salt bearing. To date the situations with the RW storage tank decommissioning in Russia and in the United States have much in common: the lack of the waste management strategy developed at the initial stage of production, the end of the storage tank lifetime. Development of the in-situ solidification technique for the mobile (liquid) components of heterogeneous waste will provide a good option to contain the radio nuclides within the storage site boundaries. The presented work was aimed at the search for the simple engineering decisions that would provide the waste immobilization in case of the accidental liquid spills. The application of polymers for the purpose indicated would allow in case of emergency to reduce the radioactive aerosol concentration in the air and prevent the distribution of aerosols on the premises and in the environment. Another promising area of the polymer application could be the technical challenges associated with the decommissioning of NPPs and other objects and facilities including the large volume LRW storage tanks. (authors)

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Remote Dismantling and Packaging of the RPV and Thermal Shield at the Obrigheim NPP - 16073

The Obrigheim Nuclear Power Plant (KWO) is located in the Federal State of Baden- Wuerttemberg in Germany and was operated by the EnKK-KWO. The Nuclear Power Plant - a light water pressurized water reactor with 357 MW of electrical power - was operated from 1968 to 2005. In June 2009 the Energiewerke Nord GmbH (EWN) was charged with the dismantling planning and dismantling of the reactor. According to the German nuclear and radiation protection law, several licenses will be required for the realisation of this task. This also applies to the disposal of the waste produced by dismantling, which must finally be stored in the German final repository for low and medium-radioactive waste (underground repository 'Konrad'). In spring 2010 EWN completed all application documents for the dismantling of the reactor pressure vessel (RPV) and the RPV internals and EnKK-KWO delivered them to the responsible Environmental Ministry of Baden-Wuerttemberg. Since then it has been worked intensively on the design, construction and manufacturing of the facilities for dismantling. With a separate notification of amendment, it was applied for the license to install and commission the facilities for the dismantling of the RPV and the RPV internals at the Environmental Ministry of Baden-Wuerttemberg in October 2010. This notification of amendment was confirmed in summer 2012. In September 2011 the work process and test plan and the technical information about the campaign for the removal of the radioactive waste resulting from the RPV with internals, peripheral components and secondary waste with the aim of final disposal in the Federal Repository 'Konrad' was submitted to the Federal Office for Radiation Protection. The evaluation and assessment of the work process and test plan was concluded in August 2013, when it was audited by TUV Nord EnSys without any further measures and indications. On September 10 the work process and test plan was released by the Federal Office for radiation protection. The dismantling of the RPV internals upper core and lower core structure started in September 2013 in the wet cutting area in room 01.106/306 and were finished in October 2014. In the presentation 'Dismantling of the Obrigheim NPP Reactor and Waste Management' held on the WM Symposia in Phoenix, 2014, an overview about the remote cutting and packaging of the upper and lower core structure was given. In today's presentation the subsequent dismantling activities will be outlined and evaluated. The presentation will start with the short description of the basic frame conditions for the nuclear licensing procedure, important procedural principles, and necessary plant-specific conditions. After the remote cutting and packing of the reactor internals of the upper and lower core structure was completed, the wet cutting area 'reactor room 01.106/306' was cleaned and the reactor room rebuilt into a cutting area for peripheral components. After the peripheral components were dismantled, all preconditions were set to lift the RPV from its mounting position and to arrange it in the upper reactor room 01.306. After these activities were completed, the lifting of the RPV was prepared and the cutting area 'Dismantling of the RPV insulation in the reactor room 01.106/306' was set up. To carry out this task, a strand jack unit with connection block was installed on the bridge of the reactor building crane. The opening created by the dismantling of the pool plate was closed with a flap door. The manipulators used for the wet cutting of the RPV internals were also used for the remote dismantling of the RPV insulation and mounted in the cutting area. The remote facilities were handled from a control centre and/or control stand. The air-technical housing which has already been used for the remote dismantling of the RPV internals was designed for the dismantling of the RPV insulation and was extended for this dismantling scope with appropriate ventilation systems. A special feature is the fixation of the RPV insulation at the RPV corpus. The RPV insulation consists of insulation wool, wire mesh and metal-sheet insulation. This 'Sandwich Construction' is detached with a steel corset at the RPV corpus and partly tightened. The insulation of the RPV bottom dome is tightened at the supporting frame. Due to the activation of the material in the core area and the resulting high ambient dose rate the RPV insulation can only be dismantled remotely. Additionally, as asbestos fibers are expected to be found in the insulation the dismantling has to be performed according to the Technical Rules for hazardous substances. The demolition, restoration or maintenance works have to be performed remotely according to the Technical Rules for hazardous substances when the RPV is located in the cutting area. But in case of dismantling of a power reactor no such experience can be found. Beginning with the explanation of the technical, radiological and substantial boundary conditions this presentation will not only impart knowledge about the dismantling of the RPV insulation but also about the remote controlled packaging of the metal sheet insulation and the manual conditioning of the RPV insulation. Subsequently, reports on the remotely controlled cutting and packaging of the RDB are given. Here is particularly interesting that cutting methods have been used and how the activity determination of the segments was carried out. On the basis of the evaluation of the realisation the subsequent dismantling activities will be lined out. In parallel to the dismantling tasks, the waste package documentation for the final repository was issued, checked and confirmed for the containers loaded with parts of the RDB internals. The most important stages are exemplified in this presentation. (authors)

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2015 Annual Summary Report for the Area 3 and Area 5 RWMs

This annual summary report presents results and conclusions of the Fiscal Year (FY) 2015 review to assess the adequacy of the performance assessments (PAs) and composite analyses (CAs) in support of the Disposal Authorization Statements for the Area 3 and Area 5 Radioactive Waste Management Sites at the Nevada National Security Site (NNSS). The report presents results and conclusions of the FY 2015 review and determines the adequacy of the PAs and CAs. Operational factors (e.g., waste forms and containers, facility design, and waste receipts), closure plans, monitoring results, and research and development (R&D) activities were reviewed to determine the adequacy of the PAs. Likewise, the environmental restoration activities at the NNSS relevant to the sources of residual radioactive material that are considered in the CAs, the land-use planning, and the results of the environmental monitoring and R&D activities were reviewed to determine the adequacy of the CAs.

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Development of Processing Technology for Radioactively Contaminated Water at Chernobyl Nuclear Power Plant - 19656

During the operation of the Chernobyl Nuclear Power Plant, distillation by evaporation was the main method for processing radioactively contaminated water. When the plant was decommissioned, the evaporation facility was mothballed and floor drain treatment was suspended in 2016. At present, the existing tanks with the capacity of 26,000 m{sup 3} are more than 60% full with radioactively contaminated floor drains, which requires alternative processing methods. The current process flow for radioactive waste management at State Specialized Enterprise 'Chernobyl NPP' includes processing of accumulated liquid radioactive wastes at a liquid radioactive wastes processing plant. Under the processing technology, liquid radioactive waste is immobilized at the plant by cementation and the resulting solid radioactive waste is then buried in a near-surface storage. Key factors for the selection of alternative radioactively contaminated water processing methods are the possibility to clear the processed water (no control monitoring), which requires the same degree of processing as for drinking water, and minimization of radioactive waste generation due to the lack of free space for solid waste disposal in the near-surface storage. Floor drains that require processing contain radionuclides such as {sup 137}Cs, {sup 90}Sr, {sup 60}Co and {sup 40}K. The current level of the total beta and gamma activity is about 4*105 Bq/kg. The following criteria are set for the Chernobyl NPP site for water to be disposed to the sewerage system: - Max. 37 Bq/kg for the total beta and gamma containing radionuclide activity; - Max. 0.7 Bq/kg for the total alpha containing radionuclide activity. METOIL produces inorganic sorbents for removing radionuclides from liquids and develops sorbent-based technology for a variety of applications related to liquid radioactive waste processing. In 2017-2018, experts from the Chernobyl NPP and METOIL ran several joint laboratory tests to evaluate the efficiency of inorganic sorbents made by METOIL for processing floor drains at the Chernobyl NPP. The test procedure included treatment of radioactively contaminated water in a two-stage sorption process: static sorption (sorbents are mixed in a liquid) and dynamic sorption (the liquid is filtered through a sorbent column). NIKET and MODIKS sorbents were provided for the tests. The results of the test measurements showed that the total alpha containing radionuclide activity is less than 0.026 Bq/kg and the total beta and gamma containing radionuclide activity is 9.2 Bq/kg. The physical and chemical parameters after processing also met the water disposal criteria. High sorption capacity of the sorbents used for the tests allows processing hundreds of water volumes with just one sorbent volume. At present, preparations are underway for full-scale tests at a pilot plant with a capacity of minimum 10 m{sup 3}/day. At a later stage, spent sorbents may be immobilized by inclusion into the cement matrix, which will substantially reduce the amount of radioactive waste to be buried. (authors)

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Development of a specific methodology to assess suitable sites to receive a repository for L/ILW waste in the Portuguese territory

Portugal does not have nuclear power plants but records an increasing production of radioactive waste from medical, industrial and research applications of radioactive materials in the form of sealed and unsealed sources; the country totals include also the spent fuel of one nuclear reactor for research purposes. Since radioactive waste management policies and practices in Portugal will have to comply with the Council Directive 2011/70/Euratom and the IAEA Joint Convention, the search for scientific and technological solutions to deal with radioactive wastes produced in the country started some years ago. The research carried out recently under the scope of a national funded project (KADRWaste, PTDC/CTEGEX/ 82678/2006) represents a firm step in this commitment. Indeed, the transfer of methodologies tested and validated in this project allowed for improvement to a procedure to assess suitable sites to receive a near-surface repository for 'Low and Intermediate Level Waste, Short Live and Long Live' (LILWSL, LL) wastes in Portugal mainland. Although the main stages of the procedure can be of universal usage, details were designed according to the intrinsic geological, geomorphic and meteorological features of previously selected target-areas. All the requirements exhaustively listed in many reports of the IAEA were fulfilled and, in addition, the application of mineralogical, geochemical and textural criteria is strongly advised. The proposed procedure is based on a 5 key-steps approach preceded by clarification of the boundary conditions to be imposed, which are crucial to the inventory of various compulsory technical requirements. This analysis requires the adoption of stringent criteria, many of them of multidisciplinary nature, including tests of vulnerability and assessment of uncertainty, besides the environmental impact risk. As a result, priority targets that are not excluded will integrate different classes and, depending on the existing knowledge, it will be possible to select locations suitable for the repository installation, taking into account also the political, social and administrative dimensions behind this decision. (authors)

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Pyrolysis reaction models of waste tires: Application of Master-Plots method for energy conversion via devolatilization

Highlights: • Pyrolysis kinetics of waste tire was studied. • Activation energy was obtained using model free methods. • Master Plots were used to predict pyrolysis reaction model. • Reaction model was in a good agreement with experimental data. - Abstract: Land applied disposal of waste tires has far-reaching environmental, economic, and human health consequences. Pyrolysis represents a potential waste management solution, whereby the solid carbonaceous residue is heated in the absence of oxygen to produce liquid and gaseous fuels, and a solid char. The design of an efficient conversion unit requires information on the reaction kinetics of pyrolysis. This work is the first to probe the appropriate reaction model of waste tire pyrolysis. The average activation energy of pyrolysis was determined via iso-conversional methods over a mass fraction conversion range between 0.20 and 0.80 to be 162.8 ± 23.2 kJ mol{sup −1}. Using the Master Plots method, a reaction order of three was found to be the most suitable model to describe the pyrolytic decomposition. This suggests that the chemical reactions themselves (cracking, depolymerization, etc.), not diffusion or boundary layer interactions common with carbonaceous biomasses, are the rate-limiting steps in the pyrolytic decomposition of waste tires.

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The CNSC's Inspector Training and Qualification Program and its Importance to the Nuclear Industry - 19370

Trained, qualified, and designated staff at the Canadian Nuclear Safety Commission (CNSC) conduct inspections of licensed nuclear sites as a method of compliance verification. This paper will describe the unique and comprehensive qualification process for CNSC inspectors, known as the Inspector Training and Qualification Program (ITQP). The ITQP includes service-line-specific training that is unique to each inspection group within the CNSC, dependent on the facility/industry type. The training requirements specific to staff in the Wastes and Decommissioning Division and its impact on safety at waste management sites across Canada will be discussed. This paper will specifically identify the importance of CNSC inspector training and detail how the unique training program requirements enable the CNSC to better identify and encourage compliance among nuclear waste and decommissioning sites in Canada. CNSC inspectors are designated under section 29 of the Nuclear Safety and Control Act (NSCA), and the powers of inspectors are outlined in section 32 of the NSCA. Having trained, qualified, and designated inspectors is paramount for both the CNSC and the nuclear industry. For the CNSC, this ensures that staff in the field are aware of potential hazards and how to mitigate such hazards (if applicable), that staff understand the regulatory framework and how to measure compliance against it, and that staff consistently apply CNSC values across the nuclear industry. For the industry, this ensures that staff present at nuclear facilities are knowledgeable and professional, that inspections are conducted in a consistent manner, and that any compliance actions issued are measurable and defendable against the regulatory framework. The CNSC's ITQP incorporates both theoretical (in-class and online) and practical training, and is broken down into six categories: mandatory training for all new employees; core training; service-line-specific training; on-the-job training; CNSC regulations training; and, recommended additional training. This paper will discuss in detail the specific aspects of each of these categories, the importance of each category including the difference between knowledge and skills acquired in theoretical versus hands-on training, and how CNSC staff in designated inspector positions (inspectors-in-training) progress through the program. The complete list of core training and service-line-specific training for inspectors in the Wastes and Decommissioning Division, including re-qualification requirements, will be explored throughout the paper. It is further important that CNSC designated inspectors undergo continuous learning to ensure that their skills remain up to date, as well as to ensure that inspectors requalify at defined intervals to enable the maintenance of the core knowledge and skills with which the determination of the person's qualification was based. The steps involved in this requalification process, as well as the importance of continuous learning and the maintenance of skills and knowledge will be further discussed. (authors)

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Transport and Treatment of Chapelcross Gas Ducts for Clearance and Recycling - 19662

In the summer of 2018, Cyclife, the EDF group's specialist radioactive waste management and decommissioning company, transported sixteen gas ducts and associated equipment from the shutdown Chapelcross nuclear power plant to treatment facilities in the UK and Sweden. The client requested a full removal, treatment and disposal service for approximately 820 te of low level metallic waste comprising Upper Gas Duct Assemblies (including bellows), Upper Gas Duct elbows, Filter Pots and Convoluted pipework. The complex scope involved heavy lifting, transport by road and sea, processing and recycling on a large scale, thereby necessitating involvement of a wide range of suppliers at different tiers all managed by Cyclife. The purpose of the entire project was to safely handle and treat all of the components for clearance and recycling into the public domain for the manufacture of new steel products. Most of the treatment took place in Cyclife's nuclear licensed metal treatment facility in Sweden. Cyclife has a long and unique experience of arranging safe transport of large contaminated components on road and sea. The metal treatment facility in Sweden can, without special arrangements, receive components up to 30 meters long with a weight of up to 400 tonnes for decontamination, size reduction and melting. The actual treatment of the components consisted of the following steps: a) Separation of a gas duct from the gantry, b) size reduction, radiological verification measurements and clearance of the gantry, c) stepwise segmentation of the gas duct and elbow including removal of asbestos, d) decontamination, e) melting, f) radiological assessment and clearance of the metal ingots, g) management of the secondary waste for return to UK. The result of the project, upon completed treatment of all the material, demonstrates a high recycling rate of the material. 5-10% of the original mass of material will have to disposed as radioactive waste. This number include all residues, untreatable material (asbestos, mineral wool, filters etc.) and two melt batches with a too high activity content for clearance. The paper takes the reader through the entire project from the initial planning to the clearance of the metal and the return of the secondary waste to UK for disposal. It will also present and discuss pros and cons for alternative management approaches in several perspectives. (authors)

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Update to the Performance Assessment for the Savannah River Site Saltstone Disposal Facility - 20124

In 2019, Savannah River Remediation developed a revision to the performance assessment (PA) on behalf of the U.S. Department of Energy (DOE) Savannah River Operations Office (SR) for the near-surface disposal of low-level waste at the Savannah River Site (SRS) Saltstone Disposal Facility (SDF). Soluble waste from SRS Tank Farms undergoes salt processing to remove cesium and other high activity constituents. The low-activity decontaminated salt solution (DSS) is then immobilized by mixing it into a cementitious waste form known as saltstone. After mixing, the saltstone is poured into leak-tight concrete vaults, known as saltstone disposal units (SDUs), where the waste form cures. By the time of facility closure, the SDF is expected to consist of 15 SDUs with a combined capacity of 1.06 E+09 L (280 Mgal) of cured saltstone. The facility operates under a Disposal Authorization Statement (DAS) from DOE and a permit from the South Carolina Department of Health and Environmental Control (SCDHEC). Since the start of operations in 1990, the SDF has received almost 6.7 E+07 L (18 Mgal) of DSS, resulting in the safe disposal of 2.7 E+16 Bq (7.3 E+05 Ci) of activity. Due to the radioactive decay of short-lived contaminants, the total remaining activity in the disposed waste is estimated to be approximately 1.4 E+16 Bq (3.9 E+05 Ci), as of September 2018. The Disposal Authorization Statement requires a demonstration that the system of engineered and natural features of the disposal facility will limit releases from the facility and be protective of human health and the environment for at least the next 1,000 years. The long-term performance of the facility was evaluated under the requirements of the DoE's Radioactive Waste Management Manual (US DOE Manual 435.1-1). Simulations were performed to demonstrate that the disposal facility would meet performance objectives specified in the manual. The evaluation was based on numerical models that simulate the releases of contaminants from the saltstone waste form. Contaminants were transported through groundwater and air pathways to points of assessment to evaluate compliance. In addition, the potential consequences of an inadvertent human intrusion (IHI) were also evaluated. In accordance with the guidance and recommendations in US DoE's technical standard for DAS, deterministic and probabilistic analyses were performed to demonstrate the SDF system, which includes the engineered cover system, the SDUs, the waste form, and the natural features of the site, provides a reasonable expectation that saltstone disposal will meet performance objectives. Post-closure doses to future members of the public (MOP) were evaluated; dose estimates from the air pathway were well below the 1.0 E-04 Sv/yr (10 mrem/yr) performance objective within 1,000 years, and the calculated doses to the MOP from all exposure pathways, including the groundwater and air pathways, were well below the 2.5 E-04 Sv/yr (25 mrem/yr) performance objective within 1,000 years. Doses following an assumed intrusion event within the facility boundaries were well below the IHI performance objectives, where the acute IHI dose was below the acute IHI dose performance objective of 5.0 E-03 Sv (500 mrem) and the chronic IHI dose was below the chronic IHI dose performance objective of 1.0 E-03 Sv/yr (100 mrem/yr) within 1,000 years. (author)

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4th Quarter Transportation Report FY 2014: Radioactive Waste Shipments to and from the Nevada National Security Site (NNSS)

This report satisfies the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Field Office (NNSA/NFO) commitment to prepare a quarterly summary report of radioactive waste shipments to and from the Nevada National Security Site (NNSS) Radioactive Waste Management Complex (RWMC) at Area 5. There were no shipments sent for offsite treatment and returned to the NNSS this quarter. There was one shipment of two drums sent for offsite treatment and disposal. This report summarizes the 4th quarter of Fiscal Year (FY) 2014 low-level radioactive waste (LLW) and mixed low-level radioactive waste (MLLW) shipments. This report also includes annual summaries for FY 2014.

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