[en] A study on the development of gas ventilation system for the LILW disposal facility is under research by Korea Radioactive Waste Agency and the concept of gas permeable seal has been adapted as gas ventilation system from the study. The material of gas permeable seal is S/B (Sand/Bentonite) mixture referred to the international cooperative research. For the performance evaluation of gas permeable seal, the lab-scale performance experiment has been designed. It is expected that nitrogen gas will penetrate S/B mixture than the concrete specimen since the gas permeability of S/B mixture is higher than that of the concrete specimen as designed. With the result, the performance of S/B mixture as gas permeable seal would be verified. As the effective gas ventilation system is applied on the design of concrete silo, the integrity of engineered barrier in the disposal facility would be improved against the overpressure by generated gases. After closure of the LILW (Low- and Intermediate-Level radioactive Waste) disposal facility, the concrete silo will be saturated with ground water. Thus, ground water will contact with waste drums, so that various gases will be generated from several reactions such as metal corrosion, radiolysis and so on. In order to prevent the overpressurization of concrete silo by generated gases, the gas ventilation system should be applied into the design of silo

[en] The result of this study means that we have a possible new method for cheap and less wasteful nuclear waste decontamination. When severe accidents such as the incident at the Fukushima nuclear site occur, the soil near the power plant is contaminated with fission products or the activation metal structure of the power plant. The soil pollution form depends on the environment and soil characteristics of the contaminated areas. Thus, a- single-decontamination method is not effective for site cleanup. In addition, some soil decontamination methods are expensive and large amounts of secondary waste are generated. Therefore, we need new soil decontamination methods. In this study, instead of using a conventional solvent method that generates secondary waste, supercritical carbon dioxide was used to remove metal ions from the soil. Supercritical carbon dioxide is known for good permeation characteristics. We expect that we will reduce the cost of soil pollution management. Supercritical carbon dioxide can decontaminate soil easily, as it has the ability to penetrate even narrow gaps with very good moisture permeability. We used TBP, which is a known for extractant of actinium metal. TBP is usually used for uranium and strontium extraction. Using TBP-HNO₃ complex and supercritical carbon dioxide, we did extraction experiments for several heavy metals in contaminated soil

[en] New composite fibers are synthesized by in situ deposition of potassium-nickel ferrocyanide layer on the surface of modified pyridylacetonitrile fibers. The data of electron microscopic and infrared investigations confirmed the formation of the ferrocyanide layer on the fiber' surface

[en] Nuclear power plays a key role in limiting European Union’s greenhouse gases emissions, and makes an important contribution to improve EU’s independence, security and diversity of energy supply. However, its social acceptance is closely linked to an enhanced safety in the management of long-lived radioactive waste contributing to resource efficiency and cost-effectiveness of this energy and ensuring a robust and socially acceptable system of protection of man and environment. Among the different strategies, partitioning and transmutation (P&T) allows a reduction of the amount, the radiotoxicity and the thermal power of these wastes, leading to an optimal use of geological repository sites. ACSEPT successfully addressed the partitioning issues by focusing on the development of advanced separation processes, both aqueous and pyrochemical. Head-end steps, fuel refabrication, solvent treatment, waste management were also taken into account. In aqueous process development, the SANEX, innovative SANEX and GANEX flowsheets were designed and tested in hot cells. In pyrometallurgy, studies on actinide back-extraction from aluminium and exhaustive electrolysis allowed the validation of two flowsheets developed from more then 10 years in Europe. A training and education program including seminars, workshops, brainstorming meeting but also student exchanges and support to post-doctorate fellowships was a key point for maintaining and increasing a high expertise level in actinide separation sciences in Europe. Six month after the end of ACSEPT, and when its follow-up, SACSESS, just begins, it is time to highlight its main achievements. (author)

[en] The whole cycle of the decommissioning process development of repository requires the relevant bodies to have a financial system to ensure that it has sufficient funds for its whole life cycle (over periods of many decades). Therefore, the financing mechanism and management system shall respect the following status: the national position, institutional and legislative environment, technical capabilities, the waste origin, ownership, characteristics and inventories. The main objective of the studies is to focus on the cost considerations, alternative funding managements and mechanisms, technical and non-technical factors that may affect the repository life-cycle costs. As a conclusion, the outcomes of this paper is to make a good recommendation and could be applied to the national planners, regulatory body, engineers, or the managers, to form a financial management plan for the decommissioning of the Nuclear Installation

[en] The sorption of Ni(Ⅱ) on bentonite was studied by using batch technique. The effects of contact time, pH, ionic strength, bentonite content and humic acid on the sorption of Ni(Ⅱ) on bentonite were investigated. The results suggest that the sorption of Ni(Ⅱ) on bentonite is strongly dependent on ionic strength at low pH, and independent on it at high pH. The sorption of Ni(Ⅱ) at low pH is mainly dominated by ion exchange and/or outer-sphere surface complexation, whereas the sorption of Ni(Ⅱ) at high pH is mainly dominated by inner-sphere surface complexation. The presence of humic acid in the system enhances Ni(Ⅱ) sorption to HA-bentonite hybrids at low pH, but reduces sorption of Ni(Ⅱ) on HA-bentonite hybrids at high pH. (authors)

[en] Simulated radioactive spent resins were solidified by sulfoaluminate cement, and the influence of water/binder ratio and the blending amount of naphthalene-based water reducer UNF-5 on fluidity, setting times and compressive strength of waste forms were investigated. With water/binder ratio increasing from 0.25 to 0.35, the fluidity enhances linearly from 228 mm to 280 mm. The initial and final setting time prolong from 3.0 h and 9.3 h to 4.6 h and 10.4 h, respectively. The 28 d compressive strength decreases linearly from 19.8 MPa to 13.5 MPa. When the blending amount of UNF-5 increases, the fluidity increases, the setting time decreases initially and then increases, and the compressive strength increases to the maximum and then decreases. With UNF-5 blending amount of 0.05%-0.10%, the fluidity is 200-225 mm, the initial and final setting time are 3-4 h and 11-12 h, respectively, and the 28 d compressive strength is 21.1-21.7 MPa. (authors)

[en] Licence applications to build a repository for the disposal of Swedish spent nuclear fuel have been lodged, underpinned by myriad reports and several broader reviews. This paper sketches out the technical and administrative aspects and highlights a recent review of the biosphere effects of a potential release from the repository. A comprehensive database and an understanding of major fluxes and pools of water and organic matter in the landscape let one envisage the future by looking at older parts of the site. Thus, today's biosphere is used as a natural analogue of possible future landscapes. It is concluded that the planned repository can meet the safety criteria and will have no detectable radiological impact on plants and animals. This paper also briefly describes biosphere work undertaken after the review. The multidisciplinary approach used is relevant in a much wider context and may prove beneficial across many environmental contexts. (authors)

[en] Radioactive waste management in the post-accidental phase following caring for a radiologically contaminated patient in a hospital decontamination facility must be anticipated at a local level to be truly efficient, as the volume of waste could be substantial. This management must comply with the principles set out for radioactive as well as medical waste. The first step involves identification of radiologically contaminated waste based on radioactivity measurement for volume reduction. Then, the management depends on the longest radioactive half-life of contaminative radionuclides. For a half-life inferior to 100 days, wastes are stored for their radioactivity to decay for at least 10 periods before disposal like conventional medical waste. Long-lived radioactive waste management implies treatment of liquid waste and special handling for sorting and packaging before final elimination at the French National Agency for Radioactive Waste Management (ANDRA). Following this, highly specialized waste management skills, financial responsibility issues and detention of non-medical radioactive sources are questions raised by hospital radioactive waste management in the post-accidental phase. (authors)

[en] Savannah River enjoyed two years of increased funding as a result of the American Reinvestment and Recovery Act and Department of Energy (DOE) directed scope additions. Moving into FY2012, a much lower funding level is anticipated. In the past, the first response to a reduced funding scenario was to defer scope and slow down the program. This time, Savannah River decided that a better process was needed to try to maximize value to the government. This approach was named the Cost Savings Initiative (CSI). The CSI process is similar to a zero-based budget concept. Every element of work scope was screened to eliminate everything that was not directly related to safety and regulatory compliance. Then the schedules for the regulatory-driven scope were deferred such that the regulatory milestones were achieved just in time with no acceleration. This resulted in a strategy that met regulatory requirements in FY2012-13 with some remaining funding but not in FY2014-15. The remaining funding was then invested in cost savings initiatives in FY2012-13 to reduce the future cost of doing business in the FY2014-15 timeframe and beyond. This resulted in a Strategy that: - Meets all regulatory commitments; - Meets some regulatory commitments early; and - Preserves most of the life cycle savings that were built in to the baseline plan The CSI process used at Savannah River may be considered for application elsewhere in the DOE Complex. (authors)