Radioactive Waste Storage Facility Research Articles

Influence of SR-90 on the Morphometric Indices and the Level of Proteins of Metallothioneins in the Soft Tissues of Terrestrial Mollusks Bradybaena Fruticum in the Area of Location of the Regional Radioactive Waste Storage Facility

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Risk discourses and governance of high-level radioactive waste storage in Taiwan

Policy scholars have indicated that the quality of the solution to a perceived social problem depends on the adequacy of its framing. This paper examines how policy stakeholders and local residents frame the issue of the radioactive waste storage facility in Taiwan, the limits of institutional mechanisms in decision-making processes, and the implications of the deliberative forums undertaken by the national Stop Nukes Now organisation. The controversy illustrates the problems of a knowledge gap and the top-down procedures as well as the challenges that Taiwan faces in becoming a nuclear-free country. This case demonstrates civic society organisations’ efforts to challenge the ‘social–technical divide’ and technical experts’ prior definition of the ‘problems’ and selection of a ‘solution’. Deliberative forums enable the participation of affected communities to shape public discourses, which helps to strengthen public communication, improves citizen consciousness of nuclear waste issues, and attempts to link wider communities and public interests.

Spatial interpolation of gamma dose in radioactive waste storage facility

External radiation measurement for a radioactive waste storage facility in Malaysian Nuclear Agency is a part of Class G License requirement under Atomic Licensing Energy Board (AELB). The objectives of this paper are to obtain the distribution of radiation dose, create dose database and generate dose map in the storage facility. The radiation dose measurement is important to fulfil the radiation protection requirement to ensure the safety of the workers. There are 118 sampling points that had been recorded in the storage facility. The highest and lowest reading for external radiation recorded is 651 microSv/hr and 0.648 microSv/hour respectively. The calculated annual dose shows the highest and lowest reading is 1302 mSv/year and 1.3 mSv/year while the highest and lowest effective dose reading is 260.4 mSv/year and 0.26 mSv/year. The result shows that the ALARA concept along time, distance and shield principles shall be adopted to ensure the dose for the workers is kept below the dose limit regulated by AELB which is 20 mSv/year for radiation workers. This study is important for the improvement of planning and the development of shielding design for the facility.

Радиационный экологический риск для наземной экосистемы в зоне влияния хранилища радиоактивных отходов

Радиационный экологический риск для наземной экосистемы в зоне влияния хранилища радиоактивных отходов

PRELIMINARY DESIGN OF POTENTIAL STORAGE FACILITY FOR LOW AND INTERMEDIATE LEVEL RADIOACTIVE WASTE

An issue concerning the management of radioactive waste (RAW) in the Republic of Croatia continuously rises due to the lack of systematic solutions. In this paper, emphasis is being placed on the storage of RAW, as one of the important phases of RAW management. The current RAW storage facilities are not sufficient and there is a need for a new facility for low and intermediate level radioactive waste (LILW), since such waste accounts for the largest part of RAW. For this reason, a preliminary estimate for a one-storey structure was carried out, a potential storage facility of LILW that would be constructed at the location of 􀀬erkezovac, Trgovska Gora, in the Republic of Croatia, as the currently most prominent location for the realization of the RAW storage facility. The geological characteristics of the site were analysed and, in accordance with the relevant regulations, a static design of the facility was made in the ETABS and SAFE program packages. The construction is a typical reinforced concrete structure, rectangular in plan (10.0 x 30.0 m) with a height of 5.9 m. The selected location meets the given parameters of geological characteristics, while the construction meets the given load and serviceability conditions de􀆤 ned by Eurocode (ultimate limit state and serviceability limit state). However, a more detailed analysis would be necessary if the decision to construct such a storage facility would be made.

Performance Improvement of Liquid Waste Management System for APR1400

The Liquid Waste Management System (LWMS) is a radioactive waste storage and treatment facility equipped in the nuclear power plants to ensure the safe management of radioactive waste generated in the process of operation. New and improved materials and processes are continuously under consideration and development in various countries to reduce waste generation and to minimize costs. To meet the increasing pressure to reduce the release of radioactive into the environment, this study discusses the possible performance improvements of the existing liquid waste management system of APR1400 without additional equipment installation or design changes of the system. This study proposes three possible items for improvement of the Advanced Power Reactor 1400 (APR1400) liquid waste management system which are chemical additions, increasing ion exchange (I.X.) selectivity and optimal operation conditions to reduce the radioactivity concentration in the effluent and solid waste generation. The results of off-site dose calculated by ENDOS-L shows that maximum individual dose is reduced by 12.7% from original values. And the reduction of solid waste generation from the extended replacement period of the membrane is expected to reduce the annual disposal cost by 16.7% from original cost. Improvements do not involve equipment modification so these can be easily applied to currently operating NPPs. It will be helpful to reduce the offsite public dose and operating cost of Nuclear Power Plants(NPPs).

Распространенность, Структура и Особенности Аллерго- и Иммунопатологии Персонала Предприятия по Обращению с Радиоактивными Отходами

Распространенность, Структура и Особенности Аллерго- и Иммунопатологии Персонала Предприятия по Обращению с Радиоактивными Отходами

Risk assessment for human health and terrestrial ecosystem under chronic radioactive pollution near regional radioactive waste storage

An impact of the radioactive waste storage facility at the regional population was assessed under supervision of IAEA. It was made in accordance with the methodology for assessment of doses and risks to human storage using different scenarios of radionuclides releases into the environment. The following scenarios were considered: leakage of fluid, resuspension of dust, fire, flooding. Thy evaluation of radiation doses received and the risks to the human showed that the risk has been acceptable for all scenarios. An approach for an ecological risk assessment for terrestrial ecosystem is presented as five modules: selection of the ecosystem-receptor of radiation effects; determination of reference species of living organisms and their survival indices; the critical load as an absorbed dose rate is calculated from the dependence between the absorbed Sr-90 radiation dose rate and the coefficient of radioactive strontium accumulation in mollusc shells; the critical dose; risk is assessed from a part of the ecosystem territory with increased mollusc loading; uncertainties appeared at each stage of risk assessment are characterized. The risk of exposure to the repository on the ecosystem should be characterized as unacceptable.

X-ray Computed Tomography of Structures in Opalinus Clay from Large Scale to Small Scale after Mechanical Testing

In recent years use of X-ray Computed Tomography (CT) has become more common for geoscientific applications and is used from the µm-scale (e.g. for investigations of micro-fossils or pore scale structures) up to the dm-scale (full drill cores or soil columns). In this paper we present results from CT imaging and mineralogical investigations of an Opalinus Clay core on different scales and different regions of interest, emphasizing especially the 3D evaluation and distribution of cracks and fractures and their impact upon mechanical testing of such material. Enhanced knowledge of the behaviour of the Opalinus Clay as a result of these tests is of great interest, especially since this material is considered for a long term radioactive waste disposal and storage facility in Switzerland. Hence, results are compared regarding the mineral (i.e. phase) contrast resolution, the spatial resolution, and the overall scanning speed. With this extensive interdisciplinary top-down approach it has been possible to characterize the general fracture propagation in comparison to mineralogical and textural features of the Opalinus Clay. Additionally, and to the best of our knowledge, a so called mylonitic zone has been observed for the first time in an experimentally deformed Opalinus sample. The multi-scale results are in good accordance with data from naturally deformed Opalinus Clay samples, which allows systematic analysis under controlled laboratory conditions. Accompanying 3D imaging greatly enhances the capability of data interpretation and assessment of such material.

X-ray computed tomography investigation of structures in Opalinus Clay from large-scale to small-scale after mechanical testing

Abstract. In the past years X-ray computed tomography (CT) has became more and more common for geoscientific applications and is used from the µm-scale (e.g. for investigations of microfossils or pore-scale structures) up to the dm-scale (full drill cores or soil columns). In this paper we present results from CT imaging and mineralogical investigations of an Opalinus Clay core on different scales and different regions of interest, emphasizing especially the 3-D evaluation and distribution of cracks and their impact on mechanical testing of such material. Enhanced knowledge of the testing behaviour of the Opalinus Clay is of great interest, especially since this material is considered for a long-term radioactive waste disposal and storage facility in Switzerland. Hence, results are compared regarding the mineral (i.e. phase) contrast resolution, the spatial resolution, and the overall scanning speed.With this extensive interdisciplinary scale-down approach it has been possible to characterize the general fracture propagation in comparison to mineralogical and textural features of the Opalinus Clay. Additionally, and as far as we know, a so-called mylonitic zone, located at an intersect of two main fractures, has been observed for the first time for an experimentally deformed Opalinus sample. The multi-scale results are in good accordance to data from naturally deformed Opalinus Clay samples, which enables us to perform systematical research under controlled laboratory conditions. Accompanying 3-D imaging greatly enhances the capability of data interpretation and assessment of such a material.

Application of zonality conceptual model of chronic effects of ionizing radiation for studying the behavior of Sr-90 in terrestrial ecosystems

Behavior of Sr-90 radionuclide in the system of «soil-plants-mollusc shells» was investigated on the example of biotope of regional radioactive waste storage facility. The purpose of the study was to examine the possibility of applying the conceptual model of zonality of chronic effects of ionizing radiation in natural populations in the investigation of behavior of radioactive strontium in terrestrial ecosystems and to identify radioecological zones of biological effects of chronic exposure to ionizing radiation of the mollusc population based on of the bio-geochemical regularities of technogenic migration of Sr-90 within the «soil-plants-mollusc shells» system. The study was conducted on the experimental site which represented the biotope of the regional radioactive waste storage facility. Analysis of samples of soil, plant (Urtica dioica) and terrestrial molluscs was implemented by the method of radiochemical separation followed with measuring the activity of the radionuclide using scintillation spectrometer «BETA-01C». Annual exposures to external beta-radiation received by tissues of molluscs irradiated by Sr-90 and its daughter radionuclide Y-90 contained in the shells were calculated using Levinger and Marinelli formula.It was discovered that dose rates of irradiation of molluscs Bradybaena Fruticicola fruticum are within 0.03–1.60 Gy/year. Structuring of experimental data was implemented based on the obtained data on the specific activity of Sr-90 in the system under study in accordance with model by G.G.Polikarpov. Three ecological zones were identified on the experimental site with regular variation of specific activity of Sr-90 in mollusс shells. In the zone of physiological masking concentration of radionuclide in mollusc shells can be by one order of magnitude and even more higher than in the plant. In the zone of ecological masking and the zone of pronounced environmental effects specific activities of the radionuclide are reduced as compared to its concentration in plants by 8 and 40 times, respectively (no decrease of specific activities of the radionuclide in the plant is regisrered). The implemented studies allow formulating the conclusion on the possibility of adaptation of indicators of Sr-90 migration in terrestrial ecosystems.

Thermal and physical properties of reconsolidated crushed rock salt as a function of porosity and temperature

Crushed salt can be used as backfill to bury and conduct heat away from radioactive waste in salt repositories. As the crushed salt compacts during reconsolidation, its thermal, mechanical and hydrologic properties will change in a manner related to the porosity. Measurements of crushed salt thermal properties are conducted to evaluate such relationships. A simple mixture theory model is presented to predict thermal conductivity of consolidating salt in repository conditions. Experimental work was completed to evaluate the model by measuring thermal conductivity, thermal diffusivity and specific heat of crushed salt as a function of porosity and temperature. Sample porosity ranged from 0 to 46 %, and measurements were made at ambient pressure, from room temperature to 300 °C. These are the temperature conditions expected in a radioactive waste storage facility. Crushed salt thermal conductivity decreases with increasing porosity and temperature. Thermal diffusivity showed little porosity dependence but decreased with increasing temperature. Specific heat also shows little porosity dependence but increases with increasing temperature. Fracture porosity in deformed bedded salt cores appears to reduce thermal conductivity more dramatically than inter- and intra-granular porosity in consolidated salt. A long-term effort to dry crushed salt at high temperatures resulted in a 0.48 weight-percent loss of water that had resided at grain boundaries and in intra-granular fluid inclusions. While this loss does not significantly affect thermal properties, the release of this water volume could impact the mechanical response of the reconsolidating salt and host rock.

Radon exposure at a radioactive waste storage facility

The Waste Management Department of Nuclear and Energy Research Institute (IPEN) is responsible for the safety management of the waste generated at all internal research centers and that of other waste producers such as industry, medical facilities, and universities in Brazil. These waste materials, after treatment, are placed in an interim storage facility. Among them are 226Ra needles used in radiotherapy, siliceous cake arising from conversion processes, and several other classes of waste from the nuclear fuel cycle, which contain Ra-226 producing 222Rn gas daughter. In order to estimate the effective dose for workers due to radon inhalation, the radon concentration at the storage facility has been assessed within this study. Radon measurements have been carried out through the passive method with solid-state nuclear track detectors (CR-39) over a period of nine months, changing detectors every month in order to determine the long-term average levels of indoor radon concentrations. The radon concentration results, covering the period from June 2012 to March 2013, varied from 0.55 ± 0.05 to 5.19 ± 0.45 kBq m−3. The effective dose due to 222Rn inhalation was further assessed following ICRP Publication 65.

The environmental impact assessment process for nuclear facilities: A review of the Lithuanian practice and experience

The only one nuclear power plant (NPP) in the Republic of Lithuania – Ignalina NPP has been shutdown and entered the phase of decommissioning. Decommissioning activities, along with dismantling works, include construction and operation of a new spent nuclear fuel and radioactive waste management, storage and disposal facilities. The new NPP in Lithuania, if such would be constructed, are to be located adjacently to the existing plant. Current and future planned nuclear activities in Lithuania are concentrated in a single location, in the northeast of the country near the state borders with the Republic of Latvia and the Republic of Belarus. Number of different projects and participants involved, necessity to control and limit overall impact on the environment require for planning and coordination of activities and impacts, including consideration and updating of outcomes from the previous environmental impact assessment (EIA) studies. Regulatory review and coordination of EIA documents also demands substantial time resources, impacts schedule of activities and therefore must be properly planned and managed. The paper describes approach and progress in EIA for nuclear activities in Lithuania and examines experience gained in preparation, review and coordination of EIA studies. Emphasis is placed on approach that has been used to deal with cumulative radiological impact because acceptability of this impact is one of primary goal in demonstration of acceptability of the newly planned nuclear activities.

Intelligent Radioactive Waste Management Platform for Radioactive Waste Storage Facilities

Radioactive waste management is now a much discussed public issue, especially since the Taiwanese government announced that three operating nuclear power plants will be decommissioned on schedule. Safe, efficient, reliable, and sustainable solutions to the management of radioactive wastes are critical to the feasibility of the nuclear decommissioning project. Because of the lack of system integration within radioactive waste storage facilities, most of the radioactive waste information systems remain inconsistent. Therefore, the establishment of an intelligent integrated system that provides active assistance in tracing the processes of radioactive wastes is urgent.This study is based on the technology of radio frequency identification for detection of radioactive waste locations. An automatic identification mechanism can monitor the status of storage and instantly notify the relevant parties. Meanwhile, this platform also employs the software agent as the infrastructure to construct the integrated information system architecture; the software agent has been widely accepted as an effective method to integrate heterogeneous systems of the new paradigm. The overall framework will help enhance the monitoring performance for radioactive waste.

On leakage from the near-surface radioactive waste storage facility

Maisiagala RADON type radioactive waste storage facility was commissioned in 1963 in a marshy, ecologically sensitive locality, where soluble radionuclides easily can penetrate and migrate with groundwater. To assure the requirements of radiation safety, the analysis of radionuclide leakage from the radioactive waste storage facility is performed continuously. 3H (tritium, T1/2=12.33 years) is of greatest interest in the storage facility reservoir or its surroundings. Liquid scintillation counting (LSC) involving ultra-low level device Quantulus (Wallac) was utilized for quantitative determination of tritium. Elevated 3H concentration (reached 23900 Bq l-1) is observed continuously in the borehole, which is nearest to the radioactive waste reservoir. The average prevailing groundwater flow direction is close to the northern direction. This is the direction of waterlogged lowland, the head of the river, where radionuclides can penetrate. 3H concentration in the borehole located 12 m further in the prevailing groundwater flow direction, varies from minimum detectable values to 7500 Bq l-1. MOC3D software was used for modelling 3H transport in groundwater. For field measurements a portable gamma-spectrometer Inspector-2000 (Canberra) with 20% relative efficiency HPGe detector (GC2018) was used. The measurements in-situ revealed both qualitative and quantitative variation of gamma-ray intensity at the facility’s territory and outside.The remaining contamination by 226Ra was confirmed at the spot at the distance of ~20 m from the radioactive waste reservoir, 226Ra concentration at the spot reached 106 Bq kg-1 in 2004. 137Cs concentration in soil does not exceed that in Lithuanian soils after Chernobyl NPP accident. 3H concentration in soil moisture, both on the territory of facility and outside, increases with depth and reached 187±10 Bq l-1. 3H concentration in lupine (Lupinus polyphyllus) reached 150±9 Bq l-1. It exceeds 3H concentration in grass outside the facility territory by 20-30 times. The fact that elevated 3H concentration was found not only in groundwater of boreholes on the territory of the storage facility, but in soil moisture and vegetation samples shows that radionuclide leakage from the reservoir occurs and the possibility of leakage can increase over time. The storage facility requires continuous monitoring and management strategy in the nearest future.

Environmental safety aspects of the new solid radioactive waste management and storage facility at the Ignalina Nuclear Power Plant

Abstract New solid radioactive waste management and interim storage facilities will be constructed for the Ignalina Nuclear Power Plant to support ongoing decommissioning activities, including removal and treatment of operational waste from the existing storage buildings. The paper presents approach and methods that have been used to assess radiological impacts to the general public potentially arising under normal operation and accident conditions and to demonstrate compliance with regulations in force. The assessment of impacts from normal operation includes evaluation of exposure arising from release of airborne radioactive material and from facilities and packages containing radioactive material. In addition, radiological impacts from other nearby operating and planned nuclear facilities are taken into consideration. The assessment of impacts under accident conditions includes evaluation of exposure arising from the selected design and beyond design basis accidents.

Progress of radioactive waste management in Lithuania

The only one nuclear power plant in the Republic of Lithuania – Ignalina Nuclear Power Plant contains two RBMK-1500 water-cooled graphite-moderated channel-type power reactors. The first and the second reactors were shut down by the end of 2004 and by the end of 2009, respectively. During operation, the power plant has accumulated large quantities of radioactive waste, including spent nuclear fuel. As a result of the decision to implement immediate dismantling strategy for the decommissioning of the Ignalina Nuclear Power Plant, quantities of radioactive waste to be managed within the next 10–20 years will increase significantly. Therefore, a reliable and effective management of radioactive waste has become a key to the Lithuania’s nuclear programme. The paper describes key aspects of the Lithuania’s national policy and strategy in radioactive waste management, legislative and financing systems. The main emphasis is given to the progress in radioactive waste management practices. Projects on construction of new solid radioactive waste management and storage facility, disposal facilities for very low level short-lived radioactive waste and for low and intermediate level short-lived radioactive waste, new free release measurement facility, new spent nuclear fuel interim storage facility are in progress. The set of currently implemented and planned actions shall bring management, interim storage and disposal of radioactive waste in Lithuania in compliance with the radioactive waste management principles of International Atomic Energy Agency and with the good practices in force in European Union Member States.

Free energy of formation for green rust sodium sulphate (NaFe II6Fe III3(OH) 18(SO 4) 2(s))

In a recent study, sulphate-bearing green rust ( GR SO 4 ) was shown to incorporate Na + in its structure (NaFe II 6Fe III 3(OH) 18(SO 4) 2(s); GR Na, SO 4 ). The compound was synthesised by aerial oxidation of Fe(OH) 2(s) in the presence of NaOH. This paper reports on its free energy of formation ( Δ G f 0 ) . Freshly synthesised GR Na, SO 4 was titrated with 0.5 M H 2SO 4 in an inert atmosphere at 25 °C, producing dissolved Fe 2+ and magnetite or goethite. Solution concentrations, PHREEQC and the MINTEQ database were used to calculate reaction constants for the reactions: 2 NaFe II 6 Fe III 3 ( OH ) 18 ( SO 4 ) 2 ( s ) + 12 H + ( aq ) ⇆ 9 Fe 2 + ( aq ) + 2 Na + ( aq ) + 4 SO 4 2 - ( aq ) + 3 Fe II Fe III 2 O 4 ( s ) + 24 H 2 O ( l ) , K = 10 54.5 ± 3.0 and NaFe II 6 Fe III 3 ( OH ) 18 ( SO 4 ) 2 ( s ) + 9 H ( aq ) + ⇆ 6 Fe 2 + ( aq ) + Na + ( aq ) + 2 SO 4 2 - ( aq ) + 3 α - FeOOH ( s ) + 12 H 2 O ( l ) , K = 10 42.5 ± 3.7 . From the determined equilibrium constants and published Δ G f 0 values for the other compounds, we derived Δ G f 0 = −6366 ± 18 kJ/mol for anhydrous GR Na, SO 4 . The solubility product at 25 °C and atmospheric pressure is K = 10 −210.5±3.2. It is not yet known if the extent of Na + incorporation in GR SO 4 depends on formation pathway; it cannot be excluded that both Na-free GR SO 4 and GR Na, SO 4 exist. If so, uncertainty in Δ G f 0 determined from acid titration is such that the E H–pH stability fields of the two phases are statistically indistinguishable for Na + concentrations as low as ∼30 μM (2 SD level; 0.036 M SO 4 2− concentration). In sea water, where Na + and SO 4 2− concentrations are high, but soluble Fe 2+ is low, GR is expected to form where local conditions increase concentration gradients, such as for corrosion of metallic iron and steel. Another example of an environment that would provide GR Na, SO 4 -favourable conditions is a degrading concrete and steel radioactive waste storage facility, where groundwater is saline. Green rust is a well-known sink for redox-active trace components, making it a compound that should be considered in risk assessment modelling of groundwater quality. Phase stability is critical in such simulations.

Study for Regional Cooperation on Radioactive Waste Management in Northeast Asia

ABSTRACT Anti-nuclear sentiment has been dramatically changed in the 2000s, because of energy prices hike and climate change conventions. Some experts assert that this positive and affirmative reaction toward nuclear generation could lead to 'nuclear renaissance' in the near future. Korea, Japan, China located in Northeast Asia has not been affected by nuclear evasion policy (keeping away from nuclear policy) from European countries, their energy policies are still kept focused on nuclear energy. Each country faces lack of storage facility for radioactive waste. This paper explores possibility of building an international radioactive waste disposal and storage facility in the Northeast Asian region. It is considered that Northeast Asian region as one of candidates for international radioactive waste disposal and storage facility and investigated each country's situation and proposed recommendation to make the facility in this region possible. Through this energy cooperation idea, each country in Northeast Asian region can solves radioactive waste disposal and storage problem and strengthens energy security by utilization of more nuclear generation. Northeast Asian countries need to discuss the possibility of the construction of international facilities by increasing mutual understanding among nations. And, in order to prepare for changes of economic and social situation and to promote interests among the international communities, South Korea needs to undertake further researches and develop a cooperative strategy for radioactive waste management in this region.