Šiame darbe eksperimentiniais ir modeliavimo metodais buvo nagrinėjami skirtingose hidrogeologinėse sąlygose esančių branduolinių objektų aikštelių aeracijos zonos gruntuose vystantys drėgmės (ir priemaišų) pernašos procesai. Aeracijos zonos profiliai buvo palyginti atlikus eksperimentinius tyrimus ir apibendrinus duomenis apie gruntų hidraulines savybes, drėgnį ir izotopinę sudėtį. Krituliuose ir aeracijos zonos grunto profilių drėgmėje buvo nustatyti globaliai paplitusio radionuklido tričio bei vandens molekulės izotopinių traserių pasiskirstymo ypatumai. Nustatyta, kad krituliuose pasireiškiančios stabiliųjų izotopų sezoninės variacijos aeracijos zonoje ir ypač gruntiniame vandenyje beveik išnyksta, tačiau išlieka nežymūs sezoninių smailių pėdsakai, kurie Maišiagalos aikštelėje yra šiek tiek kontrastiškesni nei Stabatiškės aikštelėje, kadangi Maišiagalos aikštelėje drėgmės tranzito aeracijos zonoje laikas trumpesnis. Priėmus hipotetines žemės paviršiaus užtvindymo sąlygas esant žemam, vidutiniškam ir aukštam slėgiui, momentiniam ir pastoviam priemaišų įvedimui, palyginimui buvo išnagrinėti šeši scenarijai. Sudarytas tričio pernašos aeracijos zonoje modelis parodė, kad paros įvesties parametrų suvidurkinimas atskiram mėnesiui gali riboti tričio koncentracijos aeracijos zonos profilyje ir vandens balanso elementų pasiskirstymo atkūrimą. / Two nuclear waste disposal sites (Maišiagala radioactive waste storage facility site and Stabatiškė near surface repository site) were compared in terms of the contaminant movement through the unsaturated zone. Extensive data sets of the hydraulic properties, water content and isotope composition have been collected and summarized. Distribution features of globally widespread radionuclide tritium and the water molecule tracer isotopes in precipitation, unsaturated zone soil moisture profiles and groundwater were determined. Stable isotopes seasonal variation occurring in precipitation almost disappears in the unsaturated zone soil moisture and especially in shallow groundwater, but in both sites slight seasonal peak traces remain, which at the Maišiagala site are a bit more contrasting in comparison with the Stabatiškė site. Both sites were modelled by using unsaturated flow and transport models. Six scenarios have been developed to simulate the water and solute movement under low, moderate, and high water input, and instantaneous and continuous solute input conditions. In order to validate the representativeness of the hydraulic parameters, the model has been used to estimate the tritium distribution in the unsaturated zone, which properly represents the dynamics of the unsaturated zone. The uniformity of the daily input in each month should be kept in mind in the evaluation of the smooth changes of the tritium profile and water budget elements.

No description available.

This study investigates the runoff process and groundwater behavior in a subarctic watershed called Wolf Creek Research Basin, in Whitehorse, Yukon Territory, Canada. This basin is underlain by discontinuous permafrost that is typical of high latitude watersheds. Goundwater supports the stream flow year round and dominated the hydrology in most of the study period as baseflow. The baseflow was concentrated in dissolved ions. However, the baseflow was diluted during the melt season in May and June of 2012. Multiple chemical and isotopic tracers were used to develop a robust three-component (groundwater, soilwater and precipitation) mixing model for runoff generation. The concentrations of weathering ions decreased with the increased discharge during the melt. Soilwater was responsible for about 60% of the streamwater on the hydrograph in the melt season. The infiltration of the meltwater from the snowpack and the thawed water from the seasonal frost to the baseflow existed. The tritium concentrations indicated that there was fast moving hydrogeological system within the basin. The baseflow was also characterized as relatively enriched in both 13C and 14C, and concentrated in DIC. DIC was the major loss of carbon in Wolf Creek Research Basin.Le pergélisol est grandement sous-jacent dans les bassins-versants à haute latitude. Cette étude examine le processus de ruissellement et le comportement des eaux souterraines dans un bassin-versant subarctique de Wolf Creek, à Whitehorse, territoire du Yukon au Canada. Les eaux souterraines soutenaient l’écoulement fluvial et dominaient l’hydrographe comme débit de base durant la majorité de la période d’étude. Le débit de base était concentré d’ions dissipés. Par contre, le débit de base était dilué durant la saison des fontes au mois de mai et juin 2012. Plusieurs traceurs chimiques et isotopiques étaient utilisé afin de développer un modèle de trois composants (eau souterraine, eau interstitielle de sol et précipitation) de ruissellement. Les concentrations de la déségrégation des ions diminuaient avec l’augmentation du débit durant la fonte. Les eaux interstitielles des sols étaient responsables de 60% de l’eau de ruisseau sur l’hydrographe durant la saison de fontes. L’infiltration de l’eau de fonte du manteau neigeux et l’eau du gel du débit de base existaient. Les concentrations de tritium indiquent qu’il y avait un système hydrogéologique qui se déplaçait à grande vitesse dans les limites du bassin. Le débit de base était aussi caractérisé comme étant enrichi en 13C et 14C, avec des concentrations en carbone inorganique dissous.

A dynamic model was developed for the distillation mechanism of the Darlington Tritium Removal Facility. The model was created using the commercial software package MATLAB/Simulink. The goal was to use such a model to predict the system behaviour for use in control analysis. The distillation system was first divided into individual components including columns, condensers, controllers, heaters and the hydraulic network. Flow streams were then developed to transfer enthalpy, pressure and mass flow rate between the components. The model was able to perform various plant transients for validation and analysis purposes. A comparison of the different controllers was made with the introduction of various disturbances to the system. Also, the effect of the system disturbances when isolated from the transients was studied using the same controllers. Studying different plant transients and disturbances under each controller enabled a comparative analysis.

A dynamic model was developed for the distillation mechanism of the Darlington Tritium Removal Facility. The model was created using the commercial software package MATLAB/Simulink. The goal was to use such a model to predict the system behaviour for use in control analysis. The distillation system was first divided into individual components including columns, condensers, controllers, heaters and the hydraulic network. Flow streams were then developed to transfer enthalpy, pressure and mass flow rate between the components. The model was able to perform various plant transients for validation and analysis purposes. A comparison of the different controllers was made with the introduction of various disturbances to the system. Also, the effect of the system disturbances when isolated from the transients was studied using the same controllers. Studying different plant transients and disturbances under each controller enabled a comparative analysis.

Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2009. / Committee Chair: van Rooijen, Wilfred; Committee Member: Hertel, Nolan; Committee Member: Stacey, Weston

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The main goal of this Thesis was to measure tritium activity in the Vltava River and in the vicinity of Temelín Nuclear Power Plant (hereinafter referred to as JETE) with the following objectives: Possibility to use the outlet of waste water damping unit (hereinafter referred to as VTOOV) as a control alerting system for nonstandard events in JETE, furthermore, monitoring of possible correlations between volume activity of tritium measured in VTOOV and activity above the limit value of the first quality class in selected sections of the Vltava River as well as comparison of the measured values with the results of other authors, and, finally, assessment of the relevance of the water quality estimated by the volume activity of tritium to the water quality according to other ingredients, i.e., stable isotopes of some metals and risk elements as well as general physical and chemical indicators. Theoretical part of the Thesis deals with radioactivity in general, activity of tritium, with regard to operation of nuclear plants, over the world and, especially, in the Czech Republic. The actual work consisted of collection of samples at predetermined places, preparation of these samples for measurement and measurement of tritium activity using scintillation spectrometer with liquid scintillator. Furthermore, basic chemical and physical properties of water, concentration of selected elements and also some anions were determined. The collected data were used for classification of waters from individual collection places into quality classes according to ČSN 75 7221. In all analyzed cases no activities were found which exceeded the limit values of liquid outlets from Temelín Nuclear Power Plant, given by regulations issued on waters by the District Health Office in Ceske Budejovice according to §8 of Act No. 138/73 Coll., in compliance with SÚJB requirements. This Thesis could be beneficial for possible utilization of VTOOV as a control alerting system for nonstandard events in JETE and also for assessment of impact of wastewaters from JETE on waters of the Vltava River.

The State Office for Nuclear Safety (SONS) and the National Radiation Protection Institute (NRPI) are involved in independent monitoring of surrounding areas of nuclear power plants (NPPs), in accordance with the Czech legislative requirements (Decree No. 319/2002 Coll. on radiation monitoring network (RMS), as amended by Decree No. 27/2006 Coll.). The monitoring includes surveillance of environmental samples, in which radionuclides can be detected in case of emergency event, i.e. radioactivity release from the NPP. Another part of the monitoring is measurement of photon dose equivalent, continuously in the air (early detection network - SVZ) or using thermoluminescent dosimeters (TLD) placed in SONS monitoring points in the NPP vicinity. Environmental sampling and evaluation of photon dose equivalent in the air is carried out in regular intervals. The 137Cs and 131I activity is measured by gamaspectrometry method used with Gamat evaluation program, according to SONS internal procedure (VDMI). Tritium activity in surface water is measured by liquid scintillation spectrometer Beta TriCarb made by Canberra Packard Company, according to methodology CSN ISO 9698 (757635). Evaluation of dose equivalent rate is carried out continuously by LB 6360 proportional probe and LB 6500-3 Geiger-Muller tube located in RC Building in Ceske Budejovice. TLD evaluation is carried out by NRPI laboratory in Prague and the results are sent to SONS RC Ceske Budejovice. Goal of this work is to provide a set of results of the independent monitoring in surrounding areas of Temelin NPP (ETE) carried out between 1999 and 2009, by determination of volume, mass or surface activity of environmental samples (137Cs and 131I) and spot samples of water (3H) taken from SONS monitoring points near ETE . The set of such results should provide a baseline reference values for normal (pre-accident) situations. Additionally, based on the long term of the ETE surrounding surveillance, it can be shown that the ETE operation represents no threat to the health of the critical population group, and that the radiation situation in the ETE surrounding is stable. It can be also shown that the ETE operator meets requirements and conditions of authorized limits for discharging radionuclides into the environment. Procedures and method of independent environmental monitoring in the ETE surrounding during emergency events can be proposed on the basis of many years of experience with proven methodologies, experience with sampling locations, staffing and organization of measurement.