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| RADLON – Vplyv radiačnej záťaže na sklovláknitú izoláciu z hľadiska recirkulácie chladiva v havarijných podmienkach jadrových elektrární s tlakovodnými reaktormi | |
| Influence of radiation load on fiberglass insulation in terms of refrigerant recirculation in emergency conditions of nuclear power plants with pressurized water reactors | |
| Program: | SRDA |
| Project leader: | prof. Ing. Liška Marek, DrSc., Dr.h.c. |
| Annotation: | The aim of the Project is to extend the methodology of verifying the functional capability of emergency core cooling systems in case of loss-of-coolant accidents as well as that of cooling systems intended for severe acc idents from the standpoint of impacts of long-term exposure of thermal insulation to radiation at elevated temperatures and in such a way to actively contribute to increasing the operating safety of nuclear power plants. Within the Project, samples of thermal insulation exposed to accelerated heat and radiation ageing will be investigated. The radiation doses are anticipated to be at the level of a 40-year operation at a dose rate of 10 Gy/h on the primary circuit of a WWER 440 V213 type NPP. Samples treated in such a way will be investigated from the standpoint of changes in their physico-mechanical properties as well as from the standpoint of their chemical resistance to corrosive effects of emergency reactor coolant. However, preparation of the samples by accelerated heat and radiation ageing i s extremely both time-consuming and costly. For instance, to obtain a sufficient radiation dose at a level simulating a 40-year operation (approximately 3500 kGy), irradiation period is needed equal to approximately 1650 h of net irradiation time with an average irradiation dose rate of 2 kGy/h. Irradiation is to be performed at an elevated temperature of 300°C which means that it will have to be performed in a thermal box. That is why it is necessary to develop a procedure for simulation of irradiation effects in order to obtain a sufficient number of samples for integrated testing. A feasible solution seems to be thermo-mechanical loading of the samples since, based on the knowledge obtained so far, thermal insulation fibres under the effect of irradiation at elevated temperature lose their mechanical elasticity and become brittle. In addition, their chemical resistance to corrosion effects of the coolant solution changes. |
| Duration: | 1.7.2023 – 30.6.2027 |
| Luminofory s nulovým teplotným zhášaním luminiscencie pre aplikácie v pc-WLED s NUV excitáciou | |
| Zero-thermal-quenching phosphors for NUV converted pc-WLEDs application | |
| Program: | VEGA |
| Project leader: | prof. Ing. Galusek Dušan, DrSc. |
| Annotation: | The project is focused on research and development of new type phosphors with zero thermal quenching (TQ) behaviour, for potential application in light sources based on conversion of excitation light in NUV spectral range (produced by LED chip) to visible light, such as high power HB LEDs (high brightness LED) or laser lighting.Phosphors will be prepared as powders/nano-powders and as PiG (Phosphor in Glass) composites. The effect of activator and co-dopant concentration on PL emission intensity produced by phosphor under NUV excitation will be investigated. Photoluminescence properties of phosphors containing rare-earth and transition metal ions will be studied in detail with special attention on near-zero/zero TQ behaviour of phosphors up to 250°C. The attention will be paid to study of relations between luminescent properties of materials and their structure and morphology. |
| Duration: | 1.1.2022 – 31.12.2024 |