Projects

National

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