4. Ionization Microclimate C:\Users\21536\AppData\Local\Temp\7zOCBEF4013\interreg_Rakousko_Ceska_Republika_RGB.jpg https://www.email.cz/download/k/vPwBms0jPnQoTvgo0jFvvGwDhdh9Jlfl9rKdiuyzDRyHOOMId1HvJLvOPRBH2skc4uZ VKBw/image001.png Fachhochschulen Oberösterreich Ionization Microclimate •Ionization microclimate is a component of indoor environment formed by flows of ionizing radiation produced by radioactive substances of natural or artificial sources, which act on the individual and form one's overall condition. • •The basic physical quantity of ionization is the activity (Ak) of a given amount of radionuclide expressing the proportion of the mean number of radioactive changes and the time interval. The unit of activity is one decay per second or Becquerel (Bq). • •The source of ionizing radiation may be radioactive substances penetrating into the interior from the external environment, or substances occurring inside the building due to anthropogenic activities and the release of building materials and technological equipment containing radioactive material. C:\Users\21536\AppData\Local\Temp\7zOCBEF4013\interreg_Rakousko_Ceska_Republika_RGB.jpg https://www.email.cz/download/k/vPwBms0jPnQoTvgo0jFvvGwDhdh9Jlfl9rKdiuyzDRyHOOMId1HvJLvOPRBH2skc4uZ VKBw/image001.png Fachhochschulen Oberösterreich Ionization Microclimate •Radioactivity is the transformation of the core of an element into the core of another element, while releasing large amounts of energy in the form of invisible radiation (so-called radioactive radiation) that is dangerous to humans. There is natural and artificial radioactivity. • •Radionuclide is a nuclide with an unstable nucleus whose atoms are subject to radioactive transformation together with the emission of ionizing radiation. • •Half-life is the time taken for half the radionuclide's atoms to decay. The half-life is constant for the isotope of the given element. The half-life has values from a fraction of a second to millions of years. C:\Users\21536\AppData\Local\Temp\7zOCBEF4013\interreg_Rakousko_Ceska_Republika_RGB.jpg https://www.email.cz/download/k/vPwBms0jPnQoTvgo0jFvvGwDhdh9Jlfl9rKdiuyzDRyHOOMId1HvJLvOPRBH2skc4uZ VKBw/image001.png Fachhochschulen Oberösterreich Optimization of Ionizing Radiation •Optimization of ionizing radiation can be ensured either by intervention into the source of radioactive material, or interference into the transmission field of ionizing radiation. •Intervention into the source can be performed by: •Selecting a suitable building site (locality) •limiting or preventing the penetration of radon into the building (antiradon measures) •Choosing suitable building materials (certified materials and products) •Interferences into the transmission involves: •Restricting the spread of radioactive substances in the building •Ventilation and air filtration •Surface deposition, i.e. sedimentation of radioactive substances •Electrostatic deposition C:\Users\21536\AppData\Local\Temp\7zOCBEF4013\interreg_Rakousko_Ceska_Republika_RGB.jpg https://www.email.cz/download/k/vPwBms0jPnQoTvgo0jFvvGwDhdh9Jlfl9rKdiuyzDRyHOOMId1HvJLvOPRBH2skc4uZ VKBw/image001.png Fachhochschulen Oberösterreich Optimization of Ionizing Radiation •The limitation of the spread of radioactive substances in the building can be achieved by design-layout modifications of the building such as dividing vertical shafts into smaller sections, appropriately transferring sources of radioactive material in the building, or applying differential ventilation. •The spread of ionizing radiation is a problem especially in multi-storey buildings, when the radioactive material is propagated by thermal buoyancy. •Continuous stairs along the height of the building without interruption can be a source of intense spread of radioactive gases throughout the building. C:\Users\21536\AppData\Local\Temp\7zOCBEF4013\interreg_Rakousko_Ceska_Republika_RGB.jpg https://www.email.cz/download/k/vPwBms0jPnQoTvgo0jFvvGwDhdh9Jlfl9rKdiuyzDRyHOOMId1HvJLvOPRBH2skc4uZ VKBw/image001.png Fachhochschulen Oberösterreich Optimization of Ionizing Radiation •In addition to ensuring adequate air exchange, it is advisable to design pressure zones between spaces according to the degree of their contamination (contamination). • •The largest negative pressure is chosen for areas with the highest contamination. Air recirculation is not included in such areas. • •Reducing the dose of fresh air in order to reduce the energy performance of a building can result in an increased concentration of radioactive substances in the building. C:\Users\21536\AppData\Local\Temp\7zOCBEF4013\interreg_Rakousko_Ceska_Republika_RGB.jpg https://www.email.cz/download/k/vPwBms0jPnQoTvgo0jFvvGwDhdh9Jlfl9rKdiuyzDRyHOOMId1HvJLvOPRBH2skc4uZ VKBw/image001.png Fachhochschulen Oberösterreich Optimization of Ionizing Radiation •Filters can reduce the spread of radioactive substances bound to some kind of aerosol. There are two types of filters - cassette or electrostatic: •Cassette filters are boxes with a filter cartridge. Filter cartridges are not washable, but they are replaced with new ones (low acquisition costs, but higher operating costs) •Electrostatic filters do not increase overall system pressure over time (like other filters). Captured particles can be washed with water (high cost of ownership, cheap operation). •Electrostatic deposition operates on the principle of artificially created electrostatic field. Electrically charged particles settle on electrodes of opposite polarities. C:\Users\21536\AppData\Local\Temp\7zOCBEF4013\interreg_Rakousko_Ceska_Republika_RGB.jpg https://www.email.cz/download/k/vPwBms0jPnQoTvgo0jFvvGwDhdh9Jlfl9rKdiuyzDRyHOOMId1HvJLvOPRBH2skc4uZ VKBw/image001.png Fachhochschulen Oberösterreich