Radiation protection and environment

Special components and systems were provided at the INPP that ensured protection of the plant and its environment during normal operation and in emergencies. The following systems are used for radiation protection and monitoring:

• A highly reliable automatic control and protection system
• Reactor emergency core cooling system
• Accident confinement system
• Fuel cladding integrity monitoring system
• Radioactive gas-aerosol waste discharge cleaning specialized plant
• Liquid RW removal, processing and storage system
• Automatic plant radiation protection monitoring system
• Automatic monitoring system of gas-aerosol and liquid waste
• Automatic system of environment radiation monitoring
• Means and methods of environment radiation monitoring

 A monitoring system has been developed expressly for the RBMK-1500 reactors that enabled to detect with state-of-the-art methods fuel assemblies whose integrity has been damaged and to instantaneously monitor the radiation state of the reactor core.

The automatic plant radiation protection monitoring system comprises radiation monitoring instruments covering all the elements and systems of the facility, which makes it possible to maintain safe radiation levels while carrying out all kinds of operations, such as removal of fuel assemblies whose integrity was damaged, deactivation, replacement or repairs of fuel channels, etc.

To reduce the emissions of inert radioactive gases, a two-stage purification process is used at the INPP, with treated gas and aerosol waste released to the environment through a 150-meter-high ventilation stack.

A delay chamber is used for stage one, where concentration decreases with the level of radiation. The concentration reduction device used for stage two cleans inert gases and lowers their concentration by the dynamic sorption method. Special filters are used to absorb radioactive aerosols in the gaseous effluent to prevent it from entering the atmosphere. A circular system of water supply is used at the NPP. Equipment of automated monitoring of radiation protection has been installed at the nuclear power facility.

The radiation levels of gases, aerosols and liquid RW released to the environment is continuously being monitored by means of automatic equipment of the radiation control system. The NPP’s environment radiation monitoring service is equipped with state-of-the-art instrumentation for analysing radionuclides in the environment. The INPP laboratory has spectrometers that enable to objectively assess the radioactivity of the environment.