The analysis of water sampling and special sewage systems at the Rivne NPP.
Students Name: Boriichuk Ihor
Qualification Level: magister
Speciality: Heat and Power Engineering
Institute: Institute of Power Engineering and Control Systems
Mode of Study: part
Academic Year: 2022-2023 н.р.
Language of Defence: ukrainian
Abstract: Boriychuk I.P., Lys S.S. (head). The analysis of water sampling and special sewage systems at the Rivne NPP. Master’s thesis. - Lviv Polytechnic National University, Lviv, 2022. The sampling system of the coolant of the first and second circuits is designed for chemical and radiochemical control of the water regime of the first and second circuits and the operation of auxiliary systems of the reactor compartment. The criterion for designing the system is to ensure the receipt of a representative sample for the necessary laboratory analysis of the controlled environment. The system provides devices for throttling and lowering the coolant temperature to 40-50oC (313-323 K). The system operates in all modes of normal operation of the unit, including start, stop, transient modes, and in case of violations of normal operation, not related to the dissolution of the primary circuit. The special sewerage system is designed to ensure closed self-flowing collection of unorganized primary circuits with radioactivity up to 10-2 Ki / l from the reactor compartment, decontamination, as well as regeneration and wash water to prevent uncontrolled release of radioactive water into the environment and further into the environment. special corps. The system meets the following requirements: • elements of the system exclude communication of premises by air through pipelines; • the design of the system prevents the coolant of the primary circuit from leaving the sealed shell in case of accidents related to the sealing of the primary circuit and increasing the pressure in the sealed shell over 0.3 kgf / cm2 (0.029 MPa); • the system provides self-flowing collection of decontaminating aqueous solutions after external decontamination of equipment and premises; • the system provides the supply of special sewage water for treatment at SVO-3 in a special building with a flow rate of up to 45 t / h, pressure 5 kgf / cm2 (0.49 MPa). The special sewerage system is a system of normal operation, important for safety. Failures in the system lead to a highly active environment in the premises of the unit and the environment. The special sewerage system operates in all modes of normal operation of the reactor unit in case of violations of normal operation, not related to the de-energization of the power unit. The object of research is the systems of sampling and special sewerage of NPPs. The subject of research is the reliability of sampling and special sewerage systems of Rivne NPP. The purpose and objectives of research. The aim of the work is to analyze the systems of sampling and special sewerage of Rivne NPP. To achieve this goal it was necessary to perform the following tasks: - to describe the design and technological scheme of the sampling system; - to select the construction materials of the sampling system; - to analyze the functioning of the sampling system; - to analyze the management and control of the special sewerage system; - to select the construction materials of the special sewerage system; - to analyze the functioning of the special sewerage system. In this master’s qualification work, the analysis shows that the sampling system meets the requirements: obtaining a sample for laboratory analysis in normal operation. This is ensured by the capacity of the pipelines, the installation of appropriate throttling devices and the installation of heat exchange equipment, which provides the necessary reduction in sample temperature. The design and technical solutions of the system are developed in accordance with regulatory documentation and meet the requirements, principles and safety criteria. The analysis of the special sewerage system shows that the system meets all the requirements: 1. elements of the system exclude the connection of premises with air through pipelines; 2. the design of the system prevents the coolant of the primary circuit outside the airtight shell in accidents involving the decompression of the primary circuit and increase the pressure in the airtight shell more than 0.3 kgf / cm2 (0.029 MPa); 3. the system provides self-flowing collection of decontaminating aqueous solutions after external decontamination of equipment and premises; 4. the system provides water supply of special sewerage for cleaning SVO-3 special corps with a flow rate of up to 45 m3 / h, pressure 5 kgf / cm2 (0.49 MPa). In the section of economics the calculation of the payback period of the desalination plant intended for the production of demineralized water with the use of the second circuit as a heat carrier is performed. The cost of demineralized SD water received in the plant will be UAH 1.5. The cost of deeply desalinated water is SVGO = 2.24 UAH / m3. In the course of the work, the ACS of the NPP chemical water treatment process was designed. The quality of water treatment at NPPs is closely related to the safety, reliability and economy of operation of equipment, the safety of nuclear power plants. ACS effectively solves the tasks set before it, due to which the goal set before the system is achieved - maintaining the water temperature, pH parameter and water flow at a given level. The scheme of automatic control of chemical water purification is developed, on the basis of which technical means for realization of the formulated functions of control and management have been chosen. Key words: sampling system, special sewerage, high pressure steam pipelines, feed water, power unit.