Algorithms for processing self-powered neutron detector signals important for determination of local parameters in each part of the VVER core

Abstract

These investigation findings prove the possibility of a engineering solution for VVER core automatic protection during operation in both nominal and transient conditions within ICIS using local parameters (i.e. linear heat power of the most stressed fuel rod, departure from nucleate boiling ratio). Such engineering solution will be implemented by safety system software-hardware (PTK-Z) on the basis of signals coming from in-core neutron flux detectors, temperature sensors, primary coolant flow and coolant pressure transducers. The article presents the following: a list of in-core neutron flux detectors, a list of transducers of primary coolant monitoring for thermal engineering conditions (temperature, flow rate, pressure), whose signals are delivered to the terminals of instrumentation gauges (PTK-Z) for the purpose of actuating safety actions in accordance with local parameters. The paper shows arrangement of in-core neutron flux detector equipment, above view of self-powered neutron detector (SPND) location in safety channels, axial arrangement of SPND along the core, algorithms for processing SPND signals important for determination of local parameters in each part of the core in both normal and abnormal operation conditions.

Review of the Latest Opinions and Theories Regarding the Development of Technical and Agricultural Sciences

“…According to reference data of [288], the water solutions of iodine compounds (NaI, KI), even with their high concentration (10-60%), do not cause considerable corrosion of zirconium and its alloys at temperatures to 100-105 С. Authors of paper of [285] consider that ions of iodine and bromine (content of bromine in ocean water according to the data of [289] is approximately 1000 time higher in comparison with iodine) can cause local corrosion of zirconium alloys. Iodine, as well as bromine, forms oxy acids and the corresponding halogenide-ions when dissolving in water, for example: [287].…”

“…the pollution of zirconium components of fresh FAs with halogenide-ions (Cl -, Bror I -) could lead to increase of general corrosion of zirconium alloy E-110 and development of local types of corrosion on its (pittings, corrosion cracks). This needs the special precautionary measures to be taken during storage of fresh fuel at nuclear power plant (NPP) located in the coastal ocean region to minimize both the amount, and the possibility of getting the sea salts on fuel surface [287][288][289][290].…”

“…Among the chlorides, the basic dissolved compounds are: NaCl (27 g/L), MgCl 2 (6 g/L), KCl and CaCl 2 (1 g/L each) [283][284][285][286][287]. Namely such compounds and in such ratio are recommended to be taken for preparation of solution in climatic tests of the equipment under the conditions of sea (salt) fog [288][289][290].…”