NEW SYSTEMS TO STORE INFORMATION ON ANY OPERATION DEVIATIONS HAS BEEN INSTALLED AT UNITS 1 AND 2 OF ZAPORIZHZHYA NPP

At units 1 and 2 during recent repair campaigns, a new system was installed – a so-called “black box”. It’s one of many measures performed within the Complex (Consolidated) Safety Upgrade Program.

A “black box” phrase is immediately associated with recorders installed in planes. But it appears that this equipment at a unit reminds real “black boxes” only slightly. At a plant this system is designated to store large information arrays – on state of a unit before, during and after any deviation in operation of a unit.

The system is autonomous. It operates independently from other unit’s systems and gives a complete data packet on causes and parameters of incidents behavior, allows ascertaining an actual algorithm of operation of safety systems and safety important systems, including monitoring and control systems, as well as all deviations from normal operation algorithms of systems, monitoring and recording personnel’s actions.

For this the following is stipulated: recording parameters characterizing an initial event; control signals; parameters characterizing state of safety important systems; parameters, by which implementation of protections is stipulated; parameters characterizing radiation environment; talks of operating personnel via communication systems.

The “black box” system consists of three levels of hierarchy. On the first one – a data input level or a so-called unit part, data are received from systems that are data sources. Furhter, they are transmitted to a data concentration level (an all-unit part), where all parameters from units are processed preliminarily and sorted.

After this, information is delivered to a recording level, where data are processed finally and archived. To assure reliability, duplication and redundancy of both communication channels and separate nodes are used in the system’s architecture.

Besides, the system is distributed in terms of location – the unit level is located at a unit, an all-unit one – in located in a room of a technical support centre, and hardware of the data recording and providing level – in an external crisis centre.

The functions of the system are aimed to increase safety due to analysis of incidents and further development of measures contributing to elimination of remarks detected.

The “black box” system is manufactured at Research and Production Association “Impulse” in Severodonetsk. Specialists from Kharkiv and specialists of Zaporizhzhya NPP have participated in the development. EYuM-10 contractor organization has participated in installation of the systems at units 1 and 2 of ZNPP. With time, in accordance with the schedule of the Complex (Consolidated) Safety Upgrade Program for NPPs, the “black box” systems will be installed at all units of the plant.

Reference: Radiation background in the region, where Zaporizhzhya nuclear power plant is situated, corresponds to natural values and as of 05 May is equal to 8 - 12 μR/hour. Emissions of radioactive substances to the environment don’t exceed fixed permissible values.

Zaporizhzhya NPP – the largest power facility in Ukraine and Europe with the installed capacity of 6 000 MW. 6 units with the capacity of 1 million kW each are operated at ZNPP. The first unit was commissioned in 1984, the second – in 1985, the third – in 1986, the fourth – in 1987, the fifth - in 1989, the sixth – in 1995. Starting from 1984, contribution of Zaporizhzhya NPP to the energy sector of the country has increased from 2 to 22 %.

Source: SE “NNEGC “Energoatom”